## 2.4.1-dev.XX.0 (Add new changes here, and they will be copied to the change section for the next dev version) ### Language ### Core libraries #### `dart:core` * Update `Uri` class to support [RFC6874](https://tools.ietf.org/html/rfc6874): "%25" or "%" can be appended to the end of a valid IPv6 representing a Zone Identifier. A valid zone ID consists of unreversed character or Percent encoded octet, which was defined in RFC3986. IPv6addrz = IPv6address "%25" ZoneID [29456]: https://github.com/dart-lang/sdk/issues/29456 ### Dart VM ### Tools ## 2.4.0 - 2019-06-24 ### Core libraries #### `dart:isolate` * `TransferableTypedData` class was added to facilitate faster cross-isolate communication of `Uint8List` data. * **Breaking change**: `Isolate.resolvePackageUri` will always throw an `UnsupportedError` when compiled with dart2js or DDC. This was the only remaining API in `dart:isolate` that didn't automatically throw since we dropped support for this library in [Dart 2.0.0][1]. Note that the API already throws in dart2js if the API is used directly without manually setting up a `defaultPackagesBase` hook. [1]: https://github.com/dart-lang/sdk/blob/master/CHANGELOG.md#200---2018-08-07 #### `dart:developer` * Exposed `result`, `errorCode` and `errorDetail` getters in `ServiceExtensionResponse` to allow for better debugging of VM service extension RPC results. #### `dart:io` * Fixed `Cookie` class interoperability with certain websites by allowing the cookie values to be the empty string (Issue [35804][]) and not stripping double quotes from the value (Issue [33327][]) in accordance with RFC 6265. [33327]: https://github.com/dart-lang/sdk/issues/33327 [35804]: https://github.com/dart-lang/sdk/issues/35804 * The `HttpClientResponse` interface has been extended with the addition of a new `compressionState` getter, which specifies whether the body of a response was compressed when it was received and whether it has been automatically uncompressed via `HttpClient.autoUncompress` (Issue [36971][]). As part of this change, a corresponding new enum was added to `dart:io`: `HttpClientResponseCompressionState`. [36971]: https://github.com/dart-lang/sdk/issues/36971 * **Breaking change**: For those implementing the `HttpClientResponse` interface, this is a breaking change, as implementing classes will need to implement the new getter. #### `dart:async` * **Breaking change:** The `await for` allowed `null` as a stream due to a bug in `StreamIterator` class. This bug has now been fixed. #### `dart:core` * **Breaking change:** The `RegExp` interface has been extended with two new constructor named parameters: * `unicode:` (`bool`, default: `false`), for Unicode patterns * `dotAll:` (`bool`, default: `false`), to change the matching behavior of '.' to also match line terminating characters. Appropriate properties for these named parameters have also been added so their use can be detected after construction. In addition, `RegExp` methods that originally returned `Match` objects now return a more specific subtype, `RegExpMatch`, which adds two features: * `Iterable groupNames`, a property that contains the names of all named capture groups * `String namedGroup(String name)`, a method that retrieves the match for the given named capture group This change only affects implementers of the `RegExp` interface; current code using Dart regular expressions will not be affected. ### Language * **Breaking change:** Covariance of type variables used in super-interfaces is now enforced (issue [35097][]). For example, the following code was previously accepted and will now be rejected: ```dart class A {}; class B extends A {}; ``` * The identifier `async` can now be used in asynchronous and generator functions. [35097]: https://github.com/dart-lang/sdk/issues/35097 ### Dart for the Web #### Dart Dev Compiler (DDC) * Improve `NoSuchMethod` errors for failing dynamic calls. Now they include specific information about the nature of the error such as: * Attempting to call a null value. * Calling an object instance with a null `call()` method. * Passing too few or too many arguments. * Passing incorrect named arguments. * Passing too few or too many type arguments. * Passing type arguments to a non-generic method. ### Tools #### Linter The Linter was updated to `0.1.91`, which includes the following changes: * Fixed missed cases in `prefer_const_constructors` * Fixed `prefer_initializing_formals` to no longer suggest API breaking changes * Updated `omit_local_variable_types` to allow explicit `dynamic`s * Fixed null-reference in `unrelated_type_equality_checks` * New lint: `unsafe_html` * Broadened `prefer_null_aware_operators` to work beyond local variables. * Added `prefer_if_null_operators`. * Fixed `prefer_contains` false positives. * Fixed `unnecessary_parenthesis` false positives. * Fixed `prefer_asserts_in_initializer_lists` false positives * Fixed `curly_braces_in_flow_control_structures` to handle more cases * New lint: `prefer_double_quotes` * New lint: `sort_child_properties_last` * Fixed `type_annotate_public_apis` false positive for `static const` initializers #### Pub * `pub publish` will no longer warn about missing dependencies for import statements in `example/`. * OAuth2 authentication will explicitely ask for the `openid` scope. ## 2.3.2 - 2019-06-11 This is a patch version release with a security improvement. ### Security vulnerability * **Security improvement:** On Linux and Android, starting a process with `Process.run`, `Process.runSync`, or `Process.start` would first search the current directory before searching `PATH` (Issue [37101][]). This behavior effectively put the current working directory in the front of `PATH`, even if it wasn't in the `PATH`. This release changes that behavior to only searching the directories in the `PATH` environment variable. Operating systems other than Linux and Android didn't have this behavior and aren't affected by this vulnerability. This vulnerability could result in execution of untrusted code if a command without a slash in its name was run inside an untrusted directory containing an executable file with that name: ```dart Process.run("ls", workingDirectory: "/untrusted/directory") ``` This would attempt to run `/untrusted/directory/ls` if it existed, even though it is not in the `PATH`. It was always safe to instead use an absolute path or a path containing a slash. This vulnerability was introduced in Dart 2.0.0. [37101]: https://github.com/dart-lang/sdk/issues/37101 ## 2.3.1 - 2019-05-21 This is a patch version release with bug fixes. ### Tools #### dart2js * Fixed a bug that caused the compiler to crash when it compiled UI-as-code features within fields (Issue [36864][]). [36864]: https://github.com/dart-lang/sdk/issues/36864 ## 2.3.0 - 2019-05-08 The focus in this release is on the new "UI-as-code" language features which make collections more expressive and declarative. ### Language Flutter is growing rapidly, which means many Dart users are building UI in code out of big deeply-nested expressions. Our goal with 2.3.0 was to [make that kind of code easier to write and maintain][ui-as-code]. Collection literals are a large component, so we focused on three features to make collections more powerful. We'll use list literals in the examples below, but these features also work in map and set literals. [ui-as-code]: https://medium.com/dartlang/making-dart-a-better-language-for-ui-f1ccaf9f546c #### Spread Placing `...` before an expression inside a collection literal unpacks the result of the expression and inserts its elements directly inside the new collection. Where before you had to write something like this: ```dart CupertinoPageScaffold( child: ListView(children: [ Tab2Header() ]..addAll(buildTab2Conversation()) ..add(buildFooter())), ); ``` Now you can write this: ```dart CupertinoPageScaffold( child: ListView(children: [ Tab2Header(), ...buildTab2Conversation(), buildFooter() ]), ); ``` If you know the expression might evaluate to null and you want to treat that as equivalent to zero elements, you can use the null-aware spread `...?`. #### Collection if Sometimes you might want to include one or more elements in a collection only under certain conditions. If you're lucky, you can use a `?:` operator to selectively swap out a single element, but if you want to exchange more than one or omit elements, you are forced to write imperative code like this: ```dart Widget build(BuildContext context) { var children = [ IconButton(icon: Icon(Icons.menu)), Expanded(child: title) ]; if (isAndroid) { children.add(IconButton(icon: Icon(Icons.search))); } return Row(children: children); } ``` We now allow `if` inside collection literals to conditionally omit or (with `else`) swap out an element: ```dart Widget build(BuildContext context) { return Row( children: [ IconButton(icon: Icon(Icons.menu)), Expanded(child: title), if (isAndroid) IconButton(icon: Icon(Icons.search)), ], ); } ``` Unlike the existing `?:` operator, a collection `if` can be composed with spreads to conditionally include or omit multiple items: ```dart Widget build(BuildContext context) { return Row( children: [ IconButton(icon: Icon(Icons.menu)), if (isAndroid) ...[ Expanded(child: title), IconButton(icon: Icon(Icons.search)), ] ], ); } ``` #### Collection for In many cases, the higher-order methods on Iterable give you a declarative way to modify a collection in the context of a single expression. But some operations, especially involving both transforming and filtering, can be cumbersome to express in a functional style. To solve this problem, you can use `for` inside a collection literal. Each iteration of the loop produces an element which is then inserted in the resulting collection. Consider the following code: ```dart var command = [ engineDartPath, frontendServer, ...fileSystemRoots.map((root) => "--filesystem-root=$root"), ...entryPoints .where((entryPoint) => fileExists("lib/$entryPoint.json")) .map((entryPoint) => "lib/$entryPoint"), mainPath ]; ``` With a collection `for`, the code becomes simpler: ```dart var command = [ engineDartPath, frontendServer, for (var root in fileSystemRoots) "--filesystem-root=$root", for (var entryPoint in entryPoints) if (fileExists("lib/$entryPoint.json")) "lib/$entryPoint", mainPath ]; ``` As you can see, all three of these features can be freely composed. For full details of the changes, see [the official proposal][ui-as-code proposal]. [ui-as-code proposal]: https://github.com/dart-lang/language/blob/master/accepted/future-releases/unified-collections/feature-specification.md **Note: These features are not currently supported in *const* collection literals. In a future release, we intend to relax this restriction and allow spread and collection `if` inside const collections.** ### Core library changes #### `dart:isolate` * Added `debugName` property to `Isolate`. * Added `debugName` optional parameter to `Isolate.spawn` and `Isolate.spawnUri`. #### `dart:core` * RegExp patterns can now use lookbehind assertions. * RegExp patterns can now use named capture groups and named backreferences. Currently, named group matches can only be retrieved in Dart either by the implicit index of the named group or by downcasting the returned Match object to the type RegExpMatch. The RegExpMatch interface contains methods for retrieving the available group names and retrieving a match by group name. ### Dart VM * The VM service now requires an authentication code by default. This behavior can be disabled by providing the `--disable-service-auth-codes` flag. * Support for deprecated flags '-c' and '--checked' has been removed. ### Dart for the Web #### dart2js A binary format was added to dump-info. The old JSON format is still available and provided by default, but we are starting to deprecate it. The new binary format is more compact and cheaper to generate. On some large apps we tested, it was 4x faster to serialize and used 6x less memory. To use the binary format today, use `--dump-info=binary`, instead of `--dump-info`. What to expect next? * The [visualizer tool][visualizer] will not be updated to support the new binary format, but you can find several command-line tools at `package:dart2js_info` that provide similar features to those in the visualizer. * The command-line tools in `package:dart2js_info` also work with the old JSON format, so you can start using them even before you enable the new format. * In a future release `--dump-info` will default to `--dump-info=binary`. At that point, there will be an option to fallback to the JSON format, but the visualizer tool will be deprecated. * A release after that, the JSON format will no longer be available from dart2js, but may be available from a command-line tool in `package:dart2js_info`. [visualizer]: https://dart-lang.github.io/dump-info-visualizer/ ### Tools #### dartfmt * Tweak set literal formatting to follow other collection literals. * Add support for "UI as code" features. * Properly format trailing commas in assertions. * Improve indentation of adjacent strings in argument lists. #### Linter The Linter was updated to `0.1.86`, which includes the following changes: * Added the following lints: `prefer_inlined_adds`, `prefer_for_elements_to_map_fromIterable`, `prefer_if_elements_to_conditional_expressions`, `diagnostic_describe_all_properties`. * Updated `file_names` to skip prefixed-extension Dart files (`.css.dart`, `.g.dart`, etc.). * Fixed false positives in `unnecessary_parenthesis`. #### Pub * Added a CHANGELOG validator that complains if you `pub publish` without mentioning the current version. * Removed validation of library names when doing `pub publish`. * Added support for `pub global activate`ing package from a custom pub URL. * Added subcommand: `pub logout`. Logs you out of the current session. #### Dart native Initial support for compiling Dart apps to native machine code has been added. Two new tools have been added to the `bin` folder of the Dart SDK: * `dart2aot`: AOT (ahead-of-time) compiles a Dart program to native machine code. The tool is supported on Windows, macOS, and Linux. * `dartaotruntime`: A small runtime used for executing an AOT compiled program. ## 2.2.0 - 2019-02-26 ### Language Sets now have a literal syntax like lists and maps do: ```dart var set = {1, 2, 3}; ``` Using curly braces makes empty sets ambiguous with maps: ```dart var collection = {}; // Empty set or map? ``` To avoid breaking existing code, an ambiguous literal is treated as a map. To create an empty set, you can rely on either a surrounding context type or an explicit type argument: ```dart // Variable type forces this to be a set: Set set = {}; // A single type argument means this must be a set: var set2 = {}; ``` Set literals are released on all platforms. The `set-literals` experiment flag has been disabled. ### Tools #### Analyzer * The `DEPRECATED_MEMBER_USE` hint was split into two hints: * `DEPRECATED_MEMBER_USE` reports on usage of `@deprecated` members declared in a different package. * `DEPRECATED_MEMBER_USE_FROM_SAME_PACKAGE` reports on usage of `@deprecated` members declared in the same package. #### Linter Upgraded the linter to `0.1.82` which adds the following improvements: * Added `provide_deprecation_message`, and `use_full_hex_values_for_flutter_colors`, `prefer_null_aware_operators`. * Fixed `prefer_const_declarations` set literal false-positives. * Updated `prefer_collection_literals` to support set literals. * Updated `unnecessary_parenthesis` play nicer with cascades. * Removed deprecated lints from the "all options" sample. * Stopped registering "default lints". * Fixed `hash_and_equals` to respect `hashCode` fields. ### Other libraries #### `package:kernel` * **Breaking change:** The `klass` getter on the `InstanceConstant` class in the Kernel AST API has been renamed to `classNode` for consistency. * **Breaking change:** Updated `Link` implementation to utilize true symbolic links instead of junctions on Windows. Existing junctions will continue to work with the new `Link` implementation, but all new links will create symbolic links. To create a symbolic link, Dart must be run with administrative privileges or Developer Mode must be enabled, otherwise a `FileSystemException` will be raised with errno set to `ERROR_PRIVILEGE_NOT_HELD` (Issue [33966]). [33966]: https://github.com/dart-lang/sdk/issues/33966 ## 2.1.1 - 2019-02-18 This is a patch version release. Again, the team's focus was mostly on improving performance and stability after the large changes in Dart 2.0.0. In particular, dart2js now always uses the "fast startup" emitter and the old emitter has been removed. There are a couple of very minor **breaking changes:** * In `dart:io`, adding to a closed `IOSink` now throws a `StateError`. * On the Dart VM, a soundness hole when using `dart:mirrors` to reflectively invoke a method in an incorrect way that violates its static types has been fixed (Issue [35611][]). ### Language This release has no language changes. ### Core library #### `dart:core` * Made `DateTime.parse()` also recognize `,` as a valid decimal separator when parsing from a string (Issue [35576][]). [35576]: https://github.com/dart-lang/sdk/issues/35576 #### `dart:html` * Added methods `Element.removeAttribute`, `Element.removeAttributeNS`, `Element.hasAttribute` and `Element.hasAttributeNS`. (Issue [35655][]). * Improved dart2js compilation of `element.attributes.remove(name)` to generate `element.removeAttribute(name)`, so that there is no performance reason to migrate to the above methods. * Fixed a number of `dart:html` bugs: * Fixed HTML API's with callback typedef to correctly convert Dart functions to JS functions (Issue [35484]). * HttpStatus constants exposed in `dart:html` (Issue [34318]). * Expose DomName `ondblclick` and `dblclickEvent` for Angular analyzer. * Fixed `removeAll` on `classes`; `elements` parameter should be `Iterable` to match Set's `removeAll` not `Iterable` (Issue [30278]). * Fixed a number of methods on DataTransferItem, Entry, FileEntry and DirectoryEntry which previously returned NativeJavaScriptObject. This fixes handling drag/drop of files/directories (Issue [35510]). * Added ability to allow local file access from Chrome browser in ddb. [35655]: https://github.com/dart-lang/sdk/issues/35655 [30278]: https://github.com/dart-lang/sdk/issues/30278 [34318]: https://github.com/dart-lang/sdk/issues/34318 [35484]: https://github.com/dart-lang/sdk/issues/35484 [35510]: https://github.com/dart-lang/sdk/issues/35510 #### `dart:io` * **Breaking Change:** Adding to a closed `IOSink` now throws a `StateError`. * Added ability to get and set low level socket options. [29554]: https://github.com/dart-lang/sdk/issues/29554 ### Dart VM In previous releases it was possible to violate static types using `dart:mirrors`. This code would run without any TypeErrors and print "impossible" output: ```dart import 'dart:mirrors'; class A { void method(int v) { if (v != null && v is! int) { print("This should be impossible: expected null or int got ${v}"); } } } void main() { final obj = A(); reflect(obj).invoke(#method, ['not-an-number']); } ``` This bug is fixed now. Only code that already violates static typing will break. See Issue [35611][] for more details. [35611]: https://github.com/dart-lang/sdk/issues/35611 ### Dart for the Web #### dart2js * The old "full emitter" back-end is removed and dart2js always uses the "fast startup" back-end. The generated fast startup code is optimized to load faster, even though it can be slightly larger. The `--fast-startup` and `--no-fast-startup` are allowed but ignored. They will be removed in a future version. * We fixed a bug in how deferred constructor calls were incorrectly not marked as deferred. The old behavior didn't cause breakages, but was imprecise and pushed more code to the main output unit. * A new deferred split algorithm implementation was added. This implementation fixes a soundness bug and addresses performance issues of the previous implementation, because of that it can have a visible impact on apps. In particular: * We fixed a performance issue which was introduced when we migrated to the common front-end. On large apps, the fix can cut 2/3 of the time spent on this task. * We fixed a bug in how inferred types were categorized (Issue [35311][]). The old behavior was unsound and could produce broken programs. The fix may cause more code to be pulled into the main output unit. This shows up frequently when returning deferred values from closures since the closure's inferred return type is the deferred type. For example, if you have: ```dart () async { await deferred_prefix.loadLibrary(); return new deferred_prefix.Foo(); } ``` The closure's return type is `Future`. The old implementation defers `Foo`, and incorrectly makes the return type `Future`. This may break in places where the correct type is expected. The new implementation will not defer `Foo`, and will place it in the main output unit. If your intent is to defer it, then you need to ensure the return type is not inferred to be `Foo`. For example, you can do so by changing the code to a named closure with a declared type, or by ensuring that the return expression has the type you want, like: ```dart () async { await deferred_prefix.loadLibrary(); return new deferred_prefix.Foo() as dynamic; } ``` Because the new implementation might require you to inspect and fix your app, we exposed two temporary flags: * The `--report-invalid-deferred-types` causes dart2js to run both the old and new algorithms and report any cases where an invalid type was detected. * The `--new-deferred-split` flag enables this new algorithm. * The `--categories=*` flag is being replaced. `--categories=all` was only used for testing and it is no longer supported. `--categories=Server` continues to work at this time but it is deprecated, please use `--server-mode` instead. * The `--library-root` flag was replaced by `--libraries-spec`. This flag is rarely used by developers invoking dart2js directly. It's important for integrating dart2js with build systems. See `--help` for more details on the new flag. [35311]: https://github.com/dart-lang/sdk/issues/35311 ### Tools #### Analyzer * Support for `declarations-casts` has been removed and the `implicit-casts` option now has the combined semantics of both options. This means that users that disable `implicit-casts` might now see errors that were not previously being reported. * New hints added: * `NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR` and `NON_CONST_CALL_TO_LITERAL_CONSTRUCTOR_USING_NEW` inform you when a `@literal` const constructor is called in a non-const context (or with `new`). * `INVALID_LITERAL_ANNOTATION` reports when something other than a const constructor is annotated with `@literal`. * `SUBTYPE_OF_SEALED_CLASS` reports when any class or mixin subclasses (extends, implements, mixes in, or constrains to) a `@sealed` class, and the two are declared in different packages. * `MIXIN_ON_SEALED_CLASS` reports when a `@sealed` class is used as a superclass constraint of a mixin. #### dartdoc Default styles now work much better on mobile. Simple browsing and searching of API docs now work in many cases. Upgraded the linter to `0.1.78` which adds the following improvements: * Added `prefer_final_in_for_each`, `unnecessary_await_in_return`, `use_function_type_syntax_for_parameters`, `avoid_returning_null_for_future`, and `avoid_shadowing_type_parameters`. * Updated `invariant_booleans` status to experimental. * Fixed `type_annotate_public_apis` false positives on local functions. * Fixed `avoid_shadowing_type_parameters` to report shadowed type parameters in generic typedefs. * Fixed `use_setters_to_change_properties` to not wrongly lint overriding methods. * Fixed `cascade_invocations` to not lint awaited targets. * Fixed `prefer_conditional_assignment` false positives. * Fixed `join_return_with_assignment` false positives. * Fixed `cascade_invocations` false positives. * Deprecated `prefer_bool_in_asserts` as it is redundant in Dart 2. ## 2.1.0 - 2018-11-15 This is a minor version release. The team's focus was mostly on improving performance and stability after the large changes in Dart 2.0.0. Notable changes: * We've introduced a dedicated syntax for declaring a mixin. Instead of the `class` keyword, it uses `mixin`: ```dart mixin SetMixin implements Set { ... } ``` The new syntax also enables `super` calls inside mixins. * Integer literals now work in double contexts. When passing a literal number to a function that expects a `double`, you no longer need an explicit `.0` at the end of the number. In releases before 2.1, you need code like this when setting a double like `fontSize`: ```dart TextStyle(fontSize: 18.0) ``` Now you can remove the `.0`: ```dart TextStyle(fontSize: 18) ``` In releases before 2.1, `fontSize : 18` causes a static error. This was a common mistake and source of friction. * **Breaking change:** A number of static errors that should have been detected and reported were not supported in 2.0.0. These are reported now, which means existing incorrect code may show new errors. * `dart:core` now exports `Future` and `Stream`. You no longer need to import `dart:async` to use those very common types. ### Language * Introduced a new syntax for mixin declarations. ```dart mixin SetMixin implements Set { ... } ``` Most classes that are intended to be used as mixins are intended to *only* be used as mixins. The library author doesn't want users to be able to construct or subclass the class. The new syntax makes that intent clear and enforces it in the type system. It is an error to extend or construct a type declared using `mixin`. (You can implement it since mixins expose an implicit interface.) Over time, we expect most mixin declarations to use the new syntax. However, if you have a "mixin" class where users *are* extending or constructing it, note that moving it to the new syntax is a breaking API change since it prevents users from doing that. If you have a type like this that is a mixin as well as being a concrete class and/or superclass, then the existing syntax is what you want. If you need to use a `super` inside a mixin, the new syntax is required. This was previously only allowed with the experimental `--supermixins` flag because it has some complex interactions with the type system. The new syntax addresses those issues and lets you use `super` calls by declaring the superclass constraint your mixin requires: ```dart class Superclass { superclassMethod() { print("in superclass"); } } mixin SomeMixin on Superclass { mixinMethod() { // This is OK: super.superclassMethod(); } } class GoodSub extends Superclass with SomeMixin {} class BadSub extends Object with SomeMixin {} // Error: Since the super() call in mixinMethod() can't find a // superclassMethod() to call, this is prohibited. ``` Even if you don't need to use `super` calls, the new mixin syntax is good because it clearly expresses that you intend the type to be mixed in. * Allow integer literals to be used in double contexts. An integer literal used in a place where a double is required is now interpreted as a double value. The numerical value of the literal needs to be precisely representable as a double value. * Integer literals compiled to JavaScript are now allowed to have any value that can be exactly represented as a JavaScript `Number`. They were previously limited to such numbers that were also representable as signed 64-bit integers. **(Breaking)** A number of static errors that should have been detected and reported were not supported in 2.0.0. These are reported now, which means existing incorrect code may show new errors: * **Setters with the same name as the enclosing class aren't allowed.** (Issue [34225][].) It is not allowed to have a class member with the same name as the enclosing class: ```dart class A { set A(int x) {} } ``` Dart 2.0.0 incorrectly allows this for setters (only). Dart 2.1.0 rejects it. *To fix:* This is unlikely to break anything, since it violates all style guides anyway. * **Constant constructors cannot redirect to non-constant constructors.** (Issue [34161][].) It is not allowed to have a constant constructor that redirects to a non-constant constructor: ```dart class A { const A.foo() : this(); // Redirecting to A() A() {} } ``` Dart 2.0.0 incorrectly allows this. Dart 2.1.0 rejects it. *To fix:* Make the target of the redirection a properly const constructor. * **Abstract methods may not unsoundly override a concrete method.** (Issue [32014][].) Concrete methods must be valid implementations of their interfaces: ```dart class A { num get thing => 2.0; } abstract class B implements A { int get thing; } class C extends A with B {} // 'thing' from 'A' is not a valid override of 'thing' from 'B'. main() { print(new C().thing.isEven); // Expects an int but gets a double. } ``` Dart 2.0.0 allows unsound overrides like the above in some cases. Dart 2.1.0 rejects them. *To fix:* Relax the type of the invalid override, or tighten the type of the overridden method. * **Classes can't implement FutureOr.** (Issue [33744][].) Dart doesn't allow classes to implement the FutureOr type: ```dart class A implements FutureOr {} ``` Dart 2.0.0 allows classes to implement FutureOr. Dart 2.1.0 does not. *To fix:* Don't do this. * **Type arguments to generic typedefs must satisfy their bounds.** (Issue [33308][].) If a parameterized typedef specifies a bound, actual arguments must be checked against it: ```dart class A {} typedef F = A Function(); F f = null; ``` Dart 2.0.0 allows bounds violations like `F` above. Dart 2.1.0 rejects them. *To fix:* Either remove the bound on the typedef parameter, or pass a valid argument to the typedef. * **Constructor invocations must use valid syntax, even with optional `new`.** (Issue [34403][].) Type arguments to generic named constructors go after the class name, not the constructor name, even when used without an explicit `new`: ```dart class A { A.foo() {} } main() { A.foo(); // Incorrect syntax, was accepted in 2.0.0. A.foo(); // Correct syntax. } ``` Dart 2.0.0 accepts the incorrect syntax when the `new` keyword is left out. Dart 2.1.0 correctly rejects this code. *To fix:* Move the type argument to the correct position after the class name. * **Instance members should shadow prefixes.** (Issue [34498][].) If the same name is used as an import prefix and as a class member name, then the class member name takes precedence in the class scope. ```dart import 'dart:core'; import 'dart:core' as core; class A { core.List get core => null; // "core" refers to field, not prefix. } ``` Dart 2.0.0 incorrectly resolves the use of `core` in `core.List` to the prefix name. Dart 2.1.0 correctly resolves this to the field name. *To fix:* Change the prefix name to something which does not clash with the instance member. * **Implicit type arguments in extends clauses must satisfy the class bounds.** (Issue [34532][].) Implicit type arguments for generic classes are computed if not passed explicitly, but when used in an `extends` clause they must be checked for validity: ```dart class Foo {} class Bar> {} class Baz extends Bar {} // Should error because Bar completes to Bar ``` Dart 2.0.0 accepts the broken code above. Dart 2.1.0 rejects it. *To fix:* Provide explicit type arguments to the superclass that satisfy the bound for the superclass. * **Mixins must correctly override their superclasses.** (Issue [34235][].) In some rare cases, combinations of uses of mixins could result in invalid overrides not being caught: ```dart class A { num get thing => 2.0; } class M1 { int get thing => 2; } class B = A with M1; class M2 { num get thing => 2.0; } class C extends B with M2 {} // 'thing' from 'M2' not a valid override. main() { M1 a = new C(); print(a.thing.isEven); // Expects an int but gets a double. } ``` Dart 2.0.0 accepts the above example. Dart 2.1.0 rejects it. *To fix:* Ensure that overriding methods are correct overrides of their superclasses, either by relaxing the superclass type, or tightening the subclass/mixin type. [32014]: https://github.com/dart-lang/sdk/issues/32014 [33308]: https://github.com/dart-lang/sdk/issues/33308 [33744]: https://github.com/dart-lang/sdk/issues/33744 [34161]: https://github.com/dart-lang/sdk/issues/34161 [34225]: https://github.com/dart-lang/sdk/issues/34225 [34235]: https://github.com/dart-lang/sdk/issues/34235 [34403]: https://github.com/dart-lang/sdk/issues/34403 [34498]: https://github.com/dart-lang/sdk/issues/34498 [34532]: https://github.com/dart-lang/sdk/issues/34532 ### Core libraries #### `dart:async` * Fixed a bug where calling `stream.take(0).drain(value)` would not correctly forward the `value` through the returned `Future`. * Added a `StreamTransformer.fromBind` constructor. * Updated `Stream.fromIterable` to send a done event after the error when the iterator's `moveNext` throws, and handle if the `current` getter throws (issue [33431][]). [33431]: http://dartbug.com/33431 #### `dart:core` * Added `HashMap.fromEntries` and `LinkedHashmap.fromEntries` constructors. * Added `ArgumentError.checkNotNull` utility method. * Made `Uri` parsing more permissive about `[` and `]` occurring in the path, query or fragment, and `#` occurring in fragment. * Exported `Future` and `Stream` from `dart:core`. * Added operators `&`, `|` and `^` to `bool`. * Added missing methods to `UnmodifiableMapMixin`. Some maps intended to be unmodifiable incorrectly allowed new methods added in Dart 2 to succeed. * Deprecated the `provisional` annotation and the `Provisional` annotation class. These should have been removed before releasing Dart 2.0, and they have no effect. #### `dart:html` Fixed Service Workers and any Promise/Future API with a Dictionary parameter. APIs in dart:html (that take a Dictionary) will receive a Dart Map parameter. The Map parameter must be converted to a Dictionary before passing to the browser's API. Before this change, any Promise/Future API with a Map/Dictionary parameter never called the Promise and didn't return a Dart Future - now it does. This caused a number of breaks especially in Service Workers (register, etc.). Here is a complete list of the fixed APIs: * BackgroundFetchManager * `Future fetch(String id, Object requests, [Map options])` * CacheStorage * `Future match(/*RequestInfo*/ request, [Map options])` * CanMakePayment * `Future> matchAll([Map options])` * CookieStore * `Future getAll([Map options])` * `Future set(String name, String value, [Map options])` * CredentialsContainer * `Future get([Map options])` * `Future create([Map options])` * ImageCapture * `Future setOptions(Map photoSettings)` * MediaCapabilities * `Future decodingInfo(Map configuration)` * `Future encodingInfo(Map configuration)` * MediaStreamTrack * `Future applyConstraints([Map constraints])` * Navigator * `Future requestKeyboardLock([List keyCodes])` * `Future requestMidiAccess([Map options])` * `Future share([Map data])` * OffscreenCanvas * `Future convertToBlob([Map options])` * PaymentInstruments * `Future set(String instrumentKey, Map details)` * Permissions * `Future query(Map permission)` * `Future request(Map permissions)` * `Future revoke(Map permission)` * PushManager * `Future permissionState([Map options])` * `Future subscribe([Map options])` * RtcPeerConnection * Changed: ```dart Future createAnswer([options_OR_successCallback, RtcPeerConnectionErrorCallback failureCallback, Map mediaConstraints]) ``` to: ```dart Future createAnswer([Map options]) ``` * Changed: ```dart Future createOffer([options_OR_successCallback, RtcPeerConnectionErrorCallback failureCallback, Map rtcOfferOptions]) ``` to: ```dart Future createOffer([Map options]) ``` * Changed: ```dart Future setLocalDescription(Map description, VoidCallback successCallback, [RtcPeerConnectionErrorCallback failureCallback]) ``` to: ```dart Future setLocalDescription(Map description) ``` * Changed: ```dart Future setLocalDescription(Map description, VoidCallback successCallback, [RtcPeerConnectionErrorCallback failureCallback]) ``` to: ```dart Future setRemoteDescription(Map description) ``` * ServiceWorkerContainer * `Future register(String url, [Map options])` * ServiceWorkerRegistration * `Future> getNotifications([Map filter])` * `Future showNotification(String title, [Map options])` * VRDevice * `Future requestSession([Map options])` * `Future supportsSession([Map options])` * VRSession * `Future requestFrameOfReference(String type, [Map options])` * Window * `Future fetch(/*RequestInfo*/ input, [Map init])` * WorkerGlobalScope * `Future fetch(/*RequestInfo*/ input, [Map init])` In addition, exposed Service Worker "self" as a static getter named "instance". The instance is exposed on four different Service Worker classes and can throw a InstanceTypeError if the instance isn't of the class expected (WorkerGlobalScope.instance will always work and not throw): * `SharedWorkerGlobalScope.instance` * `DedicatedWorkerGlobalScope.instance` * `ServiceWorkerGlobalScope.instance` * `WorkerGlobalScope.instance` #### `dart:io` * Added new HTTP status codes. ### Dart for the Web #### dart2js * **(Breaking)** Duplicate keys in a const map are not allowed and produce a compile-time error. Dart2js used to report this as a warning before. This was already an error in dartanalyzer and DDC and will be an error in other tools in the future as well. * Added `-O` flag to tune optimization levels. For more details run `dart2js -h -v`. We recommend to enable optimizations using the `-O` flag instead of individual flags for each optimization. This is because the `-O` flag is intended to be stable and continue to work in future versions of dart2js, while individual flags may come and go. At this time we recommend to test and debug with `-O1` and to deploy with `-O3`. ### Tool Changes #### dartfmt * Addressed several dartfmt issues when used with the new CFE parser. #### Linter Bumped the linter to `0.1.70` which includes the following new lints: * `avoid_returning_null_for_void` * `sort_pub_dependencies` * `prefer_mixin` * `avoid_implementing_value_types` * `flutter_style_todos` * `avoid_void_async` * `prefer_void_to_null` and improvements: * Fixed NPE in `prefer_iterable_whereType`. * Improved message display for `await_only_futures` * Performance improvements for `null_closures` * Mixin support * Updated `sort_constructors_first` to apply to all members. * Updated `unnecessary_this` to work on field initializers. * Updated `unawaited_futures` to ignore assignments within cascades. * Improved handling of constant expressions with generic type params. * NPE fix for `invariant_booleans`. * Improved docs for `unawaited_futures`. * Updated `unawaited_futures` to check cascades. * Relaxed `void_checks` (allowing `T Function()` to be assigned to `void Function()`). * Fixed false positives in `lines_longer_than_80_chars`. #### Pub * Renamed the `--checked` flag to `pub run` to `--enable-asserts`. * Pub will no longer delete directories named "packages". * The `--packages-dir` flag is now ignored. ## 2.0.0 - 2018-08-07 This is the first major version release of Dart since 1.0.0, so it contains many significant changes across all areas of the platform. Large changes include: * **(Breaking)** The unsound optional static type system has been replaced with a sound static type system using type inference and runtime checks. This was formerly called "[strong mode][]" and only used by the Dart for web products. Now it is the one official static type system for the entire platform and replaces the previous "checked" and "production" modes. * **(Breaking)** Functions marked `async` now run synchronously until the first `await` statement. Previously, they would return to the event loop once at the top of the function body before any code runs ([issue 30345][]). * **(Breaking)** Constants in the core libraries have been renamed from `SCREAMING_CAPS` to `lowerCamelCase`. * **(Breaking)** Many new methods have been added to core library classes. If you implement the interfaces of these classes, you will need to implement the new methods. * **(Breaking)** "dart:isolate" and "dart:mirrors" are no longer supported when using Dart for the web. They are still supported in the command-line VM. * **(Breaking)** Pub's transformer-based build system has been [replaced by a new build system][transformers]. * The `new` keyword is optional and can be omitted. Likewise, `const` can be omitted inside a const context ([issue 30921][]). * Dartium is no longer maintained or supported. [issue 30345]: https://github.com/dart-lang/sdk/issues/30345 [issue 30921]: https://github.com/dart-lang/sdk/issues/30921 [strong mode]: https://www.dartlang.org/guides/language/sound-dart [transformers]: https://www.dartlang.org/tools/pub/obsolete ### Language * "[Strong mode][]" is now the official type system of the language. * The `new` keyword is optional and can be omitted. Likewise, `const` can be omitted inside a const context. * A string in a `part of` declaration may now be used to refer to the library this file is part of. A library part can now declare its library as either: ```dart part of name.of.library; ``` Or: ```dart part of "uriReferenceOfLibrary.dart"; ``` This allows libraries with no library declarations (and therefore no name) to have parts, and it allows tools to easily find the library of a part file. The Dart 1.0 syntax is supported but deprecated. * Functions marked `async` now run synchronously until the first `await` statement. Previously, they would return to the event loop once at the top of the function body before any code runs ([issue 30345][]). * The type `void` is now a Top type like `dynamic`, and `Object`. It also now has new errors for being used where not allowed (such as being assigned to any non-`void`-typed parameter). Some libraries (importantly, mockito) may need to be updated to accept void values to keep their APIs working. * Future flattening is now done only as specified in the Dart 2.0 spec, rather than more broadly. This means that the following code has an error on the assignment to `y`. ```dart test() { Future f; var x = f.then>>((x) => []); Future> y = x; } ``` * Invocations of `noSuchMethod()` receive default values for optional args. The following program used to print "No arguments passed", and now prints "First argument is 3". ```dart abstract class B { void m([int x = 3]); } class A implements B { noSuchMethod(Invocation i) { if (i.positionalArguments.length == 0) { print("No arguments passed"); } else { print("First argument is ${i.positionalArguments[0]}"); } } } void main() { A().m(); } ``` * Bounds on generic functions are invariant. The following program now issues an invalid override error ([issue 29014][sdk#29014]): ```dart class A { void f() {} } class B extends A { @override void f() {} } ``` * Numerous corner case bugs around return statements in synchronous and asynchronous functions fixed. Specifically: * Issues [31887][issue 31887], [32881][issue 32881]. Future flattening should not be recursive. * Issues [30638][issue 30638], [32233][issue 32233]. Incorrect downcast errors with `FutureOr`. * Issue [32233][issue 32233]. Errors when returning `FutureOr`. * Issue [33218][issue 33218]. Returns in functions with void related types. * Issue [31278][issue 31278]. Incorrect hint on empty returns in async. functions. * An empty `return;` in an async function with return type `Future` does not report an error. * `return exp;` where `exp` has type `void` in an async function is now an error unless the return type of the function is `void` or `dynamic`. * Mixed return statements of the form `return;` and `return exp;` are now allowed when `exp` has type `void`. * A compile time error is emitted for any literal which cannot be exactly represented on the target platform. As a result, dart2js and DDC report errors if an integer literal cannot be represented exactly in JavaScript ([issue 33282][]). * New member conflict rules have been implemented. Most cases of conflicting members with the same name are now static errors ([issue 33235][]). [sdk#29014]: https://github.com/dart-lang/sdk/issues/29014 [issue 30638]: https://github.com/dart-lang/sdk/issues/30638 [issue 31278]: https://github.com/dart-lang/sdk/issues/31278 [issue 31887]: https://github.com/dart-lang/sdk/issues/31887 [issue 32233]: https://github.com/dart-lang/sdk/issues/32233 [issue 32881]: https://github.com/dart-lang/sdk/issues/32881 [issue 33218]: https://github.com/dart-lang/sdk/issues/33218 [issue 33235]: https://github.com/dart-lang/sdk/issues/33235 [issue 33282]: https://github.com/dart-lang/sdk/issues/33282 [issue 33341]: https://github.com/dart-lang/sdk/issues/33341 ### Core libraries * Replaced `UPPER_CASE` constant names with `lowerCamelCase`. For example, `HTML_ESCAPE` is now `htmlEscape`. * The Web libraries were re-generated using Chrome 63 WebIDLs ([details][idl]). [idl]: https://github.com/dart-lang/sdk/wiki/Chrome-63-Dart-Web-Libraries #### `dart:async` * `Stream`: * Added `cast` and `castFrom`. * Changed `firstWhere`, `lastWhere`, and `singleWhere` to return `Future` and added an optional `T orElse()` callback. * `StreamTransformer`: added `cast` and `castFrom`. * `StreamTransformerBase`: new class. * `Timer`: added `tick` property. * `Zone` * changed to be strong-mode clean. This required some breaking API changes. See https://goo.gl/y9mW2x for more information. * Added `bindBinaryCallbackGuarded`, `bindCallbackGuarded`, and `bindUnaryCallbackGuarded`. * Renamed `Zone.ROOT` to `Zone.root`. * Removed the deprecated `defaultValue` parameter on `Stream.firstWhere` and `Stream.lastWhere`. * Changed an internal lazily-allocated reusable "null future" to always belong to the root zone. This avoids race conditions where the first access to the future determined which zone it would belong to. The zone is only used for *scheduling* the callback of listeners, the listeners themselves will run in the correct zone in any case. Issue [#32556](http://dartbug.com/32556). #### `dart:cli` * *New* "provisional" library for CLI-specific features. * `waitFor`: function that suspends a stack to wait for a `Future` to complete. #### `dart:collection` * `MapBase`: added `mapToString`. * `LinkedHashMap` no longer implements `HashMap` * `LinkedHashSet` no longer implements `HashSet`. * Added `of` constructor to `Queue`, `ListQueue`, `DoubleLinkedQueue`, `HashSet`, `LinkedHashSet`, `SplayTreeSet`, `Map`, `HashMap`, `LinkedHashMap`, `SplayTreeMap`. * Removed `Maps` class. Extend `MapBase` or mix in `MapMixin` instead to provide map method implementations for a class. * Removed experimental `Document` method `getCSSCanvasContext` and property `supportsCssCanvasContext`. * Removed obsolete `Element` property `xtag` no longer supported in browsers. * Exposed `ServiceWorker` class. * Added constructor to `MessageChannel` and `MessagePort` `addEventListener` automatically calls `start` method to receive queued messages. #### `dart:convert` * `Base64Codec.decode` return type is now `Uint8List`. * `JsonUnsupportedObjectError`: added `partialResult` property * `LineSplitter` now implements `StreamTransformer` instead of `Converter`. It retains `Converter` methods `convert` and `startChunkedConversion`. * `Utf8Decoder` when compiled with dart2js uses the browser's `TextDecoder` in some common cases for faster decoding. * Renamed `ASCII`, `BASE64`, `BASE64URI`, `JSON`, `LATIN1` and `UTF8` to `ascii`, `base64`, `base64Uri`, `json`, `latin1` and `utf8`. * Renamed the `HtmlEscapeMode` constants `UNKNOWN`, `ATTRIBUTE`, `SQ_ATTRIBUTE` and `ELEMENT` to `unknown`, `attribute`, `sqAttribute` and `elements`. * Added `jsonEncode`, `jsonDecode`, `base64Encode`, `base64UrlEncode` and `base64Decode` top-level functions. * Changed return type of `encode` on `AsciiCodec` and `Latin1Codec`, and `convert` on `AsciiEncoder`, `Latin1Encoder`, to `Uint8List`. * Allow `utf8.decoder.fuse(json.decoder)` to ignore leading Unicode BOM. #### `dart:core` * `BigInt` class added to support integers greater than 64-bits. * Deprecated the `proxy` annotation. * Added `Provisional` class and `provisional` field. * Added `pragma` annotation. * `RegExp` added static `escape` function. * The `Uri` class now correctly handles paths while running on Node.js on Windows. * Core collection changes: * `Iterable` added members `cast`, `castFrom`, `followedBy` and `whereType`. * `Iterable.singleWhere` added `orElse` parameter. * `List` added `+` operator, `first` and `last` setters, and `indexWhere` and `lastIndexWhere` methods, and static `copyRange` and `writeIterable` methods. * `Map` added `fromEntries` constructor. * `Map` added `addEntries`, `cast`, `entries`, `map`, `removeWhere`, `update` and `updateAll` members. * `MapEntry`: new class used by `Map.entries`. * *Note*: if a class extends `IterableBase`, `ListBase`, `SetBase` or `MapBase` (or uses the corresponding mixins) from `dart:collection`, the new members are implemented automatically. * Added `of` constructor to `List`, `Set`, `Map`. * Renamed `double.INFINITY`, `double.NEGATIVE_INFINITY`, `double.NAN`, `double.MAX_FINITE` and `double.MIN_POSITIVE` to `double.infinity`, `double.negativeInfinity`, `double.nan`, `double.maxFinite` and `double.minPositive`. * Renamed the following constants in `DateTime` to lower case: `MONDAY` through `SUNDAY`, `DAYS_PER_WEEK` (as `daysPerWeek`), `JANUARY` through `DECEMBER` and `MONTHS_PER_YEAR` (as `monthsPerYear`). * Renamed the following constants in `Duration` to lower case: `MICROSECONDS_PER_MILLISECOND` to `microsecondsPerMillisecond`, `MILLISECONDS_PER_SECOND` to `millisecondsPerSecond`, `SECONDS_PER_MINUTE` to `secondsPerMinute`, `MINUTES_PER_HOUR` to `minutesPerHour`, `HOURS_PER_DAY` to `hoursPerDay`, `MICROSECONDS_PER_SECOND` to `microsecondsPerSecond`, `MICROSECONDS_PER_MINUTE` to `microsecondsPerMinute`, `MICROSECONDS_PER_HOUR` to `microsecondsPerHour`, `MICROSECONDS_PER_DAY` to `microsecondsPerDay`, `MILLISECONDS_PER_MINUTE` to `millisecondsPerMinute`, `MILLISECONDS_PER_HOUR` to `millisecondsPerHour`, `MILLISECONDS_PER_DAY` to `millisecondsPerDay`, `SECONDS_PER_HOUR` to `secondsPerHour`, `SECONDS_PER_DAY` to `secondsPerDay`, `MINUTES_PER_DAY` to `minutesPerDay`, and `ZERO` to `zero`. * Added `typeArguments` to `Invocation` class. * Added constructors to invocation class that allows creation of `Invocation` objects directly, without going through `noSuchMethod`. * Added `unaryMinus` and `empty` constant symbols on the `Symbol` class. * Changed return type of `UriData.dataAsBytes` to `Uint8List`. * Added `tryParse` static method to `int`, `double`, `num`, `BigInt`, `Uri` and `DateTime`. * Deprecated `onError` parameter on `int.parse`, `double.parse` and `num.parse`. * Deprecated the `NoSuchMethodError` constructor. * `int.parse` on the VM no longer accepts unsigned hexadecimal numbers greater than or equal to `2**63` when not prefixed by `0x`. (SDK issue [32858](https://github.com/dart-lang/sdk/issues/32858)) #### `dart:developer` * `Flow` class added. * `Timeline.startSync` and `Timeline.timeSync` now accept an optional parameter `flow` of type `Flow`. The `flow` parameter is used to generate flow timeline events that are enclosed by the slice described by `Timeline.{start,finish}Sync` and `Timeline.timeSync`. #### `dart:html` * Removed deprecated `query` and `queryAll`. Use `querySelector` and `querySelectorAll`. #### `dart:io` * `HttpStatus` added `UPGRADE_REQUIRED`. * `IOOverrides` and `HttpOverrides` added to aid in writing tests that wish to mock varios `dart:io` objects. * `Platform.operatingSystemVersion` added that gives a platform-specific String describing the version of the operating system. * `ProcessStartMode.INHERIT_STDIO` added, which allows a child process to inherit the parent's stdio handles. * `RawZLibFilter` added for low-level access to compression and decompression routines. * Unified backends for `SecureSocket`, `SecurityContext`, and `X509Certificate` to be consistent across all platforms. All `SecureSocket`, `SecurityContext`, and `X509Certificate` properties and methods are now supported on iOS and OSX. * `SecurityContext.alpnSupported` deprecated as ALPN is now supported on all platforms. * `SecurityContext`: added `withTrustedRoots` named optional parameter constructor, which defaults to false. * Added a `timeout` parameter to `Socket.connect`, `RawSocket.connect`, `SecureSocket.connect` and `RawSecureSocket.connect`. If a connection attempt takes longer than the duration specified in `timeout`, a `SocketException` will be thrown. Note: if the duration specified in `timeout` is greater than the OS level timeout, a timeout may occur sooner than specified in `timeout`. * `Stdin.hasTerminal` added, which is true if stdin is attached to a terminal. * `WebSocket` added static `userAgent` property. * `RandomAccessFile.close` returns `Future` * Added `IOOverrides.socketConnect`. * Added Dart-styled constants to `ZLibOptions`, `FileMode`, `FileLock`, `FileSystemEntityType`, `FileSystemEvent`, `ProcessStartMode`, `ProcessSignal`, `InternetAddressType`, `InternetAddress`, `SocketDirection`, `SocketOption`, `RawSocketEvent`, and `StdioType`, and deprecated the old `SCREAMING_CAPS` constants. * Added the Dart-styled top-level constants `zlib`, `gzip`, and `systemEncoding`, and deprecated the old `SCREAMING_CAPS` top-level constants. * Removed the top-level `FileMode` constants `READ`, `WRITE`, `APPEND`, `WRITE_ONLY`, and `WRITE_ONLY_APPEND`. Please use e.g. `FileMode.read` instead. * Added `X509Certificate.der`, `X509Certificate.pem`, and `X509Certificate.sha1`. * Added `FileSystemEntity.fromRawPath` constructor to allow for the creation of `FileSystemEntity` using `Uint8List` buffers. * Dart-styled constants have been added for `HttpStatus`, `HttpHeaders`, `ContentType`, `HttpClient`, `WebSocketStatus`, `CompressionOptions`, and `WebSocket`. The `SCREAMING_CAPS` constants are marked deprecated. Note that `HttpStatus.CONTINUE` is now `HttpStatus.continue_`, and that e.g. `HttpHeaders.FIELD_NAME` is now `HttpHeaders.fieldNameHeader`. * Deprecated `Platform.packageRoot`, which is only used for `packages/` directory resolution which is no longer supported. It will now always return null, which is a value that was always possible for it to return previously. * Adds `HttpClient.connectionTimeout`. * Adds `{Socket,RawSocket,SecureSocket}.startConnect`. These return a `ConnectionTask`, which can be used to cancel an in-flight connection attempt. #### `dart:isolate` * Make `Isolate.spawn` take a type parameter representing the argument type of the provided function. This allows functions with arguments types other than `Object` in strong mode. * Rename `IMMEDIATE` and `BEFORE_NEXT_EVENT` on `Isolate` to `immediate` and `beforeNextEvent`. * Deprecated `Isolate.packageRoot`, which is only used for `packages/` directory resolution which is no longer supported. It will now always return null, which is a value that was always possible for it to return previously. * Deprecated `packageRoot` parameter in `Isolate.spawnUri`, which is was previously used only for `packages/` directory resolution. That style of resolution is no longer supported in Dart 2. #### `dart.math` * Renamed `E`, `LN10`, `LN`, `LOG2E`, `LOG10E`, `PI`, `SQRT1_2` and `SQRT2` to `e`, `ln10`, `ln`, `log2e`, `log10e`, `pi`, `sqrt1_2` and `sqrt2`. #### `dart.mirrors` * Added `IsolateMirror.loadUri`, which allows dynamically loading additional code. * Marked `MirrorsUsed` as deprecated. The `MirrorsUsed` annotation was only used to inform the dart2js compiler about how mirrors were used, but dart2js no longer supports the mirrors library altogether. #### `dart:typed_data` * Added `Unmodifiable` view classes over all `List` types. * Renamed `BYTES_PER_ELEMENT` to `bytesPerElement` on all typed data lists. * Renamed constants `XXXX` through `WWWW` on `Float32x4` and `Int32x4` to lower-case `xxxx` through `wwww`. * Renamed `Endinanness` to `Endian` and its constants from `BIG_ENDIAN`, `LITTLE_ENDIAN` and `HOST_ENDIAN` to `little`, `big` and `host`. ### Dart VM * Support for MIPS has been removed. * Dart `int` is now restricted to 64 bits. On overflow, arithmetic operations wrap around, and integer literals larger than 64 bits are not allowed. See https://github.com/dart-lang/sdk/blob/master/docs/language/informal/int64.md for details. * The Dart VM no longer attempts to perform `packages/` directory resolution (for loading scripts, and in `Isolate.resolveUri`). Users relying on `packages/` directories should switch to `.packages` files. ### Dart for the Web * Expose JavaScript Promise APIs using Dart futures. For example, `BackgroundFetchManager.get` is defined as: ```dart Future get(String id) ``` It can be used like: ```dart BackgroundFetchRegistration result = await fetchMgr.get('abc'); ``` The underlying JS Promise-to-Future mechanism will be exposed as a public API in the future. #### Dart Dev Compiler (DDC) * dartdevc will no longer throw an error from `is` checks that return a different result in weak mode (SDK [issue 28988][sdk#28988]). For example: ```dart main() { List l = []; // Prints "false", does not throw. print(l is List); } ``` * Failed `as` casts on `Iterable`, `Map`, `Future`, and `Stream` are no longer ignored. These failures were ignored to make it easier to migrate Dart 1 code to strong mode, but ignoring them is a hole in the type system. This closes part of that hole. (We still need to stop ignoring "as" cast failures on function types, and implicit cast failures on the above types and function types.) [sdk#28988]: https://github.com/dart-lang/sdk/issues/28988 #### dart2js * dart2js now compiles programs with Dart 2.0 semantics. Apps are expected to be bigger than before, because Dart 2.0 has many more implicit checks (similar to the `--checked` flag in Dart 1.0). We exposed a `--omit-implicit-checks` flag which removes most of the extra implicit checks. Only use this if you have enough test coverage to know that the app will work well without the checks. If a check would have failed and it is omitted, your app may crash or behave in unexpected ways. This flag is similar to `--trust-type-annotations` in Dart 1.0. * dart2js replaced its front-end with the common front-end (CFE). Thanks to the CFE, dart2js errors are more consistent with all other Dart tools. * dart2js replaced its source-map implementation. There aren't any big differences, but more data is emitted for synthetic code generated by the compiler. * `dart:mirrors` support was removed. Frameworks are encouraged to use code-generation instead. Conditional imports indicate that mirrors are not supported, and any API in the mirrors library will throw at runtime. * The generated output of dart2js can now be run as a webworker. * `dart:isolate` support was removed. To launch background tasks, please use webworkers instead. APIs for webworkers can be accessed from `dart:html` or JS-interop. * dart2js no longer supports the `--package-root` flag. This flag was deprecated in favor of `--packages` long ago. ### Tool Changes #### Analyzer * The analyzer will no longer issue a warning when a generic type parameter is used as the type in an instance check. For example: ```dart test() { print(3 is T); // No warning } ``` * New static checking of `@visibleForTesting` elements. Accessing a method, function, class, etc. annotated with `@visibleForTesting` from a file _not_ in a `test/` directory will result in a new hint ([issue 28273][]). * Static analysis now respects functions annotated with `@alwaysThrows` ([issue 31384][]). * New hints added: * `NULL_AWARE_BEFORE_OPERATOR` when an operator is used after a null-aware access. For example: ```dart x?.a - ''; // HINT ``` * `NULL_AWARE_IN_LOGICAL_OPERATOR` when an expression with null-aware access is used as a condition in logical operators. For example: ```dart x.a || x?.b; // HINT ``` * The command line analyzer (dartanalyzer) and the analysis server no longer treat directories named `packages` specially. Previously they had ignored these directories - and their contents - from the point of view of analysis. Now they'll be treated just as regular directories. This special-casing of `packages` directories was to support using symlinks for package: resolution; that functionality is now handled by `.packages` files. * New static checking of duplicate shown or hidden names in an export directive ([issue 33182][]). * The analysis server will now only analyze code in Dart 2 mode ('strong mode'). It will emit warnings for analysis options files that have `strong-mode: false` set (and will emit a hint for `strong-mode: true`, which is no longer necessary). * The dartanalyzer `--strong` flag is now deprecated and ignored. The command-line analyzer now only analyzes code in strong mode. [issue 28273]: https://github.com/dart-lang/sdk/issues/28273 [issue 31384]: https://github.com/dart-lang/sdk/issues/31384 [issue 33182]: https://github.com/dart-lang/sdk/issues/33182 #### dartfmt * Support `assert()` in const constructor initializer lists. * Better formatting for multi-line strings in argument lists. * Force splitting an empty block as the then body of an if with an else. * Support metadata annotations on enum cases. * Add `--fix` to remove unneeded `new` and `const` keywords, and change `:` to `=` before named parameter default values. * Change formatting rules around static methods to uniformly format code with and without `new` and `const`. * Format expressions inside string interpolation. #### Pub * Pub has a brand new version solver! It supports all the same features as the old version solver, but it's much less likely to stall out on difficult package graphs, and it's much clearer about why a solution can't be found when version solving fails. * Remove support for transformers, `pub build`, and `pub serve`. Use the [new build system][transformers] instead. * There is now a default SDK constraint of `<2.0.0` for any package with no existing upper bound. This allows us to move more safely to 2.0.0. All new packages published on pub will now require an upper bound SDK constraint so future major releases of Dart don't destabilize the package ecosystem. All SDK constraint exclusive upper bounds are now treated as though they allow pre-release versions of that upper bound. For example, the SDK constraint `>=1.8.0 <2.0.0` now allows pre-release SDK versions such as `2.0.0-beta.3.0`. This allows early adopters to try out packages that don't explicitly declare support for the new version yet. You can disable this functionality by setting the `PUB_ALLOW_PRERELEASE_SDK` environment variable to `false`. * Allow depending on a package in a subdirectory of a Git repository. Git dependencies may now include a `path` parameter, indicating that the package exists in a subdirectory of the Git repository. For example: ```yaml dependencies: foobar: git: url: git://github.com/dart-lang/multi_package_repo path: pkg/foobar ``` * Added an `--executables` option to `pub deps` command. This will list all available executables that can be run with `pub run`. * The Flutter `sdk` source will now look for packages in `flutter/bin/cache/pkg/` as well as `flutter/packages/`. In particular, this means that packages can depend on the `sky_engine` package from the `sdk` source ([issue 1775][pub#1775]). * Pub now caches compiled packages and snapshots in the `.dart_tool/pub` directory, rather than the `.pub` directory ([issue 1795][pub#1795]). * Other bug fixes and improvements. [issue 30246]: https://github.com/dart-lang/sdk/issues/30246 [pub#1679]: https://github.com/dart-lang/pub/issues/1679 [pub#1684]: https://github.com/dart-lang/pub/issues/1684 [pub#1775]: https://github.com/dart-lang/pub/issues/1775 [pub#1795]: https://github.com/dart-lang/pub/issues/1795 [pub#1823]: https://github.com/dart-lang/pub/issues/1823 ## 1.24.3 - 2017-12-14 * Fix for constructing a new SecurityContext that contains the built-in certificate authority roots ([issue 24693](https://github.com/dart-lang/sdk/issues/24693)). ### Core library changes * `dart:io` * Unified backends for `SecureSocket`, `SecurityContext`, and `X509Certificate` to be consistent across all platforms. All `SecureSocket`, `SecurityContext`, and `X509Certificate` properties and methods are now supported on iOS and OSX. ## 1.24.2 - 2017-06-22 * Fixes for debugging in Dartium. * Fix DevConsole crash with JS ([issue 29873](https://github.com/dart-lang/sdk/issues/29873)). * Fix debugging in WebStorm, NULL returned for JS objects ([issue 29854](https://github.com/dart-lang/sdk/issues/29854)). ## 1.24.1 - 2017-06-14 * Bug fixes for dartdevc support in `pub serve`. * Fixed module config invalidation logic so modules are properly recalculated when package layout changes. * Fixed exception when handling require.js errors that aren't script load errors. * Fixed an issue where requesting the bootstrap.js file before the dart.js file would result in a 404. * Fixed a Safari issue during bootstrapping (note that Safari is still not officially supported but does work for trivial examples). * Fix for a Dartium issue where there was no sound in checked mode ([issue 29810](https://github.com/dart-lang/sdk/issues/29810)). ## 1.24.0 - 2017-06-12 ### Language * During a dynamic type check, `void` is not required to be `null` anymore. In practice, this makes overriding `void` functions with non-`void` functions safer. * During static analysis, a function or setter declared using `=>` with return type `void` now allows the returned expression to have any type. For example, assuming the declaration `int x;`, it is now type correct to have `void f() => ++x;`. * A new function-type syntax has been added to the language. **Warning**: *In Dart 1.24, this feature is incomplete, and not stable in the Analyzer.* Intuitively, the type of a function can be constructed by textually replacing the function's name with `Function` in its declaration. For instance, the type of `void foo() {}` would be `void Function()`. The new syntax may be used wherever a type can be written. It is thus now possible to declare fields containing functions without needing to write typedefs: `void Function() x;`. The new function type has one restriction: it may not contain the old-style function-type syntax for its parameters. The following is thus illegal: `void Function(int f())`. `typedefs` have been updated to support this new syntax. Examples: ```dart typedef F = void Function(); // F is the name for a `void` callback. int Function(int) f; // A field `f` that contains an int->int function. class A { // The parameter `callback` is a function that takes a `T` and returns // `void`. void forEach(void Function(T) callback); } // The new function type supports generic arguments. typedef Invoker = T Function(T Function() callback); ``` ### Core library changes * `dart:async`, `dart:core`, `dart:io` * Adding to a closed sink, including `IOSink`, is no longer not allowed. In 1.24, violations are only reported (on stdout or stderr), but a future version of the Dart SDK will change this to throwing a `StateError`. * `dart:convert` * **BREAKING** Removed the deprecated `ChunkedConverter` class. * JSON maps are now typed as `Map` instead of `Map`. A JSON-map is not a `HashMap` or `LinkedHashMap` anymore (but just a `Map`). * `dart:io` * Added `Platform.localeName`, needed for accessing the locale on platforms that don't store it in an environment variable. * Added `ProcessInfo.currentRss` and `ProcessInfo.maxRss` for inspecting the Dart VM process current and peak resident set size. * Added `RawSynchronousSocket`, a basic synchronous socket implementation. * `dart:` web APIs have been updated to align with Chrome v50. This change includes **a large number of changes**, many of which are breaking. In some cases, new class names may conflict with names that exist in existing code. * `dart:html` * **REMOVED** classes: `Bluetooth`, `BluetoothDevice`, `BluetoothGattCharacteristic`, `BluetoothGattRemoteServer`, `BluetoothGattService`, `BluetoothUuid`, `CrossOriginConnectEvent`, `DefaultSessionStartEvent`, `DomSettableTokenList`, `MediaKeyError`, `PeriodicSyncEvent`, `PluginPlaceholderElement`, `ReadableStream`, `StashedMessagePort`, `SyncRegistration` * **REMOVED** members: * `texImage2DCanvas` was removed from `RenderingContext`. * `endClip` and `startClip` were removed from `Animation`. * `after` and `before` were removed from `CharacterData`, `ChildNode` and `Element`. * `keyLocation` was removed from `KeyboardEvent`. Use `location` instead. * `generateKeyRequest`, `keyAddedEvent`, `keyErrorEvent`, `keyMessageEvent`, `mediaGroup`, `needKeyEvent`, `onKeyAdded`, `onKeyError`, `onKeyMessage`, and `onNeedKey` were removed from `MediaElement`. * `getStorageUpdates` was removed from `Navigator` * `status` was removed from `PermissionStatus` * `getAvailability` was removed from `PreElement` * Other behavior changes: * URLs returned in CSS or html are formatted with quoted string. Like `url("http://google.com")` instead of `url(http://google.com)`. * Event timestamp property type changed from `int` to `num`. * Chrome introduced slight layout changes of UI objects. In addition many height/width dimensions are returned in subpixel values (`num` instead of whole numbers). * `setRangeText` with a `selectionMode` value of 'invalid' is no longer valid. Only "select", "start", "end", "preserve" are allowed. * `dart:svg` * A large number of additions and removals. Review your use of `dart:svg` carefully. * `dart:web_audio` * new method on `AudioContext` – `createIirFilter` returns a new class `IirFilterNode`. * `dart:web_gl` * new classes: `CompressedTextureAstc`, `ExtColorBufferFloat`, `ExtDisjointTimerQuery`, and `TimerQueryExt`. * `ExtFragDepth` added: `readPixels2` and `texImage2D2`. #### Strong Mode * Removed ad hoc `Future.then` inference in favor of using `FutureOr`. Prior to adding `FutureOr` to the language, the analyzer implented an ad hoc type inference for `Future.then` (and overrides) treating it as if the onValue callback was typed to return `FutureOr` for the purposes of inference. This ad hoc inference has been removed now that `FutureOr` has been added. Packages that implement `Future` must either type the `onValue` parameter to `.then` as returning `FutureOr`, or else must leave the type of the parameter entirely to allow inference to fill in the type. * During static analysis, a function or setter declared using `=>` with return type `void` now allows the returned expression to have any type. ### Tool Changes * Dartium Dartium is now based on Chrome v50. See *Core library changes* above for details on the changed APIs. * Pub * `pub build` and `pub serve` * Added support for the Dart Development Compiler. Unlike dart2js, this new compiler is modular, which allows pub to do incremental re-builds for `pub serve`, and potentially `pub build` in the future. In practice what that means is you can edit your Dart files, refresh in Chrome (or other supported browsers), and see your edits almost immediately. This is because pub is only recompiling your package, not all packages that you depend on. There is one caveat with the new compiler, which is that your package and your dependencies must all be strong mode clean. If you are getting an error compiling one of your dependencies, you will need to file bugs or send pull requests to get them strong mode clean. There are two ways of opting into the new compiler: * Use the new `--web-compiler` flag, which supports `dartdevc`, `dart2js` or `none` as options. This is the easiest way to try things out without changing the default. * Add config to your pubspec. There is a new `web` key which supports a single key called `compiler`. This is a map from mode names to compiler to use. For example, to default to dartdevc in debug mode you can add the following to your pubspec: ```yaml web: compiler: debug: dartdevc ``` You can also use the new compiler to run your tests in Chrome much more quickly than you can with dart2js. In order to do that, run `pub serve test --web-compiler=dartdevc`, and then run `pub run test -p chrome --pub-serve=8080`. * The `--no-dart2js` flag has been deprecated in favor of `--web-compiler=none`. * `pub build` will use a failing exit code if there are errors in any transformer. * `pub publish` * Added support for the UNLICENSE file. * Packages that depend on the Flutter SDK may be published. * `pub get` and `pub upgrade` * Don't dump a stack trace when a network error occurs while fetching packages. * dartfmt * Preserve type parameters in new generic function typedef syntax. * Add self-test validation to ensure formatter bugs do not cause user code to be lost. ### Infrastructure changes * As of this release, we'll show a warning when using the MIPS architecture. Unless we learn about any critical use of Dart on MIPS in the meantime, we're planning to deprecate support for MIPS starting with the next stable release. ## 1.23.0 - 2017-04-21 #### Strong Mode * Breaking change - it is now a strong mode error if a mixin causes a name conflict between two private members (field/getter/setter/method) from a different library. (SDK issue [28809](https://github.com/dart-lang/sdk/issues/28809)). lib1.dart: ```dart class A { int _x; } class B { int _x; } ``` lib2.dart: ```dart import 'lib1.dart'; class C extends A with B {} ``` ``` error • The private name _x, defined by B, conflicts with the same name defined by A at tmp/lib2.dart:3:24 • private_collision_in_mixin_application ``` * Breaking change - strong mode will prefer the expected type to infer generic types, functions, and methods (SDK issue [27586](https://github.com/dart-lang/sdk/issues/27586)). ```dart main() { List foo = /*infers: */['hello', 'world']; var bar = /*infers: */['hello', 'world']; } ``` * Strong mode inference error messages are improved (SDK issue [29108](https://github.com/dart-lang/sdk/issues/29108)). ```dart import 'dart:math'; test(Iterable/* fix is to add here */ values) { num n = values.fold(values.first as num, max); } ``` Now produces the error on the generic function "max": ``` Couldn't infer type parameter 'T'. Tried to infer 'dynamic' for 'T' which doesn't work: Function type declared as '(T, T) → T' used where '(num, dynamic) → num' is required. Consider passing explicit type argument(s) to the generic. ``` * Strong mode supports overriding fields, `@virtual` is no longer required (SDK issue [28120](https://github.com/dart-lang/sdk/issues/28120)). ```dart class C { int x = 42; } class D extends C { get x { print("x got called"); return super.x; } } main() { print(new D().x); } ``` * Strong mode down cast composite warnings are no longer issued by default. (SDK issue [28588](https://github.com/dart-lang/sdk/issues/28588)). ```dart void test() { List untyped = []; List typed = untyped; // No down cast composite warning } ``` To opt back into the warnings, add the following to the [.analysis_options](https://www.dartlang.org/guides/language/analysis-options) file for your project. ``` analyzer: errors: strong_mode_down_cast_composite: warning ``` ### Core library changes * `dart:core` * Added `Uri.isScheme` function to check the scheme of a URI. Example: `uri.isScheme("http")`. Ignores case when comparing. * Make `UriData.parse` validate its input better. If the data is base-64 encoded, the data is normalized wrt. alphabet and padding, and it contains invalid base-64 data, parsing fails. Also normalizes non-base-64 data. * `dart:io` * Added functions `File.lastAccessed`, `File.lastAccessedSync`, `File.setLastModified`, `File.setLastModifiedSync`, `File.setLastAccessed`, and `File.setLastAccessedSync`. * Added `{Stdin,Stdout}.supportsAnsiEscapes`. ### Dart VM * Calls to `print()` and `Stdout.write*()` now correctly print unicode characters to the console on Windows. Calls to `Stdout.add*()` behave as before. ### Tool changes * Analysis * `dartanalyzer` now follows the same rules as the analysis server to find an analysis options file, stopping when an analysis options file is found: * Search up the directory hierarchy looking for an analysis options file. * If analyzing a project referencing the [Flutter](https://flutter.io/) package, then use the [default Flutter analysis options](https://github.com/flutter/flutter/blob/master/packages/flutter/lib/analysis_options_user.yaml) found in `package:flutter`. * If in a Bazel workspace, then use the analysis options in `package:dart.analysis_options/default.yaml` if it exists. * Use the default analysis options rules. * In addition, specific to `dartanalyzer`: * an analysis options file can be specified on the command line via `--options` and that file will be used instead of searching for an analysis options file. * any analysis option specified on the command line (e.g. `--strong` or `--no-strong`) takes precedence over any corresponding value specified in the analysis options file. * Dartium, dart2js, and DDC * Imports to `dart:io` are allowed, but the imported library is not supported and will likely fail on most APIs at runtime. This change was made as a stopgap measure to make it easier to write libraries that share code between platforms (like package `http`). This might change again when configuration specific imports are supported. * Pub * Now sends telemetry data to `pub.dartlang.org` to allow better understanding of why a particular package is being accessed. * `pub publish` * Warns if a package imports a package that's not a dependency from within `lib/` or `bin/`, or a package that's not a dev dependency from within `benchmark/`, `example/`, `test/` or `tool/`. * No longer produces "UID too large" errors on OS X. All packages are now uploaded with the user and group names set to "pub". * No longer fails with a stack overflow when uploading a package that uses Git submodules. * `pub get` and `pub upgrade` * Produce more informative error messages if they're run directly in a package that uses Flutter. * Properly unlock SDK and path dependencies if they have a new version that's also valid according to the user's pubspec. * dartfmt * Support new generic function typedef syntax. * Make the precedence of cascades more visible. * Fix a couple of places where spurious newlines were inserted. * Correctly report unchanged formatting when reading from stdin. * Ensure space between `-` and `--`. Code that does this is pathological, but it technically meant dartfmt could change the semantics of the code. * Preserve a blank line between enum cases. * Other small formatting tweaks. ## 1.22.1 - 2017-02-22 Patch release, resolves two issues: * Dart VM crash: [Issue 28072](https://github.com/dart-lang/sdk/issues/28757) * Dart VM bug combining types, await, and deferred loading: [Issue 28678](https://github.com/dart-lang/sdk/issues/28678) ## 1.22.0 - 2017-02-14 ### Language * Breaking change: ['Generalized tear-offs'](https://github.com/gbracha/generalizedTearOffs/blob/master/proposal.md) are no longer supported, and will cause errors. We updated the language spec and added warnings in 1.21, and are now taking the last step to fully de-support them. They were previously only supported in the VM, and there are almost no known uses of them in the wild. * The `assert()` statement has been expanded to support an optional second `message` argument (SDK issue [27342](https://github.com/dart-lang/sdk/issues/27342)). The message is displayed if the assert fails. It can be any object, and it is accessible as `AssertionError.message`. It can be used to provide more user friendly exception outputs. As an example, the following assert: ```dart assert(configFile != null, "Tool config missing. Please see https://goo.gl/k8iAi for details."); ``` would produce the following exception output: ``` Unhandled exception: 'file:///Users/mit/tmp/tool/bin/main.dart': Failed assertion: line 9 pos 10: 'configFile != null': Tool config missing. Please see https://goo.gl/k8iAi for details. #0 _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:33) #1 _AssertionError._throwNew (dart:core-patch/errors_patch.dart:29) #2 main (file:///Users/mit/tmp/tool/bin/main.dart:9:10) ``` * The `Null` type has been moved to the bottom of the type hierarchy. As such, it is considered a subtype of every other type. The `null` *literal* was always treated as a bottom type. Now the named class `Null` is too: ```dart const empty = []; String concatenate(List parts) => parts.join(); int sum(List numbers) => numbers.fold(0, (sum, n) => sum + n); concatenate(empty); // OK. sum(empty); // OK. ``` * Introduce `covariant` modifier on parameters. It indicates that the parameter (and the corresponding parameter in any method that overrides it) has looser override rules. In strong mode, these require a runtime type check to maintain soundness, but enable an architectural pattern that is useful in some code. It lets you specialize a family of classes together, like so: ```dart abstract class Predator { void chaseAndEat(covariant Prey p); } abstract class Prey {} class Mouse extends Prey {} class Seal extends Prey {} class Cat extends Predator { void chaseAndEat(Mouse m) => ... } class Orca extends Predator { void chaseAndEat(Seal s) => ... } ``` This isn't statically safe, because you could do: ```dart Predator predator = new Cat(); // Upcast. predator.chaseAndEat(new Seal()); // Cats can't eat seals! ``` To preserve soundness in strong mode, in the body of a method that uses a covariant override (here, `Cat.chaseAndEat()`), the compiler automatically inserts a check that the parameter is of the expected type. So the compiler gives you something like: ```dart class Cat extends Predator { void chaseAndEat(o) { var m = o as Mouse; ... } } ``` Spec mode allows this unsound behavior on all parameters, even though users rarely rely on it. Strong mode disallowed it initially. Now, strong mode lets you opt into this behavior in the places where you do want it by using this modifier. Outside of strong mode, the modifier is ignored. * Change instantiate-to-bounds rules for generic type parameters when running in strong mode. If you leave off the type parameters from a generic type, we need to decide what to fill them in with. Dart 1.0 says just use `dynamic`, but that isn't sound: ```dart class Abser { void absThis(T n) { n.abs(); } } var a = new Abser(); // Abser. a.absThis("not a num"); ``` We want the body of `absThis()` to be able to safely assume `n` is at least a `num` -- that's why there's a constraint on T, after all. Implicitly using `dynamic` as the type parameter in this example breaks that. Instead, strong mode uses the bound. In the above example, it fills it in with `num`, and then the second line where a string is passed becomes a static error. However, there are some cases where it is hard to figure out what that default bound should be: ```dart class RuhRoh> {} ``` Strong mode's initial behavior sometimes produced surprising, unintended results. For 1.22, we take a simpler approach and then report an error if a good default type argument can't be found. ### Core libraries * Define `FutureOr` for code that works with either a future or an immediate value of some type. For example, say you do a lot of text manipulation, and you want a handy function to chain a bunch of them: ```dart typedef String StringSwizzler(String input); String swizzle(String input, List swizzlers) { var result = input; for (var swizzler in swizzlers) { result = swizzler(result); } return result; } ``` This works fine: ```dart main() { var result = swizzle("input", [ (s) => s.toUpperCase(), (s) => () => s * 2) ]); print(result); // "INPUTINPUT". } ``` Later, you realize you'd also like to support swizzlers that are asynchronous (maybe they look up synonyms for words online). You could make your API strictly asynchronous, but then users of simple synchronous swizzlers have to manually wrap the return value in a `Future.value()`. Ideally, your `swizzle()` function would be "polymorphic over asynchrony". It would allow both synchronous and asynchronous swizzlers. Because `await` accepts immediate values, it is easy to implement this dynamically: ```dart Future swizzle(String input, List swizzlers) async { var result = input; for (var swizzler in swizzlers) { result = await swizzler(result); } return result; } main() async { var result = swizzle("input", [ (s) => s.toUpperCase(), (s) => new Future.delayed(new Duration(milliseconds: 40), () => s * 2) ]); print(await result); } ``` What should the declared return type on StringSwizzler be? In the past, you had to use `dynamic` or `Object`, but that doesn't tell the user much. Now, you can do: ```dart typedef FutureOr StringSwizzler(String input); ``` Like the name implies, `FutureOr` is a union type. It can be a `String` or a `Future`, but not anything else. In this case, that's not super useful beyond just stating a more precise type for readers of the code. It does give you a little better error checking in code that uses the result of that. `FutureOr` becomes really important in *generic* methods like `Future.then()`. In those cases, having the type system understand this magical union type helps type inference figure out the type argument of `then()` based on the closure you pass it. Previously, strong mode had hard-coded rules for handling `Future.then()` specifically. `FutureOr` exposes that functionality so third-party APIs can take advantage of it too. ### Tool changes * Dart2Js * Remove support for (long-time deprecated) mixin typedefs. * Pub * Avoid using a barback asset server for executables unless they actually use transformers. This makes precompilation substantially faster, produces better error messages when precompilation fails, and allows globally-activated executables to consistently use the `Isolate.resolvePackageUri()` API. * On Linux systems, always ignore packages' original file owners and permissions when extracting those packages. This was already the default under most circumstances. * Properly close the standard input stream of child processes started using `pub run`. * Handle parse errors from the package cache more gracefully. A package whose pubspec can't be parsed will now be ignored by `pub get --offline` and deleted by `pub cache repair`. * Make `pub run` run executables in spawned isolates. This lets them handle signals and use standard IO reliably. * Fix source-maps produced by dart2js when running in `pub serve`: URL references to assets from packages match the location where `pub serve` serves them (`packages/package_name/` instead of `../packages/package_name/`). ### Infrastructure changes * The SDK now uses GN rather than gyp to generate its build files, which will now be exclusively ninja flavored. Documentation can be found on our [wiki](https://github.com/dart-lang/sdk/wiki/Building-with-GN). Also see the help message of `tools/gn.py`. This change is in response to the deprecation of gyp. Build file generation with gyp will continue to be available in this release by setting the environment variable `DART_USE_GYP` before running `gclient sync` or `gclient runhooks`, but this will be removed in a future release. ## 1.21.1 - 2017-01-13 Patch release, resolves one issue: * Dart VM: Snapshots of generic functions fail. [Issue 28072](https://github.com/dart-lang/sdk/issues/28072) ## 1.21.0 - 2016-12-07 ### Language * Support generic method syntax. Type arguments are not available at runtime. For details, check the [informal specification](https://gist.github.com/eernstg/4353d7b4f669745bed3a5423e04a453c). * Support access to initializing formals, e.g., the use of `x` to initialize `y` in `class C { var x, y; C(this.x): y = x; }`. Please check the [informal specification](https://gist.github.com/eernstg/cff159be9e34d5ea295d8c24b1a3e594) for details. * Don't warn about switch case fallthrough if the case ends in a `rethrow` statement. (SDK issue [27650](https://github.com/dart-lang/sdk/issues/27650)) * Also don't warn if the entire switch case is wrapped in braces - as long as the block ends with a `break`, `continue`, `rethrow`, `return` or `throw`. * Allow `=` as well as `:` as separator for named parameter default values. ```dart enableFlags({bool hidden: false}) { … } ``` can now be replaced by ```dart enableFlags({bool hidden = false}) { … } ``` (SDK issue [27559](https://github.com/dart-lang/sdk/issues/27559)) ### Core library changes * `dart:core`: `Set.difference` now takes a `Set` as argument. (SDK issue [27573](https://github.com/dart-lang/sdk/issues/27573)) * `dart:developer` * Added `Service` class. * Allows inspecting and controlling the VM service protocol HTTP server. * Provides an API to access the ID of an `Isolate`. ### Tool changes * Dart Dev Compiler * Support calls to `loadLibrary()` on deferred libraries. Deferred libraries are still loaded eagerly. (SDK issue [27343](https://github.com/dart-lang/sdk/issues/27343)) ## 1.20.1 - 2016-10-13 Patch release, resolves one issue: * Dartium: Fixes a bug that caused crashes. No issue filed. ### Strong Mode * It is no longer a warning when casting from dynamic to a composite type (SDK issue [27766](https://github.com/dart-lang/sdk/issues/27766)). ```dart main() { dynamic obj = [1, 2, 3]; // This is now allowed without a warning. List list = obj; } ``` ## 1.20.0 - 2016-10-11 ### Dart VM * We have improved the way that the VM locates the native code library for a native extension (e.g. `dart-ext:` import). We have updated this [article on native extensions](https://www.dartlang.org/articles/dart-vm/native-extensions) to reflect the VM's improved behavior. * Linux builds of the VM will now use the `tcmalloc` library for memory allocation. This has the advantages of better debugging and profiling support and faster small allocations, with the cost of slightly larger initial memory footprint, and slightly slower large allocations. * We have improved the way the VM searches for trusted root certificates for secure socket connections on Linux. First, the VM will look for trusted root certificates in standard locations on the file system (`/etc/pki/tls/certs/ca-bundle.crt` followed by `/etc/ssl/certs`), and only if these do not exist will it fall back on the builtin trusted root certificates. This behavior can be overridden on Linux with the new flags `--root-certs-file` and `--root-certs-cache`. The former is the path to a file containing the trusted root certificates, and the latter is the path to a directory containing root certificate files hashed using `c_rehash`. * The VM now throws a catchable `Error` when method compilation fails. This allows easier debugging of syntax errors, especially when testing. (SDK issue [23684](https://github.com/dart-lang/sdk/issues/23684)) ### Core library changes * `dart:core`: Remove deprecated `Resource` class. Use the class in `package:resource` instead. * `dart:async` * `Future.wait` now catches synchronous errors and returns them in the returned Future. (SDK issue [27249](https://github.com/dart-lang/sdk/issues/27249)) * More aggressively returns a `Future` on `Stream.cancel` operations. Discourages to return `null` from `cancel`. (SDK issue [26777](https://github.com/dart-lang/sdk/issues/26777)) * Fixes a few bugs where the cancel future wasn't passed through transformations. * `dart:io` * Added `WebSocket.addUtf8Text` to allow sending a pre-encoded text message without a round-trip UTF-8 conversion. (SDK issue [27129](https://github.com/dart-lang/sdk/issues/27129)) ### Strong Mode * Breaking change - it is an error if a generic type parameter cannot be inferred (SDK issue [26992](https://github.com/dart-lang/sdk/issues/26992)). ```dart class Cup { Cup(T t); } main() { // Error because: // - if we choose Cup it is not assignable to `cOfInt`, // - if we choose Cup then `n` is not assignable to int. num n; C cOfInt = new C(n); } ``` * New feature - use `@checked` to override a method and tighten a parameter type (SDK issue [25578](https://github.com/dart-lang/sdk/issues/25578)). ```dart import 'package:meta/meta.dart' show checked; class View { addChild(View v) {} } class MyView extends View { // this override is legal, it will check at runtime if we actually // got a MyView. addChild(@checked MyView v) {} } main() { dynamic mv = new MyView(); mv.addChild(new View()); // runtime error } ``` * New feature - use `@virtual` to allow field overrides in strong mode (SDK issue [27384](https://github.com/dart-lang/sdk/issues/27384)). ```dart import 'package:meta/meta.dart' show virtual; class Base { @virtual int x; } class Derived extends Base { int x; // Expose the hidden storage slot: int get superX => super.x; set superX(int v) { super.x = v; } } ``` * Breaking change - infer list and map literals from the context type as well as their values, consistent with generic methods and instance creation (SDK issue [27151](https://github.com/dart-lang/sdk/issues/27151)). ```dart import 'dart:async'; main() async { var b = new Future.value(new B()); var c = new Future.value(new C()); var/*infer List>*/ list = [b, c]; var/*infer List*/ result = await Future.wait(list); } class A {} class B extends A {} class C extends A {} ``` ### Tool changes * `dartfmt` - upgraded to v0.2.10 * Don't crash on annotations before parameters with trailing commas. * Always split enum declarations if they end in a trailing comma. * Add `--set-exit-if-changed` to set the exit code on a change. * Pub * Pub no longer generates a `packages/` directory by default. Instead, it generates a `.packages` file, called a package spec. To generate a `packages/` directory in addition to the package spec, use the `--packages-dir` flag with `pub get`, `pub upgrade`, and `pub downgrade`. See the [Good-bye symlinks](http://news.dartlang.org/2016/10/good-bye-symlinks.html) article for details. ## 1.19.1 - 2016-09-08 Patch release, resolves one issue: * Dartdoc: Fixes a bug that prevented generation of docs. (Dartdoc issue [1233](https://github.com/dart-lang/dartdoc/issues/1233)) ## 1.19.0 - 2016-08-26 ### Language changes * The language now allows a trailing comma after the last argument of a call and the last parameter of a function declaration. This can make long argument or parameter lists easier to maintain, as commas can be left as-is when reordering lines. For details, see SDK issue [26644](https://github.com/dart-lang/sdk/issues/26644). ### Tool Changes * `dartfmt` - upgraded to v0.2.9+1 * Support trailing commas in argument and parameter lists. * Gracefully handle read-only files. * About a dozen other bug fixes. * Pub * Added a `--no-packages-dir` flag to `pub get`, `pub upgrade`, and `pub downgrade`. When this flag is passed, pub will not generate a `packages/` directory, and will remove that directory and any symlinks to it if they exist. Note that this replaces the unsupported `--no-package-symlinks` flag. * Added the ability for packages to declare a constraint on the [Flutter][] SDK: ```yaml environment: flutter: ^0.1.2 sdk: >=1.19.0 <2.0.0 ``` A Flutter constraint will only be satisfiable when pub is running in the context of the `flutter` executable, and when the Flutter SDK version matches the constraint. * Added `sdk` as a new package source that fetches packages from a hard-coded SDK. Currently only the `flutter` SDK is supported: ```yaml dependencies: flutter_driver: sdk: flutter version: ^0.0.1 ``` A Flutter `sdk` dependency will only be satisfiable when pub is running in the context of the `flutter` executable, and when the Flutter SDK contains a package with the given name whose version matches the constraint. * `tar` files on Linux are now created with `0` as the user and group IDs. This fixes a crash when publishing packages while using Active Directory. * Fixed a bug where packages from a hosted HTTP URL were considered the same as packages from an otherwise-identical HTTPS URL. * Fixed timer formatting for timers that lasted longer than a minute. * Eliminate some false negatives when determining whether global executables are on the user's executable path. * `dart2js` * `dart2dart` (aka `dart2js --output-type=dart`) has been removed (this was deprecated in Dart 1.11). [Flutter]: https://flutter.io/ ### Dart VM * The dependency on BoringSSL has been rolled forward. Going forward, builds of the Dart VM including secure sockets will require a compiler with C++11 support. For details, see the [Building wiki page](https://github.com/dart-lang/sdk/wiki/Building). ### Strong Mode * New feature - an option to disable implicit casts (SDK issue [26583](https://github.com/dart-lang/sdk/issues/26583)), see the [documentation](https://github.com/dart-lang/dev_compiler/blob/master/doc/STATIC_SAFETY.md#disable-implicit-casts) for usage instructions and examples. * New feature - an option to disable implicit dynamic (SDK issue [25573](https://github.com/dart-lang/sdk/issues/25573)), see the [documentation](https://github.com/dart-lang/dev_compiler/blob/master/doc/STATIC_SAFETY.md#disable-implicit-dynamic) for usage instructions and examples. * Breaking change - infer generic type arguments from the constructor invocation arguments (SDK issue [25220](https://github.com/dart-lang/sdk/issues/25220)). ```dart var map = new Map(); // infer: Map var otherMap = new Map.from(map); ``` * Breaking change - infer local function return type (SDK issue [26414](https://github.com/dart-lang/sdk/issues/26414)). ```dart void main() { // infer: return type is int f() { return 40; } int y = f() + 2; // type checks print(y); } ``` * Breaking change - allow type promotion from a generic type parameter (SDK issue [26414](https://github.com/dart-lang/sdk/issues/26965)). ```dart void fn/**/(/*=T*/ object) { if (object is String) { // Treat `object` as `String` inside this block. // But it will require a cast to pass it to something that expects `T`. print(object.substring(1)); } } ``` * Breaking change - smarter inference for Future.then (SDK issue [25944](https://github.com/dart-lang/sdk/issues/25944)). Previous workarounds that use async/await or `.then/*>*/` should no longer be necessary. ```dart // This will now infer correctly. Future> t2 = f.then((_) => [3]); // This infers too. Future t2 = f.then((_) => new Future.value(42)); ``` * Breaking change - smarter inference for async functions (SDK issue [25322](https://github.com/dart-lang/sdk/issues/25322)). ```dart void test() async { List x = await [4]; // was previously inferred List y = await new Future.value([4]); // now inferred too } ``` * Breaking change - sideways casts are no longer allowed (SDK issue [26120](https://github.com/dart-lang/sdk/issues/26120)). ## 1.18.1 - 2016-08-02 Patch release, resolves two issues and improves performance: * Debugger: Fixes a bug that crashes the VM (SDK issue [26941](https://github.com/dart-lang/sdk/issues/26941)) * VM: Fixes an optimizer bug involving closures, try, and await (SDK issue [26948](https://github.com/dart-lang/sdk/issues/26948)) * Dart2js: Speeds up generated code on Firefox (https://codereview.chromium.org/2180533002) ## 1.18.0 - 2016-07-27 ### Core library changes * `dart:core` * Improved performance when parsing some common URIs. * Fixed bug in `Uri.resolve` (SDK issue [26804](https://github.com/dart-lang/sdk/issues/26804)). * `dart:io` * Adds file locking modes `FileLock.BLOCKING_SHARED` and `FileLock.BLOCKING_EXCLUSIVE`. ## 1.17.1 - 2016-06-10 Patch release, resolves two issues: * VM: Fixes a bug that caused crashes in async functions. (SDK issue [26668](https://github.com/dart-lang/sdk/issues/26668)) * VM: Fixes a bug that caused garbage collection of reachable weak properties. (https://codereview.chromium.org/2041413005) ## 1.17.0 - 2016-06-08 ### Core library changes * `dart:convert` * Deprecate `ChunkedConverter` which was erroneously added in 1.16. * `dart:core` * `Uri.replace` supports iterables as values for the query parameters. * `Uri.parseIPv6Address` returns a `Uint8List`. * `dart:io` * Added `NetworkInterface.listSupported`, which is `true` when `NetworkInterface.list` is supported, and `false` otherwise. Currently, `NetworkInterface.list` is not supported on Android. ### Tool Changes * Pub * TAR files created while publishing a package on Mac OS and Linux now use a more portable format. * Errors caused by invalid arguments now print the full usage information for the command. * SDK constraints for dependency overrides are no longer considered when determining the total SDK constraint for a lockfile. * A bug has been fixed in which a lockfile was considered up-to-date when it actually wasn't. * A bug has been fixed in which `pub get --offline` would crash when a prerelease version was selected. * Dartium and content shell * Debugging Dart code inside iframes improved, was broken. ## 1.16.1 - 2016-05-24 Patch release, resolves one issue: * VM: Fixes a bug that caused intermittent hangs on Windows. (SDK issue [26400](https://github.com/dart-lang/sdk/issues/26400)) ## 1.16.0 - 2016-04-26 ### Core library changes * `dart:convert` * Added `BASE64URL` codec and corresponding `Base64Codec.urlSafe` constructor. * Introduce `ChunkedConverter` and deprecate chunked methods on `Converter`. * `dart:html` There have been a number of **BREAKING** changes to align APIs with recent changes in Chrome. These include: * Chrome's `ShadowRoot` interface no longer has the methods `getElementById`, `getElementsByClassName`, and `getElementsByTagName`, e.g., ```dart elem.shadowRoot.getElementsByClassName('clazz') ``` should become: ```dart elem.shadowRoot.querySelectorAll('.clazz') ``` * The `clipboardData` property has been removed from `KeyEvent` and `Event`. It has been moved to the new `ClipboardEvent` class, which is now used by `copy`, `cut`, and `paste` events. * The `layer` property has been removed from `KeyEvent` and `UIEvent`. It has been moved to `MouseEvent`. * The `Point get page` property has been removed from `UIEvent`. It still exists on `MouseEvent` and `Touch`. There have also been a number of other additions and removals to `dart:html`, `dart:indexed_db`, `dart:svg`, `dart:web_audio`, and `dart:web_gl` that correspond to changes to Chrome APIs between v39 and v45. Many of the breaking changes represent APIs that would have caused runtime exceptions when compiled to Javascript and run on recent Chrome releases. * `dart:io` * Added `SecurityContext.alpnSupported`, which is true if a platform supports ALPN, and false otherwise. ### JavaScript interop For performance reasons, a potentially **BREAKING** change was added for libraries that use JS interop. Any Dart file that uses `@JS` annotations on declarations (top-level functions, classes or class members) to interop with JavaScript code will require that the file have the annotation `@JS()` on a library directive. ```dart @JS() library my_library; ``` The analyzer will enforce this by generating the error: The `@JS()` annotation can only be used if it is also declared on the library directive. If part file uses the `@JS()` annotation, the library that uses the part should have the `@JS()` annotation e.g., ```dart // library_1.dart @JS() library library_1; import 'package:js/js.dart'; part 'part_1.dart'; ``` ```dart // part_1.dart part of library_1; @JS("frameworkStabilizers") external List get frameworkStabilizers; ``` If your library already has a JS module e.g., ```dart @JS('array.utils') library my_library; ``` Then your library will work without any additional changes. ### Analyzer * Static checking of `for in` statements. These will now produce static warnings: ```dart // Not Iterable. for (var i in 1234) { ... } // String cannot be assigned to int. for (int n in ["a", "b"]) { ... } ``` ### Tool Changes * Pub * `pub serve` now provides caching headers that should improve the performance of requesting large files multiple times. * Both `pub get` and `pub upgrade` now have a `--no-precompile` flag that disables precompilation of executables and transformed dependencies. * `pub publish` now resolves symlinks when publishing from a Git repository. This matches the behavior it always had when publishing a package that wasn't in a Git repository. * Dart Dev Compiler * The **experimental** `dartdevc` executable has been added to the SDK. * It will help early adopters validate the implementation and provide feedback. `dartdevc` **is not** yet ready for production usage. * Read more about the Dart Dev Compiler [here][dartdevc]. [dartdevc]: https://github.com/dart-lang/dev_compiler ## 1.15.0 - 2016-03-09 ### Core library changes * `dart:async` * Made `StreamView` class a `const` class. * `dart:core` * Added `Uri.queryParametersAll` to handle multiple query parameters with the same name. * `dart:io` * Added `SecurityContext.usePrivateKeyBytes`, `SecurityContext.useCertificateChainBytes`, `SecurityContext.setTrustedCertificatesBytes`, and `SecurityContext.setClientAuthoritiesBytes`. * **Breaking** The named `directory` argument of `SecurityContext.setTrustedCertificates` has been removed. * Added support to `SecurityContext` for PKCS12 certificate and key containers. * All calls in `SecurityContext` that accept certificate data now accept an optional named parameter `password`, similar to `SecurityContext.usePrivateKeyBytes`, for use as the password for PKCS12 data. ### Tool changes * Dartium and content shell * The Chrome-based tools that ship as part of the Dart SDK – Dartium and content shell – are now based on Chrome version 45 (instead of Chrome 39). * Dart browser libraries (`dart:html`, `dart:svg`, etc) *have not* been updated. * These are still based on Chrome 39. * These APIs will be updated in a future release. * Note that there are experimental APIs which have changed in the underlying browser, and will not work with the older libraries. For example, `Element.animate`. * `dartfmt` - upgraded to v0.2.4 * Better handling for long collections with comments. * Always put member metadata annotations on their own line. * Indent functions in named argument lists with non-functions. * Force the parameter list to split if a split occurs inside a function-typed parameter. * Don't force a split for before a single named argument if the argument itself splits. ### Service protocol changes * Fixed a documentation bug where the field `extensionRPCs` in `Isolate` was not marked optional. ### Experimental language features * Added support for [configuration-specific imports](https://github.com/munificent/dep-interface-libraries/blob/master/Proposal.md). On the VM and `dart2js`, they can be enabled with `--conditional-directives`. The analyzer requires additional configuration: ```yaml analyzer: language: enableConditionalDirectives: true ``` Read about [configuring the analyzer] for more details. [configuring the analyzer]: https://github.com/dart-lang/sdk/tree/master/pkg/analyzer#configuring-the-analyzer ## 1.14.2 - 2016-02-10 Patch release, resolves three issues: * VM: Fixed a code generation bug on x64. (SDK commit [834b3f02](https://github.com/dart-lang/sdk/commit/834b3f02b6ab740a213fd808e6c6f3269bed80e5)) * `dart:io`: Fixed EOF detection when reading some special device files. (SDK issue [25596](https://github.com/dart-lang/sdk/issues/25596)) * Pub: Fixed an error using hosted dependencies in SDK version 1.14. (Pub issue [1386](https://github.com/dart-lang/pub/issues/1386)) ## 1.14.1 - 2016-02-04 Patch release, resolves one issue: * Debugger: Fixes a VM crash when a debugger attempts to set a break point during isolate initialization. (SDK issue [25618](https://github.com/dart-lang/sdk/issues/25618)) ## 1.14.0 - 2016-01-28 ### Core library changes * `dart:async` * Added `Future.any` static method. * Added `Stream.fromFutures` constructor. * `dart:convert` * `Base64Decoder.convert` now takes optional `start` and `end` parameters. * `dart:core` * Added `current` getter to `StackTrace` class. * `Uri` class added support for data URIs * Added two new constructors: `dataFromBytes` and `dataFromString`. * Added a `data` getter for `data:` URIs with a new `UriData` class for the return type. * Added `growable` parameter to `List.filled` constructor. * Added microsecond support to `DateTime`: `DateTime.microsecond`, `DateTime.microsecondsSinceEpoch`, and `new DateTime.fromMicrosecondsSinceEpoch`. * `dart:math` * `Random` added a `secure` constructor returning a cryptographically secure random generator which reads from the entropy source provided by the embedder for every generated random value. * `dart:io` * `Platform` added a static `isIOS` getter and `Platform.operatingSystem` may now return `ios`. * `Platform` added a static `packageConfig` getter. * Added support for WebSocket compression as standardized in RFC 7692. * Compression is enabled by default for all WebSocket connections. * The optionally named parameter `compression` on the methods `WebSocket.connect`, `WebSocket.fromUpgradedSocket`, and `WebSocketTransformer.upgrade` and the `WebSocketTransformer` constructor can be used to modify or disable compression using the new `CompressionOptions` class. * `dart:isolate` * Added **_experimental_** support for [Package Resolution Configuration]. * Added `packageConfig` and `packageRoot` instance getters to `Isolate`. * Added a `resolvePackageUri` method to `Isolate`. * Added named arguments `packageConfig` and `automaticPackageResolution` to the `Isolate.spawnUri` constructor. [Package Resolution Configuration]: https://github.com/dart-lang/dart_enhancement_proposals/blob/master/Accepted/0005%20-%20Package%20Specification/DEP-pkgspec.md ### Tool changes * `dartfmt` * Better line splitting in a variety of cases. * Other optimizations and bug fixes. * Pub * **Breaking:** Pub now eagerly emits an error when a pubspec's "name" field is not a valid Dart identifier. Since packages with non-identifier names were never allowed to be published, and some of them already caused crashes when being written to a `.packages` file, this is unlikely to break many people in practice. * **Breaking:** Support for `barback` versions prior to 0.15.0 (released July 1) has been dropped. Pub will no longer install these older barback versions. * `pub serve` now GZIPs the assets it serves to make load times more similar to real-world use-cases. * `pub deps` now supports a `--no-dev` flag, which causes it to emit the dependency tree as it would be if no `dev_dependencies` were in use. This makes it easier to see your package's dependency footprint as your users will experience it. * `pub global run` now detects when a global executable's SDK constraint is no longer met and errors out, rather than trying to run the executable anyway. * Pub commands that check whether the lockfile is up-to-date (`pub run`, `pub deps`, `pub serve`, and `pub build`) now do additional verification. They ensure that any path dependencies' pubspecs haven't been changed, and they ensure that the current SDK version is compatible with all dependencies. * Fixed a crashing bug when using `pub global run` on a global script that didn't exist. * Fixed a crashing bug when a pubspec contains a dependency without a source declared. ## 1.13.2 - 2016-01-06 Patch release, resolves one issue: * dart2js: Stack traces are not captured correctly (SDK issue [25235] (https://github.com/dart-lang/sdk/issues/25235)) ## 1.13.1 - 2015-12-17 Patch release, resolves three issues: * VM type propagation fix: Resolves a potential crash in the Dart VM (SDK commit [dff13be] (https://github.com/dart-lang/sdk/commit/dff13bef8de104d33b04820136da2d80f3c835d7)) * dart2js crash fix: Resolves a crash in pkg/js and dart2js (SDK issue [24974] (https://github.com/dart-lang/sdk/issues/24974)) * Pub get crash on ARM: Fixes a crash triggered when running 'pub get' on ARM processors such as those on a Raspberry Pi (SDK issue [24855] (https://github.com/dart-lang/sdk/issues/24855)) ## 1.13.0 - 2015-11-18 ### Core library changes * `dart:async` * `StreamController` added getters for `onListen`, `onPause`, and `onResume` with the corresponding new `typedef void ControllerCallback()`. * `StreamController` added a getter for `onCancel` with the corresponding new `typedef ControllerCancelCallback()`; * `StreamTransformer` instances created with `fromHandlers` with no `handleError` callback now forward stack traces along with errors to the resulting streams. * `dart:convert` * Added support for Base-64 encoding and decoding. * Added new classes `Base64Codec`, `Base64Encoder`, and `Base64Decoder`. * Added new top-level `const Base64Codec BASE64`. * `dart:core` * `Uri` added `removeFragment` method. * `String.allMatches` (implementing `Pattern.allMatches`) is now lazy, as all `allMatches` implementations are intended to be. * `Resource` is deprecated, and will be removed in a future release. * `dart:developer` * Added `Timeline` class for interacting with Observatory's timeline feature. * Added `ServiceExtensionHandler`, `ServiceExtensionResponse`, and `registerExtension` which enable developers to provide their own VM service protocol extensions. * `dart:html`, `dart:indexed_db`, `dart:svg`, `dart:web_audio`, `dart:web_gl`, `dart:web_sql` * The return type of some APIs changed from `double` to `num`. Dartium is now using JS interop for most operations. JS does not distinguish between numeric types, and will return a number as an int if it fits in an int. This will mostly cause an error if you assign to something typed `double` in checked mode. You may need to insert a `toDouble()` call or accept `num`. Examples of APIs that are affected include `Element.getBoundingClientRect` and `TextMetrics.width`. * `dart:io` * **Breaking:** Secure networking has changed, replacing the NSS library with the BoringSSL library. `SecureSocket`, `SecureServerSocket`, `RawSecureSocket`,`RawSecureServerSocket`, `HttpClient`, and `HttpServer` now all use a `SecurityContext` object which contains the certificates and keys used for secure TLS (SSL) networking. This is a breaking change for server applications and for some client applications. Certificates and keys are loaded into the `SecurityContext` from PEM files, instead of from an NSS certificate database. Information about how to change applications that use secure networking is at https://www.dartlang.org/server/tls-ssl.html * `HttpClient` no longer sends URI fragments in the request. This is not allowed by the HTTP protocol. The `HttpServer` still gracefully receives fragments, but discards them before delivering the request. * To allow connections to be accepted on the same port across different isolates, set the `shared` argument to `true` when creating server socket and `HttpServer` instances. * The deprecated `ServerSocketReference` and `RawServerSocketReference` classes have been removed. * The corresponding `reference` properties on `ServerSocket` and `RawServerSocket` have been removed. * `dart:isolate` * `spawnUri` added an `environment` named argument. ### Tool changes * `dart2js` and Dartium now support improved Javascript Interoperability via the [js package](https://pub.dartlang.org/packages/js). * `docgen` and `dartdocgen` no longer ship in the SDK. The `docgen` sources have been removed from the repository. * This is the last release to ship the VM's "legacy debug protocol". We intend to remove the legacy debug protocol in Dart VM 1.14. * The VM's Service Protocol has been updated to version 3.0 to take care of a number of issues uncovered by the first few non-observatory clients. This is a potentially breaking change for clients. * Dartium has been substantially changed. Rather than using C++ calls into Chromium internals for DOM operations it now uses JS interop. The DOM objects in `dart:html` and related libraries now wrap a JavaScript object and delegate operations to it. This should be mostly transparent to users. However, performance and memory characteristics may be different from previous versions. There may be some changes in which DOM objects are wrapped as Dart objects. For example, if you get a reference to a Window object, even through JS interop, you will always see it as a Dart Window, even when used cross-frame. We expect the change to using JS interop will make it much simpler to update to new Chrome versions. ## 1.12.2 - 2015-10-21 ### Core library changes * `dart:io` * A memory leak in creation of Process objects is fixed. ## 1.12.1 - 2015-09-08 ### Tool changes * Pub * Pub will now respect `.gitignore` when validating a package before it's published. For example, if a `LICENSE` file exists but is ignored, that is now an error. * If the package is in a subdirectory of a Git repository and the entire subdirectory is ignored with `.gitignore`, pub will act as though nothing was ignored instead of uploading an empty package. * The heuristics for determining when `pub get` needs to be run before various commands have been improved. There should no longer be false positives when non-dependency sections of the pubspec have been modified. ## 1.12.0 - 2015-08-31 ### Language changes * Null-aware operators * `??`: if null operator. `expr1 ?? expr2` evaluates to `expr1` if not `null`, otherwise `expr2`. * `??=`: null-aware assignment. `v ??= expr` causes `v` to be assigned `expr` only if `v` is `null`. * `x?.p`: null-aware access. `x?.p` evaluates to `x.p` if `x` is not `null`, otherwise evaluates to `null`. * `x?.m()`: null-aware method invocation. `x?.m()` invokes `m` only if `x` is not `null`. ### Core library changes * `dart:async` * `StreamController` added setters for the `onListen`, `onPause`, `onResume` and `onCancel` callbacks. * `dart:convert` * `LineSplitter` added a `split` static method returning an `Iterable`. * `dart:core` * `Uri` class now perform path normalization when a URI is created. This removes most `..` and `.` sequences from the URI path. Purely relative paths (no scheme or authority) are allowed to retain some leading "dot" segments. Also added `hasAbsolutePath`, `hasEmptyPath`, and `hasScheme` properties. * `dart:developer` * New `log` function to transmit logging events to Observatory. * `dart:html` * `NodeTreeSanitizer` added the `const trusted` field. It can be used instead of defining a `NullTreeSanitizer` class when calling `setInnerHtml` or other methods that create DOM from text. It is also more efficient, skipping the creation of a `DocumentFragment`. * `dart:io` * Added two new file modes, `WRITE_ONLY` and `WRITE_ONLY_APPEND` for opening a file write only. [eaeecf2](https://github.com/dart-lang/sdk/commit/eaeecf2ed13ba6c7fbfd653c3c592974a7120960) * Change stdout/stderr to binary mode on Windows. [4205b29](https://github.com/dart-lang/sdk/commit/4205b2997e01f2cea8e2f44c6f46ed6259ab7277) * `dart:isolate` * Added `onError`, `onExit` and `errorsAreFatal` parameters to `Isolate.spawnUri`. * `dart:mirrors` * `InstanceMirror.delegate` moved up to `ObjectMirror`. * Fix InstanceMirror.getField optimization when the selector is an operator. * Fix reflective NoSuchMethodErrors to match their non-reflective counterparts when due to argument mismatches. (VM only) ### Tool changes * Documentation tools * `dartdoc` is now the default tool to generate static HTML for API docs. [Learn more](https://pub.dartlang.org/packages/dartdoc). * `docgen` and `dartdocgen` have been deprecated. Currently plan is to remove them in 1.13. * Formatter (`dartfmt`) * Over 50 bugs fixed. * Optimized line splitter is much faster and produces better output on complex code. * Observatory * Allocation profiling. * New feature to display output from logging. * Heap snapshot analysis works for 64-bit VMs. * Improved ability to inspect typed data, regex and compiled code. * Ability to break on all or uncaught exceptions from Observatory's debugger. * Ability to set closure-specific breakpoints. * 'anext' - step past await/yield. * Preserve when a variable has been expanded/unexpanded in the debugger. * Keep focus on debugger input box whenever possible. * Echo stdout/stderr in the Observatory debugger. Standalone-only so far. * Minor fixes to service protocol documentation. * Pub * **Breaking:** various commands that previously ran `pub get` implicitly no longer do so. Instead, they merely check to make sure the ".packages" file is newer than the pubspec and the lock file, and fail if it's not. * Added support for `--verbosity=error` and `--verbosity=warning`. * `pub serve` now collapses multiple GET requests into a single line of output. For full output, use `--verbose`. * `pub deps` has improved formatting for circular dependencies on the entrypoint package. * `pub run` and `pub global run` * **Breaking:** to match the behavior of the Dart VM, executables no longer run in checked mode by default. A `--checked` flag has been added to run them in checked mode manually. * Faster start time for executables that don't import transformed code. * Binstubs for globally-activated executables are now written in the system encoding, rather than always in `UTF-8`. To update existing executables, run `pub cache repair`. * `pub get` and `pub upgrade` * Pub will now generate a ".packages" file in addition to the "packages" directory when running `pub get` or similar operations, per the [package spec proposal][]. Pub now has a `--no-package-symlinks` flag that will stop "packages" directories from being generated at all. * An issue where HTTP requests were sometimes made even though `--offline` was passed has been fixed. * A bug with `--offline` that caused an unhelpful error message has been fixed. * Pub will no longer time out when a package takes a long time to download. * `pub publish` * Pub will emit a non-zero exit code when it finds a violation while publishing. * `.gitignore` files will be respected even if the package isn't at the top level of the Git repository. * Barback integration * A crashing bug involving transformers that only apply to non-public code has been fixed. * A deadlock caused by declaring transformer followed by a lazy transformer (such as the built-in `$dart2js` transformer) has been fixed. * A stack overflow caused by a transformer being run multiple times on the package that defines it has been fixed. * A transformer that tries to read a non-existent asset in another package will now be re-run if that asset is later created. [package spec proposal]: https://github.com/lrhn/dep-pkgspec ### VM Service Protocol Changes * **BREAKING** The service protocol now sends JSON-RPC 2.0-compatible server-to-client events. To reflect this, the service protocol version is now 2.0. * The service protocol now includes a `"jsonrpc"` property in its responses, as opposed to `"json-rpc"`. * The service protocol now properly handles requests with non-string ids. Numeric ids are no longer converted to strings, and null ids now don't produce a response. * Some RPCs that didn't include a `"jsonrpc"` property in their responses now include one. ## 1.11.2 - 2015-08-03 ### Core library changes * Fix a bug where `WebSocket.close()` would crash if called after `WebSocket.cancel()`. ## 1.11.1 - 2015-07-02 ### Tool changes * Pub will always load Dart SDK assets from the SDK whose `pub` executable was run, even if a `DART_SDK` environment variable is set. ## 1.11.0 - 2015-06-25 ### Core library changes * `dart:core` * `Iterable` added an `empty` constructor. [dcf0286](https://github.com/dart-lang/sdk/commit/dcf0286f5385187a68ce9e66318d3bf19abf454b) * `Iterable` can now be extended directly. An alternative to extending `IterableBase` from `dart:collection`. * `List` added an `unmodifiable` constructor. [r45334](https://code.google.com/p/dart/source/detail?r=45334) * `Map` added an `unmodifiable` constructor. [r45733](https://code.google.com/p/dart/source/detail?r=45733) * `int` added a `gcd` method. [a192ef4](https://github.com/dart-lang/sdk/commit/a192ef4acb95fad1aad1887f59eed071eb5e8201) * `int` added a `modInverse` method. [f6f338c](https://github.com/dart-lang/sdk/commit/f6f338ce67eb8801b350417baacf6d3681b26002) * `StackTrace` added a `fromString` constructor. [68dd6f6](https://github.com/dart-lang/sdk/commit/68dd6f6338e63d0465041d662e778369c02c2ce6) * `Uri` added a `directory` constructor. [d8dbb4a](https://github.com/dart-lang/sdk/commit/d8dbb4a60f5e8a7f874c2a4fbf59eaf1a39f4776) * List iterators may not throw `ConcurrentModificationError` as eagerly in release mode. In checked mode, the modification check is still as eager as possible. [r45198](https://github.com/dart-lang/sdk/commit/5a79c03) * `dart:developer` - **NEW** * Replaces the deprecated `dart:profiler` library. * Adds new functions `debugger` and `inspect`. [6e42aec](https://github.com/dart-lang/sdk/blob/6e42aec4f64cf356dde7bad9426e07e0ea5b58d5/sdk/lib/developer/developer.dart) * `dart:io` * `FileSystemEntity` added a `uri` property. [8cf32dc](https://github.com/dart-lang/sdk/commit/8cf32dc1a1664b516e57f804524e46e55fae88b2) * `Platform` added a `static resolvedExecutable` property. [c05c8c6](https://github.com/dart-lang/sdk/commit/c05c8c66069db91cc2fd48691dfc406c818d411d) * `dart:html` * `Element` methods, `appendHtml` and `insertAdjacentHtml` now take `nodeValidator` and `treeSanitizer` parameters, and the inputs are consistently sanitized. [r45818 announcement](https://groups.google.com/a/dartlang.org/forum/#!topic/announce/GVO7EAcPi6A) * `dart:isolate` * **BREAKING** The positional `priority` parameter of `Isolate.ping` and `Isolate.kill` is now a named parameter named `priority`. * **BREAKING** Removed the `Isolate.AS_EVENT` priority. * `Isolate` methods `ping` and `addOnExitListener` now have a named parameter `response`. [r45092](https://github.com/dart-lang/sdk/commit/1b208bd) * `Isolate.spawnUri` added a named argument `checked`. * Remove the experimental state of the API. * `dart:profiler` - **DEPRECATED** * This library will be removed in 1.12. Use `dart:developer` instead. ### Tool changes * This is the first release that does not include the Eclipse-based **Dart Editor**. See [dartlang.org/tools](https://www.dartlang.org/tools/) for alternatives. * This is the last release that ships the (unsupported) dart2dart (aka `dart2js --output-type=dart`) utility as part of dart2js ## 1.10.0 – 2015-04-29 ### Core library changes * `dart:convert` * **POTENTIALLY BREAKING** Fix behavior of `HtmlEscape`. It no longer escapes no-break space (U+00A0) anywhere or forward slash (`/`, `U+002F`) in element context. Slash is still escaped using `HtmlEscapeMode.UNKNOWN`. [r45003](https://github.com/dart-lang/sdk/commit/8b8223d), [r45153](https://github.com/dart-lang/sdk/commit/8a5d049), [r45189](https://github.com/dart-lang/sdk/commit/3c39ad2) * `dart:core` * `Uri.parse` added `start` and `end` positional arguments. * `dart:html` * **POTENTIALLY BREAKING** `CssClassSet` method arguments must now be 'tokens', i.e. non-empty strings with no white-space characters. The implementation was incorrect for class names containing spaces. The fix is to forbid spaces and provide a faster implementation. [Announcement](https://groups.google.com/a/dartlang.org/d/msg/announce/jmUI2XJHfC8/UZUCvJH3p2oJ) * `dart:io` * `ProcessResult` now exposes a constructor. * `import` and `Isolate.spawnUri` now supports the [Data URI scheme](http://en.wikipedia.org/wiki/Data_URI_scheme) on the VM. ## Tool Changes ### pub * Running `pub run foo` within a package now runs the `foo` executable defined by the `foo` package. The previous behavior ran `bin/foo`. This makes it easy to run binaries in dependencies, for instance `pub run test`. * On Mac and Linux, signals sent to `pub run` and forwarded to the child command. ## 1.9.3 – 2015-04-14 This is a bug fix release which merges a number of commits from `bleeding_edge`. * dart2js: Addresses as issue with minified Javascript output with CSP enabled - [r44453](https://code.google.com/p/dart/source/detail?r=44453) * Editor: Fixes accidental updating of files in the pub cache during rename refactoring - [r44677](https://code.google.com/p/dart/source/detail?r=44677) * Editor: Fix for [issue 23032](https://code.google.com/p/dart/issues/detail?id=23032) regarding skipped breakpoints on Windows - [r44824](https://code.google.com/p/dart/source/detail?r=44824) * dart:mirrors: Fix `MethodMirror.source` when the method is on the first line in a script - [r44957](https://code.google.com/p/dart/source/detail?r=44957), [r44976](https://code.google.com/p/dart/source/detail?r=44976) * pub: Fix for [issue 23084](https://code.google.com/p/dart/issues/detail?id=23084): Pub can fail to load transformers necessary for local development - [r44876](https://code.google.com/p/dart/source/detail?r=44876) ## 1.9.1 – 2015-03-25 ### Language changes * Support for `async`, `await`, `sync*`, `async*`, `yield`, `yield*`, and `await for`. See the [the language tour][async] for more details. * Enum support is fully enabled. See [the language tour][enum] for more details. [async]: https://www.dartlang.org/docs/dart-up-and-running/ch02.html#asynchrony [enum]: https://www.dartlang.org/docs/dart-up-and-running/ch02.html#enums ### Tool changes * The formatter is much more comprehensive and generates much more readable code. See [its tool page][dartfmt] for more details. * The analysis server is integrated into the IntelliJ plugin and the Dart editor. This allows analysis to run out-of-process, so that interaction remains smooth even for large projects. * Analysis supports more and better hints, including unused variables and unused private members. [dartfmt]: https://www.dartlang.org/tools/dartfmt/ ### Core library changes #### Highlights * There's a new model for shared server sockets with no need for a `Socket` reference. * A new, much faster [regular expression engine][regexp]. * The Isolate API now works across the VM and `dart2js`. [regexp]: http://news.dartlang.org/2015/02/irregexp-dart-vms-new-regexp.html #### Details For more information on any of these changes, see the corresponding documentation on the [Dart API site](http://api.dartlang.org). * `dart:async`: * `Future.wait` added a new named argument, `cleanUp`, which is a callback that releases resources allocated by a successful `Future`. * The `SynchronousStreamController` class was added as an explicit name for the type returned when the `sync` argument is passed to `new StreamController`. * `dart:collection`: The `new SplayTreeSet.from(Iterable)` constructor was added. * `dart:convert`: `Utf8Encoder.convert` and `Utf8Decoder.convert` added optional `start` and `end` arguments. * `dart:core`: * `RangeError` added new static helper functions: `checkNotNegative`, `checkValidIndex`, `checkValidRange`, and `checkValueInInterval`. * `int` added the `modPow` function. * `String` added the `replaceFirstMapped` and `replaceRange` functions. * `dart:io`: * Support for locking files to prevent concurrent modification was added. This includes the `File.lock`, `File.lockSync`, `File.unlock`, and `File.unlockSync` functions as well as the `FileLock` class. * Support for starting detached processes by passing the named `mode` argument (a `ProcessStartMode`) to `Process.start`. A process can be fully attached, fully detached, or detached except for its standard IO streams. * `HttpServer.bind` and `HttpServer.bindSecure` added the `v6Only` named argument. If this is true, only IPv6 connections will be accepted. * `HttpServer.bind`, `HttpServer.bindSecure`, `ServerSocket.bind`, `RawServerSocket.bind`, `SecureServerSocket.bind` and `RawSecureServerSocket.bind` added the `shared` named argument. If this is true, multiple servers or sockets in the same Dart process may bind to the same address, and incoming requests will automatically be distributed between them. * **Deprecation:** the experimental `ServerSocketReference` and `RawServerSocketReference` classes, as well as getters that returned them, are marked as deprecated. The `shared` named argument should be used instead. These will be removed in Dart 1.10. * `Socket.connect` and `RawSocket.connect` added the `sourceAddress` named argument, which specifies the local address to bind when making a connection. * The static `Process.killPid` method was added to kill a process with a given PID. * `Stdout` added the `nonBlocking` instance property, which returns a non-blocking `IOSink` that writes to standard output. * `dart:isolate`: * The static getter `Isolate.current` was added. * The `Isolate` methods `addOnExitListener`, `removeOnExitListener`, `setErrorsFatal`, `addOnErrorListener`, and `removeOnErrorListener` now work on the VM. * Isolates spawned via `Isolate.spawn` now allow most objects, including top-level and static functions, to be sent between them. ## 1.8.5 – 2015-01-21 * Code generation for SIMD on ARM and ARM64 is fixed. * A possible crash on MIPS with newer GCC toolchains has been prevented. * A segfault when using `rethrow` was fixed ([issue 21795][]). [issue 21795]: https://code.google.com/p/dart/issues/detail?id=21795 ## 1.8.3 – 2014-12-10 * Breakpoints can be set in the Editor using file suffixes ([issue 21280][]). * IPv6 addresses are properly handled by `HttpClient` in `dart:io`, fixing a crash in pub ([issue 21698][]). * Issues with the experimental `async`/`await` syntax have been fixed. * Issues with a set of number operations in the VM have been fixed. * `ListBase` in `dart:collection` always returns an `Iterable` with the correct type argument. [issue 21280]: https://code.google.com/p/dart/issues/detail?id=21280 [issue 21698]: https://code.google.com/p/dart/issues/detail?id=21698 ## 1.8.0 – 2014-11-28 * `dart:collection`: `SplayTree` added the `toSet` function. * `dart:convert`: The `JsonUtf8Encoder` class was added. * `dart:core`: * The `IndexError` class was added for errors caused by an index being outside its expected range. * The `new RangeError.index` constructor was added. It forwards to `new IndexError`. * `RangeError` added three new properties. `invalidProperty` is the value that caused the error, and `start` and `end` are the minimum and maximum values that the value is allowed to assume. * `new RangeError.value` and `new RangeError.range` added an optional `message` argument. * The `new String.fromCharCodes` constructor added optional `start` and `end` arguments. * `dart:io`: * Support was added for the [Application-Layer Protocol Negotiation][alpn] extension to the TLS protocol for both the client and server. * `SecureSocket.connect`, `SecureServerSocket.bind`, `RawSecureSocket.connect`, `RawSecureSocket.secure`, `RawSecureSocket.secureServer`, and `RawSecureServerSocket.bind` added a `supportedProtocols` named argument for protocol negotiation. * `RawSecureServerSocket` added a `supportedProtocols` field. * `RawSecureSocket` and `SecureSocket` added a `selectedProtocol` field which contains the protocol selected during protocol negotiation. [alpn]: https://tools.ietf.org/html/rfc7301 ## 1.7.0 – 2014-10-15 ### Tool changes * `pub` now generates binstubs for packages that are globally activated so that they can be put on the user's `PATH` and used as normal executables. See the [`pub global activate` documentation][pub global activate]. * When using `dart2js`, deferred loading now works with multiple Dart apps on the same page. [pub global activate]: https://www.dartlang.org/tools/pub/cmd/pub-global.html#running-a-script-from-your-path ### Core library changes * `dart:async`: `Zone`, `ZoneDelegate`, and `ZoneSpecification` added the `errorCallback` function, which allows errors that have been programmatically added to a `Future` or `Stream` to be intercepted. * `dart:io`: * **Breaking change:** `HttpClient.close` must be called for all clients or they will keep the Dart process alive until they time out. This fixes the handling of persistent connections. Previously, the client would shut down immediately after a request. * **Breaking change:** `HttpServer` no longer compresses all traffic by default. The new `autoCompress` property can be set to `true` to re-enable compression. * `dart:isolate`: `Isolate.spawnUri` added the optional `packageRoot` argument, which controls how it resolves `package:` URIs.