[camera_android_camerax][tool] Integrate dart_code_linter for cyclomatic complexity checks

.repo_tool_config.yaml

@@ -20,6 +20,9 @@ allowed_dependencies:
   # A pin can be either an exact version, or a range with an explicit, inclusive
   # max version, which must a version that already exists, not a future version.
   pinned:
+    # Cyclomatic complexity linter for camera_android_camerax
+    - dart_code_linter
+
     # Test-only dependency, so does not impact package clients, and
     # has limited impact so could be easily removed if there are
     # ever maintenance issues in the future.

packages/camera/camera_android_camerax/analysis_options.yaml

@@ -0,0 +1,16 @@
+include: ../../../analysis_options.yaml
+
+analyzer:
+  exclude:
+    - build/**
+    - android/**
+    - ios/**
+    - web/**
+    - windows/**
+    - macos/**
+    - linux/**
+
+dart_code_linter:
+  metrics:
+    cyclomatic-complexity: 15
+

packages/camera/camera_android_camerax/pubspec.yaml

@@ -27,6 +27,7 @@ dependencies:
 
 dev_dependencies:
   build_runner: ^2.2.0
+  dart_code_linter: 4.1.5
   dart_skills_lint:
     git:
       url: https://github.com/flutter/skills.git

script/configs/custom_analysis.yaml

@@ -34,3 +34,6 @@
 - rfw/example
 # Disables docs requirements, as it is test code.
 - web_benchmarks/testing/test_app
+# Uses custom analysis to enable the cognitive complexity linter plugin.
+- camera/camera_android_camerax
+

script/tool/lib/src/analyze_command.dart

@@ -313,6 +313,53 @@ class AnalyzeCommand extends PackageLoopingCommand {
     if (exitCode != 0) {
       return PackageResult.fail();
     }
+
+    final customCheckRunners = <_CustomLinter>[
+      _CustomLinter(
+        dependencyName: 'dart_code_linter',
+        run: _runDartCodeLinterForPackage,
+      ),
+    ];
+
+    final Pubspec pubspec = package.parsePubspec();
+    for (final runner in customCheckRunners) {
+      final bool hasDependency = pubspec.devDependencies.containsKey(runner.dependencyName);
+      if (hasDependency) {
+        final PackageResult result = await runner.run(package);
+        if (result.state == RunState.failed) {
+          return result;
+        }
+      }
+    }
+
+    return PackageResult.success();
+  }
+
+  /// Runs the `dart_code_linter` metrics analyzer on the package.
+  ///
+  /// Assumes `dart_code_linter` is present in `dev_dependencies`.
+  Future<PackageResult> _runDartCodeLinterForPackage(RepositoryPackage package) async {
+    print('Running dart_code_linter:metrics analysis...');
+    final bool isFlutter = package.requiresFlutter();
+    final String sdkCommand = isFlutter ? flutterCommand : _dartBinaryPath;
+    final int linterExitCode = await processRunner.runAndStream(
+      sdkCommand,
+      <String>[
+        if (isFlutter) 'pub',
+        'run',
+        'dart_code_linter:metrics',
+        'analyze',
+        'lib',
+        '--set-exit-on-violation-level=warning',
+      ],
+      workingDir: package.directory,
+    );
+    if (linterExitCode != 0) {
+      return PackageResult.fail(<String>[
+        'Metrics violations found. See the package\'s local "analysis_options.yaml" for configured thresholds.'
+      ]);
+    }
+
     return PackageResult.success();
   }
 
@@ -437,3 +484,20 @@ class AnalyzeCommand extends PackageLoopingCommand {
     return errors.isEmpty ? PackageResult.success() : PackageResult.fail(errors);
   }
 }
+
+/// Represents a custom linter check that is executed during package analysis.
+class _CustomLinter {
+  const _CustomLinter({
+    required this.dependencyName,
+    required this.run,
+  });
+
+  /// The name of the package dependency that triggers this custom check.
+  ///
+  /// The check is only executed if this dependency is listed in the package's
+  /// `dev_dependencies`.
+  final String dependencyName;
+
+  /// The runner function that executes the custom check.
+  final Future<PackageResult> Function(RepositoryPackage) run;
+}

script/tool/test/analyze_command_test.dart

@@ -442,6 +442,153 @@ void main() {
       });
     });
 
+    group('dart_code_linter', () {
+      test('runs dart_code_linter if present in dev_dependencies', () async {
+        final RepositoryPackage package = createFakePackage('a_package', packagesDir, isFlutter: true);
+        _writeFakePubspecWithLinter(package, inDevDependencies: true);
+
+        _mockStandardFlutterAndDartProcesses(processRunner, extraFlutterCalls: [
+          FakeProcessInfo(
+            MockProcess(),
+            <String>['pub', 'run', 'dart_code_linter:metrics'],
+          ),
+        ]);
+
+        final List<String> output = await runCapturingPrint(runner, <String>['analyze']);
+
+        expect(
+          processRunner.recordedCalls,
+          orderedEquals(<ProcessCall>[
+            ProcessCall('flutter', const <String>['pub', 'get'], package.path),
+            ProcessCall('dart', const <String>['analyze', '--fatal-infos'], package.path),
+            ProcessCall(
+              'flutter',
+              const <String>[
+                'pub',
+                'run',
+                'dart_code_linter:metrics',
+                'analyze',
+                'lib',
+                '--set-exit-on-violation-level=warning',
+              ],
+              package.path,
+            ),
+          ]),
+        );
+        expect(output, contains('Running dart_code_linter:metrics analysis...'));
+      });
+
+      test('does not run dart_code_linter if present in dependencies', () async {
+        final RepositoryPackage package = createFakePackage('a_package', packagesDir, isFlutter: true);
+        _writeFakePubspecWithLinter(package, inDependencies: true);
+
+        _mockStandardFlutterAndDartProcesses(processRunner);
+
+        final List<String> output = await runCapturingPrint(runner, <String>['analyze']);
+
+        expect(
+          processRunner.recordedCalls,
+          orderedEquals(<ProcessCall>[
+            ProcessCall('flutter', const <String>['pub', 'get'], package.path),
+            ProcessCall('dart', const <String>['analyze', '--fatal-infos'], package.path),
+          ]),
+        );
+        final String combinedOutput = output.join('\n').toLowerCase();
+        expect(combinedOutput, isNot(contains('dart_code_linter')));
+        expect(combinedOutput, isNot(contains('metrics')));
+      });
+
+      test('does not run dart_code_linter if not present', () async {
+        final RepositoryPackage package = createFakePackage('a_package', packagesDir, isFlutter: true);
+
+        _mockStandardFlutterAndDartProcesses(processRunner);
+
+        final List<String> output = await runCapturingPrint(runner, <String>['analyze']);
+
+        expect(
+          processRunner.recordedCalls,
+          orderedEquals(<ProcessCall>[
+            ProcessCall('flutter', const <String>['pub', 'get'], package.path),
+            ProcessCall('dart', const <String>['analyze', '--fatal-infos'], package.path),
+          ]),
+        );
+        final String combinedOutput = output.join('\n').toLowerCase();
+        expect(combinedOutput, isNot(contains('dart_code_linter')));
+        expect(combinedOutput, isNot(contains('metrics')));
+      });
+
+      test('runs dart_code_linter using dart for pure Dart packages', () async {
+        final RepositoryPackage package = createFakePackage('a_package', packagesDir, isFlutter: false);
+        _writeFakePubspecWithLinter(package, inDevDependencies: true, includeFlutter: false);
+
+        processRunner.mockProcessesForExecutable['dart'] = <FakeProcessInfo>[
+          FakeProcessInfo(
+            MockProcess(),
+            <String>['pub', 'get'],
+          ),
+          FakeProcessInfo(
+            MockProcess(),
+            <String>['analyze'],
+          ),
+          FakeProcessInfo(
+            MockProcess(),
+            <String>['run', 'dart_code_linter:metrics'],
+          ),
+        ];
+
+        final List<String> output = await runCapturingPrint(runner, <String>['analyze']);
+
+        expect(
+          processRunner.recordedCalls,
+          orderedEquals(<ProcessCall>[
+            ProcessCall('dart', const <String>['pub', 'get'], package.path),
+            ProcessCall('dart', const <String>['analyze', '--fatal-infos'], package.path),
+            ProcessCall(
+              'dart',
+              const <String>[
+                'run',
+                'dart_code_linter:metrics',
+                'analyze',
+                'lib',
+                '--set-exit-on-violation-level=warning',
+              ],
+              package.path,
+            ),
+          ]),
+        );
+        expect(output, contains('Running dart_code_linter:metrics analysis...'));
+      });
+
+      test('fails if dart_code_linter analysis fails', () async {
+        final RepositoryPackage package = createFakePackage('a_package', packagesDir, isFlutter: true);
+        _writeFakePubspecWithLinter(package, inDevDependencies: true);
+
+        _mockStandardFlutterAndDartProcesses(processRunner, extraFlutterCalls: [
+          FakeProcessInfo(
+            MockProcess(exitCode: 1),
+            <String>['pub', 'run', 'dart_code_linter:metrics'],
+          ),
+        ]);
+
+        Error? commandError;
+        final List<String> output = await runCapturingPrint(
+          runner,
+          <String>['analyze'],
+          errorHandler: (Error e) {
+            commandError = e;
+          },
+        );
+
+        expect(commandError, isA<ToolExit>());
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Metrics violations found. See the package\'s local "analysis_options.yaml" for configured thresholds.'),
+          ]),
+        );
+      });
+    });
+
     test('skips if requested if "pub get" fails in the resolver', () async {
       final RepositoryPackage plugin = createFakePlugin('foo', packagesDir);
 
@@ -1526,3 +1673,41 @@ packages/package_a/lib/foo.dart
     });
   });
 }
+
+void _writeFakePubspecWithLinter(
+  RepositoryPackage package, {
+  bool inDevDependencies = false,
+  bool inDependencies = false,
+  bool includeFlutter = true,
+}) {
+  package.pubspecFile.writeAsStringSync('''
+name: ${package.directory.basename}
+version: 0.0.1
+environment:
+  sdk: ">=2.14.0 <4.0.0"
+  ${includeFlutter ? 'flutter: ">=2.5.0"' : ''}
+dependencies:
+  ${includeFlutter ? 'flutter:\n    sdk: flutter' : ''}
+${inDependencies ? '  dart_code_linter: 4.1.5' : ''}
+${inDevDependencies ? 'dev_dependencies:\n  dart_code_linter: 4.1.5' : ''}
+''');
+}
+
+void _mockStandardFlutterAndDartProcesses(
+  RecordingProcessRunner processRunner, {
+  List<FakeProcessInfo> extraFlutterCalls = const <FakeProcessInfo>[],
+}) {
+  processRunner.mockProcessesForExecutable['flutter'] = <FakeProcessInfo>[
+    FakeProcessInfo(
+      MockProcess(),
+      const <String>['pub', 'get'],
+    ),
+    ...extraFlutterCalls,
+  ];
+  processRunner.mockProcessesForExecutable['dart'] = <FakeProcessInfo>[
+    FakeProcessInfo(
+      MockProcess(),
+      const <String>['analyze'],
+    ),
+  ];
+}