Always require `--local-engine-host` if `--local-engine` (#133003)

Closes #132245.

packages/flutter_tools/lib/src/base/user_messages.dart

@@ -308,12 +308,10 @@ class UserMessages {
       "you have compiled the engine in that directory, which should produce an 'out' directory";
   String get runnerLocalEngineOrWebSdkRequired =>
       'You must specify --local-engine or --local-web-sdk if you are using a locally built engine or web sdk.';
-  // TODO(matanlurey): Make this an error, https://github.com/flutter/flutter/issues/132245.
-  String runnerLocalEngineRequiresHostEngine({bool warning = false}) =>
-      '${warning ? 'Warning! ' : ''}You are using a locally built engine (--local-engine) but have not specified --local-engine-host.\n'
+  String get runnerLocalEngineRequiresHostEngine =>
+      'You are using a locally built engine (--local-engine) but have not specified --local-engine-host.\n'
       'You may be building with a different engine than the one you are running with. '
-      'See https://github.com/flutter/flutter/issues/132245 for details (in the future this will become '
-      'an error).';
+      'See https://github.com/flutter/flutter/issues/132245 for details.';
   String runnerNoEngineBuild(String engineBuildPath) =>
       'No Flutter engine build found at $engineBuildPath.';
   String runnerNoWebSdk(String webSdkPath) =>

packages/flutter_tools/lib/src/context_runner.dart

@@ -276,11 +276,6 @@ Future<T> runInContext<T>(
         platform: globals.platform,
         fileSystem: globals.fs,
         flutterRoot: Cache.flutterRoot!,
-        // TODO(matanlurey): https://github.com/flutter/flutter/issues/132245.
-        // Even though we *think* this feature is stable, we'd like to verify
-        // that automated tests are all providing `--local-engine-host` before
-        // enforcing it for all users.
-        treatMissingLocalEngineHostAsFatal: runningOnBot,
       ),
       Logger: () => globals.platform.isWindows
         ? WindowsStdoutLogger(

packages/flutter_tools/lib/src/runner/local_engine.dart

@@ -33,20 +33,17 @@ class LocalEngineLocator {
     required FileSystem fileSystem,
     required String flutterRoot,
     required UserMessages userMessages,
-    bool treatMissingLocalEngineHostAsFatal = false,
   }) : _platform = platform,
        _logger = logger,
        _fileSystem = fileSystem,
        _flutterRoot = flutterRoot,
-        _userMessages = userMessages,
-        _treatMissingLocalEngineHostAsFatal = treatMissingLocalEngineHostAsFatal;
+        _userMessages = userMessages;
 
   final Platform _platform;
   final Logger _logger;
   final FileSystem _fileSystem;
   final String _flutterRoot;
   final UserMessages _userMessages;
-  final bool _treatMissingLocalEngineHostAsFatal;
 
   /// Returns the engine build path of a local engine if one is located, otherwise `null`.
   Future<EngineBuildPaths?> findEnginePath({
@@ -170,26 +167,6 @@ class LocalEngineLocator {
     return engineSourcePath;
   }
 
-  // Determine the host engine directory associated with the local engine:
-  // Strip '_sim' since there are no host simulator builds.
-  String _getHostEngineBasename(String localEngineBasename) {
-    if (localEngineBasename.startsWith('web_') ||
-        localEngineBasename.startsWith('wasm_') ||
-        localEngineBasename.startsWith('host_')) {
-      // Don't modify the web or host local engine's basename.
-      return localEngineBasename;
-    }
-
-    String tmpBasename = localEngineBasename.replaceFirst('_sim', '');
-    tmpBasename = tmpBasename.substring(tmpBasename.indexOf('_') + 1);
-    // Strip suffix for various archs.
-    const List<String> suffixes = <String>['_arm', '_arm64', '_x86', '_x64'];
-    for (final String suffix in suffixes) {
-      tmpBasename = tmpBasename.replaceFirst(RegExp('$suffix\$'), '');
-    }
-    return 'host_$tmpBasename';
-  }
-
   EngineBuildPaths _findEngineBuildPath({
     required String engineSourcePath,
     String? localEngine,
@@ -209,16 +186,10 @@ class LocalEngineLocator {
       }
 
       if (localHostEngine == null) {
-        // TODO(matanlurey): https://github.com/flutter/flutter/issues/132245, always throwToolExit.
-        if (_treatMissingLocalEngineHostAsFatal) {
-          throwToolExit(_userMessages.runnerLocalEngineRequiresHostEngine());
-        }
-        _logger.printStatus(_userMessages.runnerLocalEngineRequiresHostEngine(warning: true));
+        throwToolExit(_userMessages.runnerLocalEngineRequiresHostEngine);
       }
-      final String basename = localHostEngine ?? _fileSystem.path.basename(engineBuildPath);
-      final String hostBasename = _getHostEngineBasename(basename);
       engineHostBuildPath = _fileSystem.path.normalize(
-        _fileSystem.path.join(_fileSystem.path.dirname(engineBuildPath), hostBasename),
+        _fileSystem.path.join(_fileSystem.path.dirname(engineBuildPath), localHostEngine),
       );
       if (!_fileSystem.isDirectorySync(engineHostBuildPath)) {
         throwToolExit(_userMessages.runnerNoEngineBuild(engineHostBuildPath), exitCode: 2);

packages/flutter_tools/test/general.shard/runner/local_engine_test.dart

@@ -43,7 +43,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: 'ios_debug'),
+      await localEngineLocator.findEnginePath(localEngine: 'ios_debug', localHostEngine: 'host_debug'),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/host_debug',
         targetEngine: '/arbitrary/engine/src/out/ios_debug',
@@ -58,7 +58,7 @@ void main() {
       .writeAsStringSync('sky_engine:file:///symlink/src/out/ios_debug/gen/dart-pkg/sky_engine/lib/');
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: 'ios_debug'),
+      await localEngineLocator.findEnginePath(localEngine: 'ios_debug', localHostEngine: 'host_debug'),
       matchesEngineBuildPaths(
         hostEngine: '/symlink/src/out/host_debug',
         targetEngine: '/symlink/src/out/ios_debug',
@@ -84,7 +84,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(engineSourcePath: '$kArbitraryEngineRoot/src', localEngine: 'ios_debug'),
+      await localEngineLocator.findEnginePath(engineSourcePath: '$kArbitraryEngineRoot/src', localEngine: 'ios_debug', localHostEngine: 'host_debug'),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/host_debug',
         targetEngine: '/arbitrary/engine/src/out/ios_debug',
@@ -119,7 +119,7 @@ void main() {
     expect(logger.traceText, contains('Local engine source at /arbitrary/engine/src'));
   });
 
-  testWithoutContext('works but produces a warning if --local-engine is specified but not --local-engine-host', () async {
+  testWithoutContext('fails if --local-engine-host is omitted', () async {
     final FileSystem fileSystem = MemoryFileSystem.test();
     final Directory localEngine = fileSystem
         .directory('$kArbitraryEngineRoot/src/out/android_debug_unopt_arm64/')
@@ -135,33 +135,6 @@ void main() {
       platform: FakePlatform(environment: <String, String>{}),
     );
 
-    expect(
-      await localEngineLocator.findEnginePath(localEngine: localEngine.path),
-      matchesEngineBuildPaths(
-        hostEngine: '/arbitrary/engine/src/out/host_debug_unopt',
-        targetEngine: '/arbitrary/engine/src/out/android_debug_unopt_arm64',
-      ),
-    );
-    expect(logger.statusText, contains('Warning! You are using a locally built engine (--local-engine) but have not specified --local-engine-host'));
-  });
-
-  testWithoutContext('fails if --local-engine-host is emitted and treatMissingLocalEngineHostAsFatal is set', () async {
-    final FileSystem fileSystem = MemoryFileSystem.test();
-    final Directory localEngine = fileSystem
-        .directory('$kArbitraryEngineRoot/src/out/android_debug_unopt_arm64/')
-        ..createSync(recursive: true);
-    fileSystem.directory('$kArbitraryEngineRoot/src/out/host_debug_unopt/').createSync(recursive: true);
-
-    final BufferLogger logger = BufferLogger.test();
-    final LocalEngineLocator localEngineLocator = LocalEngineLocator(
-      fileSystem: fileSystem,
-      flutterRoot: 'flutter/flutter',
-      logger: logger,
-      userMessages: UserMessages(),
-      platform: FakePlatform(environment: <String, String>{}),
-      treatMissingLocalEngineHostAsFatal: true,
-    );
-
     await expectLater(
       localEngineLocator.findEnginePath(localEngine: localEngine.path),
       throwsToolExit(message: 'You are using a locally built engine (--local-engine) but have not specified --local-engine-host'),
@@ -186,7 +159,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: localEngine.path),
+      await localEngineLocator.findEnginePath(localEngine: localEngine.path, localHostEngine: 'host_debug'),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/host_debug',
         targetEngine: '/arbitrary/engine/src/out/ios_debug',
@@ -212,7 +185,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: localEngine.path),
+      await localEngineLocator.findEnginePath(localEngine: localEngine.path, localHostEngine: localEngine.path),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/host_debug',
         targetEngine: '/arbitrary/engine/src/out/host_debug',
@@ -237,7 +210,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: localEngine.path),
+      await localEngineLocator.findEnginePath(localEngine: localEngine.path, localHostEngine: localEngine.path),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/host_debug_unopt_arm64',
         targetEngine: '/arbitrary/engine/src/out/host_debug_unopt_arm64',
@@ -264,7 +237,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: localEngine.path),
+      await localEngineLocator.findEnginePath(localEngine: localEngine.path, localHostEngine: 'host_debug'),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/host_debug',
         targetEngine: '/arbitrary/engine/src/out/ios_debug_sim',
@@ -292,7 +265,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: localEngine.path),
+      await localEngineLocator.findEnginePath(localEngine: localEngine.path, localHostEngine: 'host_debug_unopt'),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/host_debug_unopt',
         targetEngine: '/arbitrary/engine/src/out/ios_debug_sim_unopt',
@@ -315,7 +288,7 @@ void main() {
     );
 
     await expectToolExitLater(
-      localEngineLocator.findEnginePath(localEngine: localEngine.path),
+      localEngineLocator.findEnginePath(localEngine: localEngine.path, localHostEngine: 'host_debug'),
       contains('No Flutter engine build found at /arbitrary/engine/src/out/host_debug'),
     );
   });
@@ -344,7 +317,7 @@ void main() {
     );
 
     expect(
-      await localEngineLocator.findEnginePath(localEngine: 'ios_debug'),
+      await localEngineLocator.findEnginePath(localEngine: 'ios_debug', localHostEngine: 'host_debug'),
       matchesEngineBuildPaths(
         hostEngine: 'flutter/engine/src/out/host_debug',
         targetEngine: 'flutter/engine/src/out/ios_debug',
@@ -366,7 +339,7 @@ void main() {
     );
 
     await expectToolExitLater(
-      localEngineLocator.findEnginePath(localEngine: '/path/to/nothing'),
+      localEngineLocator.findEnginePath(localEngine: '/path/to/nothing', localHostEngine: '/path/to/nothing'),
       contains('Unable to detect local Flutter engine src directory'),
     );
   });
@@ -390,7 +363,7 @@ void main() {
     );
 
     expect(
-      await localWasmEngineLocator.findEnginePath(localEngine: localWasmEngine.path),
+      await localWasmEngineLocator.findEnginePath(localEngine: localWasmEngine.path, localHostEngine: localWasmEngine.path),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/wasm_whatever',
         targetEngine: '/arbitrary/engine/src/out/wasm_whatever',
@@ -408,7 +381,7 @@ void main() {
     );
 
     expect(
-      await localWebEngineLocator.findEnginePath(localEngine: localWebEngine.path),
+      await localWebEngineLocator.findEnginePath(localEngine: localWebEngine.path, localHostEngine: localWebEngine.path),
       matchesEngineBuildPaths(
         hostEngine: '/arbitrary/engine/src/out/web_whatever',
         targetEngine: '/arbitrary/engine/src/out/web_whatever',