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`.
Partial implementation of https://github.com/flutter/flutter/issues/143348
This enables asset transformation during hot reload (except for web, because that has its own implementation of `DevFS` ð). Asset transformers will be reapplied after changing any asset and performing a hot reload during `flutter run`.
### Context:
DDC modules are abstractions over how libraries are loaded/updated. The entirety of google3 uses the DDC/legacy module system due to its flexibility extensibility over the other two (ES6 and AMD/RequireJS). Unifying DDC's module system saves us from duplicating work and will allow us to have finer grained control over how JS modules are loaded. This is a a prerequisite to features such as hot reload.
### Overview:
This change plumbs a boolean flag through flutter_tools that switches between DDC (new) and AMD (current) modules. This mode is automatically applied when `--extra-front-end-options=--dartdevc-module-format=ddc` is specified alongside `flutter run`. Other important additions include:
* Splitting Flutter artifacts between DDC and AMD modules
* Adding unit tests for the DDC module system
* Additional bootstrapper logic for the DDC module system
We don't expect to see any user-visible behavior or performance differences.
This is dependent on [incoming module system support in DWDS](https://github.com/dart-lang/webdev/pull/2295) and [additional artifacts in the engine](https://github.com/flutter/engine/pull/47783).
This is part of a greater effort to deprecate the AMD module system: https://github.com/dart-lang/sdk/issues/52361
This is an attempt at a reland of https://github.com/flutter/flutter/pull/141396
The main changes here that are different than the original PR is fixes to wire up the `flutter test` command properly with the web renderer.
Dual Web Compile has had some issues where `flutter test` is not respecting the `--web-renderer` flag for some reason. I haven't gotten entirely to the bottom of the issue, but for now we need to rever these changes while I investigate. This reverts the following PRs:
https://github.com/flutter/flutter/pull/143128https://github.com/flutter/flutter/pull/141396
While doing this revert, I had a few merge conflicts with https://github.com/flutter/flutter/pull/142760, and I tried to resolve the merge conflicts within the spirit of that PR's change, but @chingjun I might need your input on whether the imports I have modified are okay with regards to the change you were making.
Add a new `BuildTargets` class that provides commonly used build targets. And avoid importing files from `build_system/targets` except from the top level entrypoints or from top level commands.
Also move `scene_importer.dart` and `shader_compiler.dart` into `build_system/tools` because they are not `Target` classes, but wrapper for certain tools.
With this change, we can ignore all files in `build_system/targets` internally and make PR #142709 easier to land internally. See cl/603434066 for the corresponding internal change.
Related to:
https://github.com/flutter/flutter/pull/142709https://github.com/flutter/flutter/issues/142041
Also note that I have opted to add a new variable in `globals.dart` for `BuildTargets` in this PR, but I know that we are trying to get rid of globals. Several alternatives that I was considering:
1. Add a new field in `BuildSystem` that returns a `BuildTargets` instance. Since `BuildSystem` is already in `globals`, we can access build targets using `globals.buildSystem.buildTargets` without adding a new global variable.
2. Properly inject the `BuildTargetsImpl` instance from the top level `executable.dart` and top level commands.
Let me know if you want me to do one of the above instead. Thanks!
This implements dual compile via the newly available flutter.js bootstrapping APIs for intelligent build fallback.
* Users can now use the `FlutterLoader.load` API from flutter.js
* Flutter tool injects build info into the `index.html` of the user so that the bootstrapper knows which build variants are available to bootstrap
* The semantics of the `--wasm` flag for `flutter build web` have changed:
- Instead of producing a separate `build/web_wasm` directory, the output goes to the `build/web` directory like a normal web build
- Produces a dual build that contains two build variants: dart2wasm+skwasm and dart2js+CanvasKit. The dart2wasm+skwasm will only work on Chrome in a cross-origin isolated context, all other environments will fall back to dart2js+CanvasKit.
- `--wasm` and `--web-renderer` are now mutually exclusive. Since there are multiple build variants with `--wasm`, the web renderer cannot be expressed via a single command-line flag. For now, we are hard coding what build variants are produced with the `--wasm` flag, but I plan on making this more customizable in the future.
* Build targets now can optionally provide a "build key" which can uniquely identify any specific parameterization of that build target. This way, the build target can invalidate itself by changing its build key. This works a bit better than just stuffing everything into the environment defines because (a) it doesn't invalidate the entire build, just the targets which are affected and (b) settings for multiple build variants don't translate well to the flat map of environment defines.
Refactors `ShaderTarget` to make it opaque as to whether it's using Impeller or SkSL and instead has it focus on the target platform it's generating for.
ImpellerC includes SkSL right now whether you ask for it or not.
The tester target also might need SkSL or Vulkan depending on whether `--enable-impeller` is passed.
Adds support for a new --web-header option to flutter run.
Creates a workaround for https://github.com/flutter/flutter/issues/127902
This PR allows adding additional headers for the flutter run web server. This is useful to add headers like Cross-Origin-Embedder-Policy and Cross-Origin-Opener-Policy without the use of a proxy server. These headers are required enable advanced web features. This approach provides flexibility to the developer to make use of the feature as they see fit and is backward-compatible. One tradeoff is that it increases the surface area to support for future changes to the flutter web server.
https://github.com/flutter/flutter/issues/127902 is not fully addressed by this change. The solution for that task will be more opinionated. This PR creates a general-purpose workaround for anyone who needs a solution sooner while the bigger solution is developed.
Support for FFI calls with `@Native external` functions through Native assets on MacOS and iOS. This enables bundling native code without any build-system boilerplate code.
For more info see:
* https://github.com/flutter/flutter/issues/129757
### Implementation details for MacOS and iOS.
Dylibs are bundled by (1) making them fat binaries if multiple architectures are targeted, (2) code signing these, and (3) copying them to the frameworks folder. These steps are done manual rather than via CocoaPods. CocoaPods would have done the same steps, but (a) needs the dylibs to be there before the `xcodebuild` invocation (we could trick it, by having a minimal dylib in the place and replace it during the build process, that works), and (b) can't deal with having no dylibs to be bundled (we'd have to bundle a dummy dylib or include some dummy C code in the build file).
The dylibs are build as a new target inside flutter assemble, as that is the moment we know what build-mode and architecture to target.
The mapping from asset id to dylib-path is passed in to every kernel compilation path. The interesting case is hot-restart where the initial kernel file is compiled by the "inner" flutter assemble, while after hot restart the "outer" flutter run compiled kernel file is pushed to the device. Both kernel files need to contain the mapping. The "inner" flutter assemble gets its mapping from the NativeAssets target which builds the native assets. The "outer" flutter run get its mapping from a dry-run invocation. Since this hot restart can be used for multiple target devices (`flutter run -d all`) it contains the mapping for all known targets.
### Example vs template
The PR includes a new template that uses the new native assets in a package and has an app importing that. Separate discussion in: https://github.com/flutter/flutter/issues/131209.
### Tests
This PR adds new tests to cover the various use cases.
* dev/devicelab/bin/tasks/native_assets_ios.dart
* Runs an example app with native assets in all build modes, doing hot reload and hot restart in debug mode.
* dev/devicelab/bin/tasks/native_assets_ios_simulator.dart
* Runs an example app with native assets, doing hot reload and hot restart.
* packages/flutter_tools/test/integration.shard/native_assets_test.dart
* Runs (incl hot reload/hot restart), builds, builds frameworks for iOS, MacOS and flutter-tester.
* packages/flutter_tools/test/general.shard/build_system/targets/native_assets_test.dart
* Unit tests the new Target in the backend.
* packages/flutter_tools/test/general.shard/ios/native_assets_test.dart
* packages/flutter_tools/test/general.shard/macos/native_assets_test.dart
* Unit tests the native assets being packaged on a iOS/MacOS build.
It also extends various existing tests:
* dev/devicelab/bin/tasks/module_test_ios.dart
* Exercises the add2app scenario.
* packages/flutter_tools/test/general.shard/features_test.dart
* Unit test the new feature flag.
Update test expectations from application/javascript -> text/javascript
`package:mime` now uses `text/javascript` and not `application/javascript`.
See https://github.com/dart-lang/mime/pull/76.
See https://datatracker.ietf.org/doc/html/rfc9239.
> This document defines equivalent processing requirements for the various script media types. The most widely supported media type in use is `text/javascript`; all others are considered historical and obsolete aliases of `text/javascript`.
* Provide flutter sdk kernel files to dwds launcher instead of dart ones
* Update log test to report all warnings
* Update licences for new files
* Addressed CR comments
* Addressed CR comments
Building an application for a desktop platform that transitively included any Dart-based plugins (such as path_provider) broke `flutter test`, because its compilation was overriding the provided main (in this case, the test main) with `generated_main.dart` if it was present. This PR:
- Changes the `flutter test` compilation path to update `generated_main.dart`, so that the tests will work, and will include any registered Dart plugins.
- Makes using `generated_main.dart` during recompile opt-in, to try to reduce the chance of a similar bug happening with other codepaths in the future.
Fixes https://github.com/flutter/flutter/issues/88794
