Don't remove toString implementations while in debug mode. (#154216)

This matches the behavior of AOT/VM compilation.

Author: eyebrowsoffire

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

@@ -284,6 +284,36 @@ class Dart2WasmTarget extends Dart2WebTarget {
   @override
   final WasmCompilerConfig compilerConfig;
 
+  /// List the preconfigured build options for a given build mode.
+  List<String> buildModeOptions(BuildMode mode, List<String> dartDefines) =>
+    switch (mode) {
+      BuildMode.debug => <String>[
+          // These checks allow the CLI to override the value of this define for unit
+          // testing the framework.
+          if (!dartDefines.any((String define) => define.startsWith('dart.vm.profile')))
+            '-Ddart.vm.profile=false',
+          if (!dartDefines.any((String define) => define.startsWith('dart.vm.product')))
+            '-Ddart.vm.product=false',
+        ],
+      BuildMode.profile => <String>[
+          // These checks allow the CLI to override the value of this define for
+          // benchmarks with most timeline traces disabled.
+          if (!dartDefines.any((String define) => define.startsWith('dart.vm.profile')))
+            '-Ddart.vm.profile=true',
+          if (!dartDefines.any((String define) => define.startsWith('dart.vm.product')))
+            '-Ddart.vm.product=false',
+          '--extra-compiler-option=--delete-tostring-package-uri=dart:ui',
+          '--extra-compiler-option=--delete-tostring-package-uri=package:flutter',
+        ],
+      BuildMode.release => <String>[
+          '-Ddart.vm.profile=false',
+          '-Ddart.vm.product=true',
+          '--extra-compiler-option=--delete-tostring-package-uri=dart:ui',
+          '--extra-compiler-option=--delete-tostring-package-uri=package:flutter',
+        ],
+      _ => throw Exception('Unknown BuildMode: $mode')
+    };
+
   @override
   Future<void> build(Environment environment) async {
     final String? buildModeEnvironment = environment.defines[kBuildMode];
@@ -297,25 +327,21 @@ class Dart2WasmTarget extends Dart2WebTarget {
     final File depFile = environment.buildDir.childFile('dart2wasm.d');
     final String platformBinariesPath = artifacts.getHostArtifact(HostArtifact.webPlatformKernelFolder).path;
     final String platformFilePath = environment.fileSystem.path.join(platformBinariesPath, 'dart2wasm_platform.dill');
+    final List<String> dartDefines = computeDartDefines(environment);
 
     final List<String> compilationArgs = <String>[
       artifacts.getArtifactPath(Artifact.engineDartBinary, platform: TargetPlatform.web_javascript),
       'compile',
       'wasm',
       '--packages=${findPackageConfigFileOrDefault(environment.projectDir).path}',
       '--extra-compiler-option=--platform=$platformFilePath',
-      '--extra-compiler-option=--delete-tostring-package-uri=dart:ui',
-      '--extra-compiler-option=--delete-tostring-package-uri=package:flutter',
+      ...buildModeOptions(buildMode, dartDefines),
       if (compilerConfig.renderer == WebRendererMode.skwasm) ...<String>[
         '--extra-compiler-option=--import-shared-memory',
         '--extra-compiler-option=--shared-memory-max-pages=32768',
       ],
-      if (buildMode == BuildMode.profile)
-        '-Ddart.vm.profile=true'
-      else if (buildMode == BuildMode.release)
-        '-Ddart.vm.product=true',
       ...decodeCommaSeparated(environment.defines, kExtraFrontEndOptions),
-      for (final String dartDefine in computeDartDefines(environment))
+      for (final String dartDefine in dartDefines)
         '-D$dartDefine',
       '--extra-compiler-option=--depfile=${depFile.path}',
 

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

@@ -35,8 +35,6 @@ const List<String> _kDart2WasmLinuxArgs = <String> [
   'wasm',
   '--packages=/.dart_tool/package_config.json',
   '--extra-compiler-option=--platform=HostArtifact.webPlatformKernelFolder/dart2wasm_platform.dill',
-  '--extra-compiler-option=--delete-tostring-package-uri=dart:ui',
-  '--extra-compiler-option=--delete-tostring-package-uri=package:flutter',
 ];
 
 void main() {
@@ -1034,12 +1032,16 @@ void main() {
                 processManager.addCommand(FakeCommand(
                   command: <String>[
                     ..._kDart2WasmLinuxArgs,
+                    '-Ddart.vm.profile=${buildMode == 'profile'}',
+                    '-Ddart.vm.product=${buildMode == 'release'}',
+                    if (buildMode != 'debug') ...<String>[
+                      '--extra-compiler-option=--delete-tostring-package-uri=dart:ui',
+                      '--extra-compiler-option=--delete-tostring-package-uri=package:flutter',
+                    ],
                     if (renderer == WebRendererMode.skwasm) ...<String>[
                       '--extra-compiler-option=--import-shared-memory',
                       '--extra-compiler-option=--shared-memory-max-pages=32768',
                     ],
-                    if (buildMode != 'debug')
-                      '-Ddart.vm.${buildMode == 'release' ? 'product' : 'profile' }=true',
                     ...defines.map((String define) => '-D$define'),
                     if (renderer == WebRendererMode.skwasm) ...<String>[
                       '-DFLUTTER_WEB_AUTO_DETECT=false',