Add --canary option to build web compilers (#3536)

* Add --canary option to build web compilers

* Prepare to release build_web_compilers

* Update pubspec and build

Author: Anna Gringauze

build_web_compilers/CHANGELOG.md

@@ -1,4 +1,19 @@
-## 4.0.4-wip
+## 4.0.4
+
+- Add the `canary` option for `build_web_compilers:ddc` and
+  `build_web_compilers:sdk_js`builders to enable canary features
+  in DDC. This setting is disabled by default but can be enabled
+  by setting it to `true` globally:
+
+```yaml
+global_options:
+  build_web_compilers:ddc:
+    options:
+      canary: true
+  build_web_compilers:sdk_js:
+    options:
+      canary: true
+```
 
 ## 4.0.3
 

build_web_compilers/lib/builders.dart

@@ -29,6 +29,7 @@ Builder ddcBuilder(BuilderOptions options) {
     useIncrementalCompiler: _readUseIncrementalCompilerOption(options),
     generateFullDill: _readGenerateFullDillOption(options),
     emitDebugSymbols: _readEmitDebugSymbolsOption(options),
+    canaryFeatures: _readCanaryOption(options),
     sdkKernelPath: sdkDdcKernelPath,
     trackUnusedInputs: _readTrackInputsCompilerOption(options),
     platform: ddcPlatform,
@@ -52,9 +53,11 @@ Builder ddcKernelBuilder(BuilderOptions options) {
 }
 
 Builder sdkJsCopyRequirejs(_) => SdkJsCopyBuilder();
-Builder sdkJsCompile(_) => SdkJsCompileBuilder(
-    sdkKernelPath: 'lib/_internal/ddc_platform.dill',
-    outputPath: 'lib/src/dev_compiler/dart_sdk.js');
+Builder sdkJsCompile(BuilderOptions options) => SdkJsCompileBuilder(
+      sdkKernelPath: 'lib/_internal/ddc_platform.dill',
+      outputPath: 'lib/src/dev_compiler/dart_sdk.js',
+      canaryFeatures: _readCanaryOption(options),
+    );
 
 // Dart2js related builders
 Builder dart2jsMetaModuleBuilder(BuilderOptions options) =>
@@ -102,6 +105,10 @@ bool _readEmitDebugSymbolsOption(BuilderOptions options) {
   return options.config[_emitDebugSymbolsOption] as bool? ?? false;
 }
 
+bool _readCanaryOption(BuilderOptions options) {
+  return options.config[_canaryOption] as bool? ?? false;
+}
+
 bool _readTrackInputsCompilerOption(BuilderOptions options) {
   return options.config[_trackUnusedInputsCompilerOption] as bool? ?? true;
 }
@@ -115,6 +122,7 @@ Map<String, dynamic>? _previousDdcConfig;
 const _useIncrementalCompilerOption = 'use-incremental-compiler';
 const _generateFullDillOption = 'generate-full-dill';
 const _emitDebugSymbolsOption = 'emit-debug-symbols';
+const _canaryOption = 'canary';
 const _trackUnusedInputsCompilerOption = 'track-unused-inputs';
 const _environmentOption = 'environment';
 
@@ -123,5 +131,6 @@ const _supportedOptions = [
   _useIncrementalCompilerOption,
   _generateFullDillOption,
   _emitDebugSymbolsOption,
+  _canaryOption,
   _trackUnusedInputsCompilerOption,
 ];

build_web_compilers/lib/src/dev_compiler_builder.dart

@@ -47,6 +47,9 @@ class DevCompilerBuilder implements Builder {
   /// watch, expression evaluation, and variable inspection windows.
   final bool emitDebugSymbols;
 
+  /// Enables canary features in DDC.
+  final bool canaryFeatures;
+
   final bool trackUnusedInputs;
 
   final DartPlatform platform;
@@ -75,6 +78,7 @@ class DevCompilerBuilder implements Builder {
       {this.useIncrementalCompiler = true,
       this.generateFullDill = false,
       this.emitDebugSymbols = false,
+      this.canaryFeatures = false,
       this.trackUnusedInputs = false,
       required this.platform,
       String? sdkKernelPath,
@@ -124,6 +128,7 @@ class DevCompilerBuilder implements Builder {
           useIncrementalCompiler,
           generateFullDill,
           emitDebugSymbols,
+          canaryFeatures,
           trackUnusedInputs,
           platformSdk,
           sdkKernelPath,
@@ -144,6 +149,7 @@ Future<void> _createDevCompilerModule(
     bool useIncrementalCompiler,
     bool generateFullDill,
     bool emitDebugSymbols,
+    bool canaryFeatures,
     bool trackUnusedInputs,
     String dartSdk,
     String sdkKernelPath,
@@ -188,6 +194,7 @@ Future<void> _createDevCompilerModule(
       '--no-summarize',
       if (generateFullDill) '--experimental-output-compiled-kernel',
       if (emitDebugSymbols) '--emit-debug-symbols',
+      if (canaryFeatures) '--canary',
       '-o',
       jsOutputFile.path,
       debugMode ? '--source-map' : '--no-source-map',