flutter/packages/flutter_tools
Jackson Gardner 3c30e3cb20
Flutter Web Bootstrapping Improvements (#144434)
This makes several changes to flutter web app bootstrapping.
* The build now produces a `flutter_bootstrap.js` file.
  * By default, this file does the basic streamlined startup of a flutter app with the service worker settings and no user configuration.
  * The user can also put a `flutter_bootstrap.js` file in the `web` subdirectory in the project directory which can have whatever custom bootstrapping logic they'd like to write instead. This file is also templated, and can use any of the tokens  that can be used with the `index.html` (with the exception of `{{flutter_bootstrap_js}}`, see below).
* Introduced a few new templating tokens for `index.html`:
  * `{{flutter_js}}` => inlines the entirety of `flutter.js`
  * `{{flutter_service_worker_version}}` => replaced directly by the service worker version. This can be used instead of the script that sets the `serviceWorkerVersion` local variable that we used to have by default.
  * `{{flutter_bootstrap_js}}` => inlines the entirety of `flutter_bootstrap.js` (this token obviously doesn't apply to `flutter_bootstrap.js` itself).
* Changed `IndexHtml` to be called `WebTemplate` instead, since it is used for more than just the index.html now.
* We now emit warnings at build time for certain deprecated flows:
  * Warn on the old service worker version pattern (i.e.`(const|var) serviceWorkerVersion = null`) and recommends using `{{flutter_service_worker_version}}` token instead
  * Warn on use of `FlutterLoader.loadEntrypoint` and recommend using `FlutterLoader.load` instead
  * Warn on manual loading of `flutter_service_worker.js`.
* The default `index.html` on `flutter create` now uses an async script tag with `flutter_bootstrap.js`.
2024-03-12 22:41:26 +00:00
..
bin Reland "Add FlutterMacOS.xcframework artifact (#143244)" (#144275) 2024-02-28 20:09:54 +00:00
doc [flutter_tools] Ensure flutter daemon clients can detect preview device (#140112) 2023-12-21 19:01:16 +00:00
gradle Update android templates to use target sdk 34 (#144641) 2024-03-06 19:15:07 +00:00
ide_templates/intellij Remove .pub directories from iml templates (#109622) 2022-09-09 22:20:12 +00:00
lib Flutter Web Bootstrapping Improvements (#144434) 2024-03-12 22:41:26 +00:00
static Reland "Remove references to Observatory (#118577)" (#121606) 2023-02-28 11:57:04 -05:00
templates Flutter Web Bootstrapping Improvements (#144434) 2024-03-12 22:41:26 +00:00
test Flutter Web Bootstrapping Improvements (#144434) 2024-03-12 22:41:26 +00:00
tool Remove custom unawaited, prefer dart:async version (#103212) 2022-05-07 08:49:04 -07:00
analysis_options.yaml Unify analysis options (#108462) 2022-07-28 09:07:49 -07:00
dart_test.yaml Some test cleanup for flutter_tools. (#90227) 2021-10-01 10:38:02 -07:00
pubspec.yaml Manually roll pub packages (#145005) 2024-03-12 19:53:57 +00:00
README.md Update dev/bots/test.dart (and friends) to provide --local-engine-host. (#132354) 2023-08-14 13:21:14 -07:00

Flutter Tools

This section of the Flutter repository contains the command line developer tools for building Flutter applications.

Working on Flutter Tools

Be sure to follow the instructions on CONTRIBUTING.md to set up your development environment. Further, familiarize yourself with the style guide, which we follow.

Setting up

First, ensure that the Dart SDK and other necessary artifacts are available by invoking the Flutter Tools wrapper script. In this directory run:

$ flutter --version

Running the Tool

To run Flutter Tools from source, in this directory run:

$ dart bin/flutter_tools.dart

followed by command-line arguments, as usual.

Running the analyzer

To run the analyzer on Flutter Tools, in this directory run:

$ flutter analyze

Writing tests

As with other parts of the Flutter repository, all changes in behavior must be tested. Tests live under the test/ subdirectory.

  • Hermetic unit tests of tool internals go under test/general.shard and must run in significantly less than two seconds.

  • Tests of tool commands go under test/commands.shard. Hermetic tests go under its hermetic/ subdirectory. Non-hermetic tests go under its permeable sub-directory. Avoid adding tests here and prefer writing either a unit test or a full integration test.

  • Integration tests (e.g. tests that run the tool in a subprocess) go under test/integration.shard.

  • Slow web-related tests go in the test/web.shard directory.

In general, the tests for the code in a file called file.dart should go in a file called file_test.dart in the subdirectory that matches the behavior of the test.

The dart_test.yaml file configures the timeout for these tests to be 15 minutes. The test.dart script that is used in CI overrides this to two seconds for the test/general.shard directory, to catch behaviour that is unexpectedly slow.

Please avoid setting any other timeouts.

Using local engine builds in integration tests

The integration tests can be configured to use a specific local engine variant by setting the FLUTTER_LOCAL_ENGINE and FLUTTER_LOCAL_ENGINE_HOST environment svariable to the name of the local engines (e.g. android_debug_unopt and host_debug_unopt). If the local engine build requires a source path, this can be provided by setting the FLUTTER_LOCAL_ENGINE_SRC_PATH environment variable. This second variable is not necessary if the flutter and engine checkouts are in adjacent directories.

export FLUTTER_LOCAL_ENGINE=android_debug_unopt
export FLUTTER_LOCAL_ENGINE_HOST=host_debug_unopt
flutter test test/integration.shard/some_test_case

Running the tests

To run all of the unit tests:

$ flutter test test/general.shard

The tests in test/integration.shard are slower to run than the tests in test/general.shard. Depending on your development computer, you might want to limit concurrency. Generally it is easier to run these on CI, or to manually verify the behavior you are changing instead of running the test.

The integration tests also require the FLUTTER_ROOT environment variable to be set. The full invocation to run everything might therefore look something like:

$ export FLUTTER_ROOT=~/path/to/flutter-sdk
$ flutter test --concurrency 1

This may take some time (on the order of an hour). The unit tests alone take much less time (on the order of a minute).

You can run the tests in a specific file, e.g.:

$ flutter test test/general.shard/utils_test.dart

Forcing snapshot regeneration

To force the Flutter Tools snapshot to be regenerated, delete the following files:

$ rm ../../bin/cache/flutter_tools.stamp ../../bin/cache/flutter_tools.snapshot