[flutter_tools] Concise dart2js commands outputKernel & outputJavaScript (#61881)

packages/flutter_tools/lib/src/build_system/targets/web.dart

@@ -153,64 +153,48 @@ class Dart2JSTarget extends Target {
 
   @override
   Future<void> build(Environment environment) async {
-    final String dart2jsOptimization = environment.defines[kDart2jsOptimization];
-    final bool csp = environment.defines[kCspMode] == 'true';
     final BuildMode buildMode = getBuildModeForName(environment.defines[kBuildMode]);
-    final String specPath = globals.fs.path.join(
-      globals.artifacts.getArtifactPath(Artifact.flutterWebSdk), 'libraries.json');
-    // TODO(jonahwilliams): support configuration of this file.
-    const String packageFile = '.packages';
-    final File outputKernel = environment.buildDir.childFile('app.dill');
-    final File outputFile = environment.buildDir.childFile('main.dart.js');
-    final List<String> dartDefines = decodeDartDefines(environment.defines, kDartDefines);
-    final List<String> extraFrontEndOptions = decodeDartDefines(environment.defines, kExtraFrontEndOptions);
 
-    // Run the dart2js compilation in two stages, so that icon tree shaking can
-    // parse the kernel file for web builds.
-    final ProcessResult kernelResult = await globals.processManager.run(<String>[
+    final List<String> sharedCommandOptions = <String>[
       globals.artifacts.getArtifactPath(Artifact.engineDartBinary),
       '--disable-dart-dev',
       globals.artifacts.getArtifactPath(Artifact.dart2jsSnapshot),
-      '--libraries-spec=$specPath',
-      ...?extraFrontEndOptions,
-      '-o',
-      outputKernel.path,
-      '--packages=$packageFile',
+      '--libraries-spec=${globals.fs.path.join(globals.artifacts.getArtifactPath(Artifact.flutterWebSdk), 'libraries.json')}',
+      ...?decodeDartDefines(environment.defines, kExtraFrontEndOptions),
       if (buildMode == BuildMode.profile)
         '-Ddart.vm.profile=true'
       else
         '-Ddart.vm.product=true',
-      for (final String dartDefine in dartDefines)
+      for (final String dartDefine in decodeDartDefines(environment.defines, kDartDefines))
         '-D$dartDefine',
+    ];
+
+    // Run the dart2js compilation in two stages, so that icon tree shaking can
+    // parse the kernel file for web builds.
+    final ProcessResult kernelResult = await globals.processManager.run(<String>[
+      ...sharedCommandOptions,
+      '-o',
+      environment.buildDir.childFile('app.dill').path,
+      '--packages=.packages',
       '--cfe-only',
-      environment.buildDir.childFile('main.dart').path,
+      environment.buildDir.childFile('main.dart').path, // dartfile
     ]);
     if (kernelResult.exitCode != 0) {
       throw Exception(kernelResult.stdout + kernelResult.stderr);
     }
+
+    final String dart2jsOptimization = environment.defines[kDart2jsOptimization];
+    final File outputJSFile = environment.buildDir.childFile('main.dart.js');
+    final bool csp = environment.defines[kCspMode] == 'true';
+
     final ProcessResult javaScriptResult = await globals.processManager.run(<String>[
-      globals.artifacts.getArtifactPath(Artifact.engineDartBinary),
-      '--disable-dart-dev',
-      globals.artifacts.getArtifactPath(Artifact.dart2jsSnapshot),
-      '--libraries-spec=$specPath',
-      ...?extraFrontEndOptions,
-      if (dart2jsOptimization != null)
-        '-$dart2jsOptimization'
-      else
-        '-O4',
-      if (buildMode == BuildMode.profile)
-        '-Ddart.vm.profile=true'
-      else
-        '-Ddart.vm.product=true',
-      for (final String dartDefine in dartDefines)
-        '-D$dartDefine',
-      if (buildMode == BuildMode.profile)
-        '--no-minify',
-      if (csp)
-        '--csp',
+      ...sharedCommandOptions,
+      if (dart2jsOptimization != null) '-$dart2jsOptimization' else '-O4',
+      if (buildMode == BuildMode.profile) '--no-minify',
+      if (csp) '--csp',
       '-o',
-      outputFile.path,
-      environment.buildDir.childFile('app.dill').path,
+      outputJSFile.path,
+      environment.buildDir.childFile('app.dill').path, // dartfile
     ]);
     if (javaScriptResult.exitCode != 0) {
       throw Exception(javaScriptResult.stdout + javaScriptResult.stderr);
@@ -228,7 +212,7 @@ class Dart2JSTarget extends Target {
     );
     final Depfile depfile = depfileService.parseDart2js(
       environment.buildDir.childFile('app.dill.deps'),
-      outputFile,
+      outputJSFile,
     );
     depfileService.writeToFile(
       depfile,

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

@@ -225,10 +225,10 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
+        '-Ddart.vm.profile=true',
         '-o',
         environment.buildDir.childFile('app.dill').absolute.path,
         '--packages=.packages',
-        '-Ddart.vm.profile=true',
         '--cfe-only',
         environment.buildDir.childFile('main.dart').absolute.path,
       ]
@@ -236,8 +236,8 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-O4',
         '-Ddart.vm.profile=true',
+        '-O4',
         '--no-minify',
         '--csp',
         '-o',
@@ -259,10 +259,10 @@ void main() {
       command: <String>[
         ...kDart2jsLinuxArgs,
         '--enable-experiment=non-nullable',
+        '-Ddart.vm.profile=true',
         '-o',
         environment.buildDir.childFile('app.dill').absolute.path,
         '--packages=.packages',
-        '-Ddart.vm.profile=true',
         '--cfe-only',
         environment.buildDir.childFile('main.dart').absolute.path,
       ]
@@ -271,8 +271,8 @@ void main() {
       command: <String>[
         ...kDart2jsLinuxArgs,
         '--enable-experiment=non-nullable',
-        '-O4',
         '-Ddart.vm.profile=true',
+        '-O4',
         '--no-minify',
         '-o',
         environment.buildDir.childFile('main.dart.js').absolute.path,
@@ -290,10 +290,10 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
+        '-Ddart.vm.profile=true',
         '-o',
         environment.buildDir.childFile('app.dill').absolute.path,
         '--packages=.packages',
-        '-Ddart.vm.profile=true',
         '--cfe-only',
         environment.buildDir.childFile('main.dart').absolute.path,
       ]
@@ -301,8 +301,8 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-O4',
         '-Ddart.vm.profile=true',
+        '-O4',
         '--no-minify',
         '-o',
         environment.buildDir.childFile('main.dart.js').absolute.path,
@@ -320,10 +320,10 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
+        '-Ddart.vm.product=true',
         '-o',
         environment.buildDir.childFile('app.dill').absolute.path,
         '--packages=.packages',
-        '-Ddart.vm.product=true',
         '--cfe-only',
         environment.buildDir.childFile('main.dart').absolute.path,
       ]
@@ -331,8 +331,8 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-O4',
         '-Ddart.vm.product=true',
+        '-O4',
         '-o',
         environment.buildDir.childFile('main.dart.js').absolute.path,
         environment.buildDir.childFile('app.dill').absolute.path,
@@ -350,10 +350,10 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
+        '-Ddart.vm.product=true',
         '-o',
         environment.buildDir.childFile('app.dill').absolute.path,
         '--packages=.packages',
-        '-Ddart.vm.product=true',
         '--cfe-only',
         environment.buildDir.childFile('main.dart').absolute.path,
       ]
@@ -361,8 +361,8 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-O3',
         '-Ddart.vm.product=true',
+        '-O3',
         '-o',
         environment.buildDir.childFile('main.dart.js').absolute.path,
         environment.buildDir.childFile('app.dill').absolute.path,
@@ -399,12 +399,12 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-o',
-        environment.buildDir.childFile('app.dill').absolute.path,
-        '--packages=.packages',
         '-Ddart.vm.product=true',
         '-DFOO=bar',
         '-DBAZ=qux',
+        '-o',
+        environment.buildDir.childFile('app.dill').absolute.path,
+        '--packages=.packages',
        '--cfe-only',
         environment.buildDir.childFile('main.dart').absolute.path,
       ]
@@ -412,10 +412,10 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-O4',
         '-Ddart.vm.product=true',
         '-DFOO=bar',
         '-DBAZ=qux',
+        '-O4',
         '-o',
         environment.buildDir.childFile('main.dart.js').absolute.path,
         environment.buildDir.childFile('app.dill').absolute.path,
@@ -433,12 +433,12 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-o',
-        environment.buildDir.childFile('app.dill').absolute.path,
-        '--packages=.packages',
         '-Ddart.vm.profile=true',
         '-DFOO=bar',
         '-DBAZ=qux',
+        '-o',
+        environment.buildDir.childFile('app.dill').absolute.path,
+        '--packages=.packages',
         '--cfe-only',
         environment.buildDir.childFile('main.dart').absolute.path,
       ]
@@ -446,10 +446,10 @@ void main() {
     processManager.addCommand(FakeCommand(
       command: <String>[
         ...kDart2jsLinuxArgs,
-        '-O4',
         '-Ddart.vm.profile=true',
         '-DFOO=bar',
         '-DBAZ=qux',
+        '-O4',
         '--no-minify',
         '-o',
         environment.buildDir.childFile('main.dart.js').absolute.path,