[tool] Add --no-minify flag to JS Compiler

packages/flutter_tools/lib/src/commands/build_web.dart

@@ -96,13 +96,22 @@ class BuildWebCommand extends BuildSubCommand {
       help:
           'Passes "--dump-info" to the Javascript compiler which generates '
           'information about the generated code in main.dart.js.info.json.',
+      hide: !verboseHelp,
+    );
+    argParser.addFlag(
+      'minify',
+      help:
+          'Generate minified output. '
+          'If not explicitly set, uses the compilation mode (debug, profile, release).',
+      hide: !verboseHelp,
     );
     argParser.addFlag(
       'no-frequency-based-minification',
       negatable: false,
       help:
           'Disables the frequency based minifier. '
           'Useful for comparing the output between builds.',
+      hide: !verboseHelp,
     );
 
     //
@@ -166,6 +175,7 @@ class BuildWebCommand extends BuildSubCommand {
     );
 
     final bool sourceMaps = boolArg('source-maps');
+    final bool minify = boolArg('minify');
 
     final List<WebCompilerConfig> compilerConfigs;
 
@@ -187,21 +197,23 @@ class BuildWebCommand extends BuildSubCommand {
         ),
         JsCompilerConfig(
           csp: boolArg('csp'),
-          optimizationLevel: jsOptimizationLevel,
           dumpInfo: boolArg('dump-info'),
+          minify: minify,
           nativeNullAssertions: boolArg('native-null-assertions'),
           noFrequencyBasedMinification: boolArg('no-frequency-based-minification'),
+          optimizationLevel: jsOptimizationLevel,
           sourceMaps: sourceMaps,
         ),
       ];
     } else {
       compilerConfigs = <WebCompilerConfig>[
         JsCompilerConfig(
           csp: boolArg('csp'),
-          optimizationLevel: jsOptimizationLevel,
           dumpInfo: boolArg('dump-info'),
+          minify: minify,
           nativeNullAssertions: boolArg('native-null-assertions'),
           noFrequencyBasedMinification: boolArg('no-frequency-based-minification'),
+          optimizationLevel: jsOptimizationLevel,
           sourceMaps: sourceMaps,
           renderer: webRenderer,
         ),

packages/flutter_tools/lib/src/web/compiler_config.dart

@@ -60,6 +60,7 @@ class JsCompilerConfig extends WebCompilerConfig {
     super.optimizationLevel,
     this.noFrequencyBasedMinification = false,
     super.sourceMaps = true,
+    this.minify,
     super.renderer = WebRendererMode.defaultForJs,
   });
 
@@ -75,6 +76,11 @@ class JsCompilerConfig extends WebCompilerConfig {
   /// If `--dump-info` should be passed to the compiler.
   final bool dumpInfo;
 
+  /// If minification should be used in the JS compiler.
+  ///
+  /// If `null`, minifies in release mode only.
+  final bool? minify;
+
   /// Whether native null assertions are enabled.
   final bool nativeNullAssertions;
 
@@ -107,7 +113,7 @@ class JsCompilerConfig extends WebCompilerConfig {
   ///
   /// Includes the contents of [toSharedCommandOptions].
   List<String> toCommandOptions(BuildMode buildMode) => <String>[
-    if (buildMode != BuildMode.release) '--no-minify',
+    if (minify ?? buildMode == BuildMode.release) '--minify' else '--no-minify',
     ...toSharedCommandOptions(buildMode),
     '-O${optimizationLevelForBuildMode(buildMode)}',
     if (dumpInfo) '--stage=dump-info-all',
@@ -123,6 +129,7 @@ class JsCompilerConfig extends WebCompilerConfig {
       'dumpInfo': dumpInfo,
       'nativeNullAssertions': nativeNullAssertions,
       'noFrequencyBasedMinification': noFrequencyBasedMinification,
+      'minify': minify,
       'sourceMaps': sourceMaps,
     };
     return jsonEncode(settings);

packages/flutter_tools/test/commands.shard/hermetic/build_web_test.dart

@@ -547,7 +547,11 @@ void main() {
 
       void expectVisible(String option) {
         expect(command.argParser.options.keys, contains(option));
-        expect(command.argParser.options[option]!.hide, isFalse);
+        expect(
+          command.argParser.options[option]!.hide,
+          isFalse,
+          reason: 'Expecting `$option` to be visible',
+        );
         expect(command.usage, contains(option));
       }
 
@@ -557,8 +561,6 @@ void main() {
       expectVisible('source-maps');
       expectVisible('csp');
       expectVisible('dart2js-optimization');
-      expectVisible('dump-info');
-      expectVisible('no-frequency-based-minification');
       expectVisible('wasm');
       expectVisible('strip-wasm');
       expectVisible('base-href');

packages/flutter_tools/test/general.shard/build_system/targets/web_test.dart

@@ -554,6 +554,47 @@ name: foo
     }, overrides: <Type, Generator>{ProcessManager: () => processManager}),
   );
 
+  test(
+    'Dart2JSTarget calls dart2js with expected args with minify false',
+    () => testbed.run(() async {
+      environment.defines[kBuildMode] = 'release';
+      processManager.addCommand(
+        FakeCommand(
+          command: <String>[
+            ..._kDart2jsLinuxArgs,
+            '-Ddart.vm.product=true',
+            '-DFLUTTER_WEB_USE_SKIA=true',
+            '-DFLUTTER_WEB_USE_SKWASM=false',
+            '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '-o',
+            environment.buildDir.childFile('app.dill').absolute.path,
+            '--packages=/.dart_tool/package_config.json',
+            '--cfe-only',
+            environment.buildDir.childFile('main.dart').absolute.path,
+          ],
+        ),
+      );
+      processManager.addCommand(
+        FakeCommand(
+          command: <String>[
+            ..._kDart2jsLinuxArgs,
+            '-Ddart.vm.product=true',
+            '-DFLUTTER_WEB_USE_SKIA=true',
+            '-DFLUTTER_WEB_USE_SKWASM=false',
+            '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '--no-minify',
+            '-O4',
+            '-o',
+            environment.buildDir.childFile('main.dart.js').absolute.path,
+            environment.buildDir.childFile('app.dill').absolute.path,
+          ],
+        ),
+      );
+
+      await Dart2JSTarget(const JsCompilerConfig(minify: false)).build(environment);
+    }, overrides: <Type, Generator>{ProcessManager: () => processManager}),
+  );
+
   test(
     'Dart2JSTarget ignores frontend server starter path option when calling dart2js',
     () => testbed.run(() async {
@@ -716,6 +757,7 @@ name: foo
             '-DFLUTTER_WEB_USE_SKIA=true',
             '-DFLUTTER_WEB_USE_SKWASM=false',
             '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '--minify',
             '--no-source-maps',
             '-O4',
             '-o',
@@ -759,6 +801,7 @@ name: foo
             '-DFLUTTER_WEB_USE_SKIA=true',
             '-DFLUTTER_WEB_USE_SKWASM=false',
             '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '--minify',
             '--native-null-assertions',
             '--no-source-maps',
             '-O4',
@@ -804,6 +847,7 @@ name: foo
             '-DFLUTTER_WEB_USE_SKIA=true',
             '-DFLUTTER_WEB_USE_SKWASM=false',
             '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '--minify',
             '--no-source-maps',
             '-O3',
             '-o',
@@ -851,6 +895,7 @@ name: foo
             '-DFLUTTER_WEB_USE_SKIA=true',
             '-DFLUTTER_WEB_USE_SKWASM=false',
             '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '--minify',
             '--no-source-maps',
             '-O4',
             '-o',
@@ -909,6 +954,7 @@ name: foo
             '-DFLUTTER_WEB_USE_SKIA=true',
             '-DFLUTTER_WEB_USE_SKWASM=false',
             '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '--minify',
             '--no-source-maps',
             '-O4',
             '-o',
@@ -951,6 +997,7 @@ name: foo
             '-DFLUTTER_WEB_USE_SKIA=true',
             '-DFLUTTER_WEB_USE_SKWASM=false',
             '-DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/abcdefghijklmnopqrstuvwxyz/',
+            '--minify',
             '-O4',
             '-o',
             environment.buildDir.childFile('main.dart.js').absolute.path,
@@ -1251,6 +1298,7 @@ name: foo
       JsCompilerConfig(optimizationLevel: 0),
       JsCompilerConfig(noFrequencyBasedMinification: true),
       JsCompilerConfig(sourceMaps: false),
+      JsCompilerConfig(minify: false),
 
       // All properties non-default
       JsCompilerConfig(