[js_interop_checks] Update SDK constraint to support Dart 3

The package already uses 3.0 features after 3b294fdab2, but the usage wasn't caught due to https://github.com/dart-lang/sdk/issues/54764.

Since all packages that depend on this all require Dart 3 or greater now, we can increase the constraint and start to take advantage of its features. Also avoids a few checks and lookups :)

Change-Id: Iba539b86dc2f0117406b96e60ed8e92ea9ecf220
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/349161
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Srujan Gaddam <srujzs@google.com>

pkg/_js_interop_checks/lib/js_interop_checks.dart

@@ -379,7 +379,7 @@ class JsInteropChecks extends RecursiveVisitor {
               (hasDartJSInteropAnnotation(node) ||
                   _libraryHasDartJSInteropAnnotation)) {
         _checkNoParamInitializersForStaticInterop(node.function);
-        late Annotatable? annotatable;
+        final Annotatable? annotatable;
         if (node.isExtensionTypeMember) {
           annotatable = extensionIndex.getExtensionType(node);
         } else if (node.isExtensionMember) {
@@ -683,7 +683,7 @@ class JsInteropChecks extends RecursiveVisitor {
     // TODO(srujzs): Delete the check for patched member once
     // https://github.com/dart-lang/sdk/issues/53367 is resolved.
     if (member.isExternal && !JsInteropChecks.isPatchedMember(member)) {
-      var memberKind = '';
+      final String memberKind;
       var memberName = '';
       if (member.isExtensionTypeMember) {
         // Extension type interop members can not be torn off.
@@ -946,7 +946,7 @@ class JsInteropChecks extends RecursiveVisitor {
     } else if (type is ExtensionType) {
       // Extension types that wrap other allowed types are also okay. Interop
       // extension types are handled above, so this is essentially for extension
-      // types on primtives.
+      // types on primitives.
       return _isAllowedExternalType(type.extensionTypeErasure);
     }
     return false;

pkg/_js_interop_checks/lib/src/transformations/export_checker.dart

@@ -21,13 +21,6 @@ enum ExportStatus {
   nonExportable,
 }
 
-class GetSet {
-  Member? getter;
-  Member? setter;
-
-  GetSet(this.getter, this.setter);
-}
-
 class ExportChecker {
   final JsInteropDiagnosticReporter _diagnosticReporter;
   final Map<Reference, Map<String, Set<Member>>> exportClassToMemberMap = {};
@@ -45,7 +38,7 @@ class ExportChecker {
   ///
   /// [exports] should be a set of members from the [exportClassToMemberMap]. If
   /// missing a getter and/or setter, the corresponding field will be `null`.
-  GetSet getGetterSetter(Set<Member> exports) {
+  ({Member? getter, Member? setter}) getGetterSetter(Set<Member> exports) {
     assert(exports.isNotEmpty && exports.length <= 2);
     Member? getter;
     Member? setter;
@@ -71,7 +64,7 @@ class ExportChecker {
       }
     }
 
-    return GetSet(getter, setter);
+    return (getter: getter, setter: setter);
   }
 
   /// Calculates the overrides, including inheritance, for [cls].
@@ -84,7 +77,7 @@ class ExportChecker {
     var superclass = cls.superclass;
     if (superclass != null && superclass != _objectClass) {
       _collectOverrides(superclass);
-      memberMap = Map.from(_overrideMap[superclass.reference]!);
+      memberMap = Map.of(_overrideMap[superclass.reference]!);
     } else {
       memberMap = {};
     }
@@ -156,8 +149,8 @@ class ExportChecker {
 
     // Walk through the export map and determine if there are any unresolvable
     // conflicts.
-    for (var exportName in exports.keys) {
-      var existingMembers = exports[exportName]!;
+    for (var MapEntry(key: exportName, value: existingMembers)
+        in exports.entries) {
       if (existingMembers.length == 1) continue;
       if (existingMembers.length == 2) {
         // There are two instances where you can resolve collisions:

pkg/_js_interop_checks/lib/src/transformations/js_util_optimizer.dart

@@ -66,7 +66,7 @@ class JsUtilOptimizer extends Transformer {
   final CoreTypes _coreTypes;
   final StatefulStaticTypeContext _staticTypeContext;
 
-  late final ExtensionIndex _extensionIndex;
+  final ExtensionIndex _extensionIndex;
 
   JsUtilOptimizer(
       this._coreTypes, ClassHierarchy hierarchy, this._extensionIndex)
@@ -112,7 +112,7 @@ class JsUtilOptimizer extends Transformer {
             TypeEnvironment(_coreTypes, hierarchy));
 
   @override
-  visitLibrary(Library node) {
+  TreeNode visitLibrary(Library node) {
     _staticTypeContext.enterLibrary(node);
     node.transformChildren(this);
     _staticTypeContext.leaveLibrary(node);
@@ -120,7 +120,7 @@ class JsUtilOptimizer extends Transformer {
   }
 
   @override
-  defaultMember(Member node) {
+  TreeNode defaultMember(Member node) {
     _staticTypeContext.enterMember(node);
     node.transformChildren(this);
     _staticTypeContext.leaveMember(node);
@@ -382,19 +382,13 @@ class JsUtilOptimizer extends Transformer {
     // TODO(srujzs): Support more operators for overloading using some
     // combination of Dart-defineable operators and @JS renaming for the ones
     // that are not renameable.
-    late Procedure target;
-    switch (operator) {
-      case '[]':
-        target =
-            shouldTrustType ? _getPropertyTrustTypeTarget : _getPropertyTarget;
-        break;
-      case '[]=':
-        target = _setPropertyTarget;
-        break;
-      default:
-        throw UnimplementedError(
-            'External operator $operator is unsupported for static interop. ');
-    }
+    final target = switch (operator) {
+      '[]' =>
+        shouldTrustType ? _getPropertyTrustTypeTarget : _getPropertyTarget,
+      '[]=' => _setPropertyTarget,
+      _ => throw UnimplementedError(
+          'External operator $operator is unsupported for static interop. ')
+    };
 
     return (Arguments arguments, Expression invocation) {
       return StaticInvocation(

pkg/_js_interop_checks/lib/src/transformations/shared_interop_transformer.dart

@@ -276,8 +276,7 @@ class SharedInteropTransformer extends Transformer {
       ..fileOffset = invocation.fileOffset;
     block.add(jsExporter);
 
-    for (var exportName in exportMap.keys) {
-      var exports = exportMap[exportName]!;
+    for (var MapEntry(key: exportName, value: exports) in exportMap.entries) {
       ExpressionStatement setProperty(
           VariableGet jsObject, String propertyName, StaticInvocation jsValue) {
         // `jsObject[propertyName] = jsValue`
@@ -338,9 +337,7 @@ class SharedInteropTransformer extends Transformer {
             isSynthesized: true)
           ..fileOffset = invocation.fileOffset;
         block.add(getSetMap);
-        var getSet = _exportChecker.getGetterSetter(exports);
-        var getter = getSet.getter;
-        var setter = getSet.setter;
+        var (:getter, :setter) = _exportChecker.getGetterSetter(exports);
         if (getter != null) {
           final resultType = _staticInteropMockValidator.typeParameterResolver
               .resolve(getter.getterType);

pkg/_js_interop_checks/lib/src/transformations/static_interop_class_eraser.dart

@@ -47,7 +47,7 @@ class StaticInteropClassEraser extends Transformer {
   // Visiting core libraries that don't contain `@staticInterop` adds overhead.
   // To avoid this, we use an allowlist that contains libraries that we know use
   // `@staticInterop`.
-  late final Set<String> _erasableCoreLibraries = {
+  final Set<String> _erasableCoreLibraries = {
     'js_interop_unsafe',
     'ui',
     'ui_web',

pkg/_js_interop_checks/lib/src/transformations/static_interop_mock_validator.dart

@@ -104,9 +104,8 @@ class StaticInteropMockValidator {
         _computeImplementableExtensionMembers(staticInteropClass);
     var exportMap = _exportChecker.exportClassToMemberMap[dartClass.reference]!;
 
-    for (var exportName in exportNameToDescriptors.keys) {
-      var descriptors = exportNameToDescriptors[exportName]!;
-
+    for (var MapEntry(key: exportName, value: descriptors)
+        in exportNameToDescriptors.entries) {
       String getAsErrorString(Iterable<ExtensionMemberDescriptor> descriptors) {
         var withExtensionNameAndType = descriptors.map((descriptor) {
           var extension = _descriptorToExtensionName[descriptor]!;
@@ -139,7 +138,7 @@ class StaticInteropMockValidator {
           hasImplementation = descriptors
               .any((descriptor) => _implements(firstMember, descriptor));
         } else {
-          var getSet = _exportChecker.getGetterSetter(dartMembers);
+          var (:getter, :setter) = _exportChecker.getGetterSetter(dartMembers);
 
           var getters = <ExtensionMemberDescriptor>{};
           var setters = <ExtensionMemberDescriptor>{};
@@ -148,10 +147,10 @@ class StaticInteropMockValidator {
           var implementsSetter = false;
           for (var descriptor in descriptors) {
             if (descriptor.isGetter) {
-              implementsGetter |= _implements(getSet.getter, descriptor);
+              implementsGetter |= _implements(getter, descriptor);
               getters.add(descriptor);
             } else if (descriptor.isSetter) {
-              implementsSetter |= _implements(getSet.setter, descriptor);
+              implementsSetter |= _implements(setter, descriptor);
               setters.add(descriptor);
             }
           }
@@ -288,8 +287,8 @@ class StaticInteropMockValidator {
     // Process the stored libraries, and create a mapping between @staticInterop
     // classes and their extensions.
     var staticInteropClassesWithExtensions = <Reference, Set<Extension>>{};
-    for (var library in ExportChecker.libraryExtensionMap.keys) {
-      for (var extension in ExportChecker.libraryExtensionMap[library]!) {
+    for (var extensions in ExportChecker.libraryExtensionMap.values) {
+      for (var extension in extensions) {
         var onType = extension.onType as InterfaceType;
         staticInteropClassesWithExtensions
             .putIfAbsent(onType.classReference, () => {})

pkg/_js_interop_checks/pubspec.yaml

@@ -3,7 +3,7 @@ name: _js_interop_checks
 publish_to: none
 
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: ^3.0.0
 
 # Use 'any' constraints here; we get our versions from the DEPS file.
 dependencies: