[flutter_plugin_tools] If clang-format does not run, fall back to other executables in PATH (flutter#6853)

* If clang-format does not run, fall back to other executables in PATH

* Review edits

Author: jmagman

script/tool/CHANGELOG.md

@@ -1,4 +1,8 @@
-## 13.1
+## 0.13.2
+
+* Falls back to other executables in PATH when `clang-format` does not run.
+
+## 0.13.1
 
 * Updates `version-check` to recognize Pigeon's platform test structure.
 * Pins `package:git` dependency to `2.0.x` until `dart >=2.18.0` becomes our

script/tool/lib/src/create_all_packages_app_command.dart

@@ -230,7 +230,7 @@ class CreateAllPackagesAppCommand extends PackageCommand {
 
   String _pubspecToString(Pubspec pubspec) {
     return '''
-### Generated file. Do not edit. Run `pub global run flutter_plugin_tools gen-pubspec` to update.
+### Generated file. Do not edit. Run `dart pub global run flutter_plugin_tools gen-pubspec` to update.
 name: ${pubspec.name}
 description: ${pubspec.description}
 publish_to: none

script/tool/lib/src/format_command.dart

@@ -104,8 +104,8 @@ class FormatCommand extends PackageCommand {
     print('These files are not formatted correctly (see diff below):');
     LineSplitter.split(stdout).map((String line) => '  $line').forEach(print);
 
-    print('\nTo fix run "pub global activate flutter_plugin_tools && '
-        'pub global run flutter_plugin_tools format" or copy-paste '
+    print('\nTo fix run "dart pub global activate flutter_plugin_tools && '
+        'dart pub global run flutter_plugin_tools format" or copy-paste '
         'this command into your terminal:');
 
     final io.ProcessResult diff = await processRunner.run(
@@ -128,16 +128,11 @@ class FormatCommand extends PackageCommand {
     final Iterable<String> clangFiles = _getPathsWithExtensions(
         files, <String>{'.h', '.m', '.mm', '.cc', '.cpp'});
     if (clangFiles.isNotEmpty) {
-      final String clangFormat = getStringArg('clang-format');
-      if (!await _hasDependency(clangFormat)) {
-        printError('Unable to run "clang-format". Make sure that it is in your '
-            'path, or provide a full path with --clang-format.');
-        throw ToolExit(_exitDependencyMissing);
-      }
+      final String clangFormat = await _findValidClangFormat();
 
       print('Formatting .cc, .cpp, .h, .m, and .mm files...');
       final int exitCode = await _runBatched(
-          getStringArg('clang-format'), <String>['-i', '--style=file'],
+          clangFormat, <String>['-i', '--style=file'],
           files: clangFiles);
       if (exitCode != 0) {
         printError(
@@ -147,6 +142,26 @@ class FormatCommand extends PackageCommand {
     }
   }
 
+  Future<String> _findValidClangFormat() async {
+    final String clangFormatArg = getStringArg('clang-format');
+    if (await _hasDependency(clangFormatArg)) {
+      return clangFormatArg;
+    }
+
+    // There is a known issue where "chromium/depot_tools/clang-format"
+    // fails with "Problem while looking for clang-format in Chromium source tree".
+    // Loop through all "clang-format"s in PATH until a working one is found,
+    // for example "/usr/local/bin/clang-format" or a "brew" installed version.
+    for (final String clangFormatPath in await _whichAll('clang-format')) {
+      if (await _hasDependency(clangFormatPath)) {
+        return clangFormatPath;
+      }
+    }
+    printError('Unable to run "clang-format". Make sure that it is in your '
+        'path, or provide a full path with --clang-format.');
+    throw ToolExit(_exitDependencyMissing);
+  }
+
   Future<void> _formatJava(
       Iterable<String> files, String googleFormatterPath) async {
     final Iterable<String> javaFiles =
@@ -279,6 +294,26 @@ class FormatCommand extends PackageCommand {
     return true;
   }
 
+  /// Returns all instances of [command] executable found on user path.
+  Future<List<String>> _whichAll(String command) async {
+    try {
+      final io.ProcessResult result =
+      await processRunner.run('which', <String>['-a', command]);
+
+      if (result.exitCode != 0) {
+        return <String>[];
+      }
+
+      final String stdout = result.stdout.trim() as String;
+      if (stdout.isEmpty) {
+        return <String>[];
+      }
+      return LineSplitter.split(stdout).toList();
+    } on io.ProcessException {
+      return <String>[];
+    }
+  }
+
   /// Runs [command] on [arguments] on all of the files in [files], batched as
   /// necessary to avoid OS command-line length limits.
   ///

script/tool/lib/src/main.dart

@@ -52,7 +52,7 @@ void main(List<String> args) {
   }
 
   final CommandRunner<void> commandRunner = CommandRunner<void>(
-      'pub global run flutter_plugin_tools',
+      'dart pub global run flutter_plugin_tools',
       'Productivity utils for hosting multiple plugins within one repository.')
     ..addCommand(AnalyzeCommand(packagesDir))
     ..addCommand(BuildExamplesCommand(packagesDir))

script/tool/pubspec.yaml

@@ -1,7 +1,7 @@
 name: flutter_plugin_tools
 description: Productivity utils for flutter/plugins and flutter/packages
 repository: https://github.com/flutter/plugins/tree/main/script/tool
-version: 0.13.1
+version: 0.13.2
 
 dependencies:
   args: ^2.1.0

script/tool/test/format_command_test.dart

@@ -332,6 +332,44 @@ void main() {
         ]));
   });
 
+  test('falls back to working clang-format in the path', () async {
+    const List<String> files = <String>[
+      'linux/foo_plugin.cc',
+      'macos/Classes/Foo.h',
+    ];
+    final RepositoryPackage plugin = createFakePlugin(
+      'a_plugin',
+      packagesDir,
+      extraFiles: files,
+    );
+
+    processRunner.mockProcessesForExecutable['clang-format'] = <io.Process>[
+      MockProcess(exitCode: 1)
+    ];
+    processRunner.mockProcessesForExecutable['which'] = <io.Process>[
+      MockProcess(
+          stdout: '/usr/local/bin/clang-format\n/path/to/working-clang-format')
+    ];
+    processRunner.mockProcessesForExecutable['/usr/local/bin/clang-format'] =
+        <io.Process>[MockProcess(exitCode: 1)];
+    await runCapturingPrint(runner, <String>['format']);
+
+    expect(
+        processRunner.recordedCalls,
+        containsAll(<ProcessCall>[
+          const ProcessCall(
+              '/path/to/working-clang-format', <String>['--version'], null),
+          ProcessCall(
+              '/path/to/working-clang-format',
+              <String>[
+                '-i',
+                '--style=file',
+                ...getPackagesDirRelativePaths(plugin, files)
+              ],
+              packagesDir.path),
+        ]));
+  });
+
   test('honors --clang-format flag', () async {
     const List<String> files = <String>[
       'windows/foo_plugin.cpp',