Check license header in flutter analyze

.github/workflows/amplify_lints.yaml

@@ -7,6 +7,7 @@ on:
       - stable
     paths:
       - '.github/workflows/amplify_lints.yaml'
+      - '.github/workflows/dart_native.yaml'
       - '.github/workflows/dart_vm.yaml'
       - 'packages/amplify_lints/**/*.dart'
       - 'packages/amplify_lints/**/*.yaml'
@@ -15,6 +16,7 @@ on:
   pull_request:
     paths:
       - '.github/workflows/amplify_lints.yaml'
+      - '.github/workflows/dart_native.yaml'
       - '.github/workflows/dart_vm.yaml'
       - 'packages/amplify_lints/**/*.dart'
       - 'packages/amplify_lints/**/*.yaml'
@@ -45,3 +47,10 @@ jobs:
     with:
       package-name: amplify_lints
       working-directory: packages/amplify_lints
+  native_test:
+    needs: test
+    uses: ./.github/workflows/dart_native.yaml
+    secrets: inherit 
+    with:
+      package-name: amplify_lints
+      working-directory: packages/amplify_lints

packages/amplify_lints/lib/amplify_lints.dart

@@ -0,0 +1,23 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+/// Custom lint rules for Amplify Flutter packages.
+///
+/// This package provides custom lint rules using `custom_lint` that are
+/// automatically discovered by the Dart Analysis Server when `custom_lint`
+/// is enabled in `analysis_options.yaml` and this package is a dependency.
+library amplify_lints;
+
+import 'package:custom_lint_builder/custom_lint_builder.dart';
+
+import 'src/lints/missing_license_header.dart';
+
+/// Creates the plugin instance for custom_lint to discover.
+PluginBase createPlugin() => _AmplifyLintsPlugin();
+
+class _AmplifyLintsPlugin extends PluginBase {
+  @override
+  List<LintRule> getLintRules(CustomLintConfigs configs) => [
+    MissingLicenseHeader(),
+  ];
+}

packages/amplify_lints/lib/app.yaml

@@ -1,5 +1,8 @@
 include: package:flutter_lints/flutter.yaml
 
+plugins:
+  amplify_lints: any
+
 analyzer:
   language:
     strict-casts: true
@@ -14,7 +17,7 @@ linter:
     - avoid_field_initializers_in_const_classes        # To prefer using getters over fields.
     - cancel_subscriptions                             # To avoid memory leaks and to prevent code from firing after a subscription is no longer being used.
     - close_sinks                                      # To avoid memory leaks.
-    - directives_ordering                              # To maintain visual separation of a file’s imports.
+    - directives_ordering                              # To maintain visual separation of a file's imports.
     - eol_at_end_of_file                               # To provide consistency across our repos/languages.
     - flutter_style_todos                              # To ensure traceability of TODOs.
     - invalid_case_patterns                            # To prevent invalid case statements.

packages/amplify_lints/lib/library.yaml

@@ -1,5 +1,8 @@
 include: package:lints/recommended.yaml
 
+plugins:
+  amplify_lints: any
+
 analyzer:
   language:
     strict-casts: true
@@ -31,7 +34,7 @@ linter:
     - conditional_uri_does_not_exist                   # To prevent accidentally referencing a nonexistent file.
     - depend_on_referenced_packages                    # To prevent issues publishing.
     - deprecated_consistency                           # To encourage correct usage of deprecation and provide a better DX.
-    - directives_ordering                              # To maintain visual separation of a file’s imports.
+    - directives_ordering                              # To maintain visual separation of a file's imports.
     - eol_at_end_of_file                               # To provide consistency across our repos/languages.
     - flutter_style_todos                              # To ensure traceability of TODOs.
     - invalid_case_patterns                            # To prevent invalid case statements.

packages/amplify_lints/lib/main.dart

@@ -0,0 +1,15 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+/// Entry point for the amplify_lints analyzer plugin.
+///
+/// This file is automatically discovered by the Dart Analysis Server
+/// when amplify_lints is enabled as a plugin in `analysis_options.yaml`.
+library;
+
+import 'package:amplify_lints/src/plugin.dart';
+
+export 'src/plugin.dart';
+
+/// The top-level plugin instance required by the Dart Analysis Server.
+final plugin = AmplifyLintsPlugin();

packages/amplify_lints/lib/src/fixes/add_license_header_fix.dart

@@ -0,0 +1,35 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'package:amplify_lints/src/lints/missing_license_header.dart';
+import 'package:analysis_server_plugin/edit/dart/correction_producer.dart';
+import 'package:analysis_server_plugin/edit/dart/dart_fix_kind_priority.dart';
+import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
+import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
+
+/// A quick fix that adds the Amazon/Apache-2.0 license header to the top
+/// of a Dart file.
+class AddLicenseHeaderFix extends ResolvedCorrectionProducer {
+  /// Creates a new [AddLicenseHeaderFix].
+  AddLicenseHeaderFix({required super.context});
+
+  static const _fixKind = FixKind(
+    'amplify_lints.fix.addLicenseHeader',
+    DartFixKindPriority.standard,
+    'Add license header',
+  );
+
+  @override
+  CorrectionApplicability get applicability =>
+      CorrectionApplicability.acrossSingleFile;
+
+  @override
+  FixKind get fixKind => _fixKind;
+
+  @override
+  Future<void> compute(ChangeBuilder builder) async {
+    await builder.addDartFileEdit(file, (builder) {
+      builder.addSimpleInsertion(0, '${licenseHeader.join('\n')}\n\n');
+    });
+  }
+}

packages/amplify_lints/lib/src/lints/missing_license_header.dart

@@ -0,0 +1,92 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'package:analyzer/analysis_rule/analysis_rule.dart';
+import 'package:analyzer/analysis_rule/rule_context.dart';
+import 'package:analyzer/analysis_rule/rule_visitor_registry.dart';
+import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/visitor.dart';
+import 'package:analyzer/error/error.dart';
+
+/// The expected license header lines.
+const licenseHeader = [
+  '// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.',
+  '// SPDX-License-Identifier: Apache-2.0',
+];
+
+/// A custom lint rule that checks for the presence of the standard
+/// Amazon/Apache-2.0 license header at the top of every Dart file.
+///
+/// **Good:**
+/// ```dart
+/// // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+/// // SPDX-License-Identifier: Apache-2.0
+///
+/// library my_library;
+/// ```
+///
+/// **Bad:**
+/// ```dart
+/// library my_library;
+/// ```
+class MissingLicenseHeader extends AnalysisRule {
+  /// Creates a new [MissingLicenseHeader] lint rule.
+  MissingLicenseHeader()
+    : super(
+        name: 'missing_license_header',
+        description:
+            'Dart files must start with the Amazon copyright and '
+            'Apache-2.0 license header.',
+      );
+
+  /// The lint code reported by this rule.
+  static const LintCode code = LintCode(
+    'missing_license_header',
+    'Dart files must start with the Amazon copyright and Apache-2.0 '
+        'license header.',
+    correctionMessage: 'Add the license header to the top of this file.',
+  );
+
+  @override
+  LintCode get diagnosticCode => code;
+
+  @override
+  void registerNodeProcessors(
+    RuleVisitorRegistry registry,
+    RuleContext context,
+  ) {
+    final visitor = _Visitor(this, context);
+    registry.addCompilationUnit(this, visitor);
+  }
+}
+
+class _Visitor extends SimpleAstVisitor<void> {
+  _Visitor(this.rule, this.context);
+
+  final AnalysisRule rule;
+  final RuleContext context;
+
+  @override
+  void visitCompilationUnit(CompilationUnit node) {
+    final unit = context.currentUnit;
+    if (unit == null) return;
+
+    // Use the content provided by the analysis context (no need to read
+    // the file from disk).
+    if (_hasLicenseHeader(unit.content)) return;
+
+    // Report the lint on the first token in the file.
+    rule.reportAtToken(node.beginToken);
+  }
+}
+
+/// Returns `true` if [content] starts with the expected license header.
+bool _hasLicenseHeader(String content) {
+  final lines = content.split('\n');
+  if (lines.length < licenseHeader.length) return false;
+
+  for (var i = 0; i < licenseHeader.length; i++) {
+    if (lines[i].trimRight() != licenseHeader[i]) return false;
+  }
+  return true;
+}

packages/amplify_lints/lib/src/plugin.dart

@@ -0,0 +1,28 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'package:amplify_lints/src/fixes/add_license_header_fix.dart';
+import 'package:amplify_lints/src/lints/missing_license_header.dart';
+import 'package:analysis_server_plugin/plugin.dart';
+import 'package:analysis_server_plugin/registry.dart';
+
+/// The amplify_lints analyzer plugin.
+///
+/// Registers custom lint rules and quick fixes for Amplify Flutter packages.
+class AmplifyLintsPlugin extends Plugin {
+  @override
+  String get name => 'amplify_lints';
+
+  @override
+  void register(PluginRegistry registry) {
+    // Register lint rules (disabled by default, must be enabled in
+    // analysis_options.yaml).
+    registry.registerWarningRule(MissingLicenseHeader());
+
+    // Register quick fixes associated with lint rules.
+    registry.registerFixForRule(
+      MissingLicenseHeader.code,
+      AddLicenseHeaderFix.new,
+    );
+  }
+}

packages/amplify_lints/pubspec.yaml

@@ -9,5 +9,13 @@ environment:
   sdk: ^3.9.0
 
 dependencies:
+  analysis_server_plugin: any
+  analyzer: any
+  analyzer_plugin: any
   flutter_lints: ^6.0.0
   lints: ^6.0.0
+
+dev_dependencies:
+  analyzer_testing: ^0.1.0
+  test: ^1.24.0
+  test_reflective_loader: ^0.2.0

packages/amplify_lints/test/lints/missing_license_header_test.dart

@@ -0,0 +1,109 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'dart:io';
+
+import 'package:test/test.dart';
+
+/// The expected license header lines (mirrored from the lint rule).
+const _licenseHeader = [
+  '// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.',
+  '// SPDX-License-Identifier: Apache-2.0',
+];
+
+/// Returns `true` if [content] starts with the expected license header.
+///
+/// This mirrors the private `_hasLicenseHeader` function from the lint rule
+/// for unit testing purposes.
+bool _hasLicenseHeader(String content) {
+  final lines = content.split('\n');
+  if (lines.length < _licenseHeader.length) return false;
+
+  for (var i = 0; i < _licenseHeader.length; i++) {
+    if (lines[i].trimRight() != _licenseHeader[i]) return false;
+  }
+  return true;
+}
+
+void main() {
+  late Directory tmpDir;
+
+  setUp(() {
+    tmpDir = Directory.systemTemp.createTempSync('license_header_test_');
+  });
+
+  tearDown(() {
+    tmpDir.deleteSync(recursive: true);
+  });
+
+  group('MissingLicenseHeader logic', () {
+    test('detects missing license header', () {
+      const content = 'void main() {}\n';
+      expect(_hasLicenseHeader(content), isFalse);
+    });
+
+    test('detects present license header', () {
+      const content =
+          '// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.\n'
+          '// SPDX-License-Identifier: Apache-2.0\n'
+          '\n'
+          'void main() {}\n';
+      expect(_hasLicenseHeader(content), isTrue);
+    });
+
+    test('detects missing SPDX line (only copyright present)', () {
+      const content =
+          '// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.\n'
+          '\n'
+          'void main() {}\n';
+      expect(_hasLicenseHeader(content), isFalse);
+    });
+
+    test('detects missing copyright line (only SPDX present)', () {
+      const content =
+          '// SPDX-License-Identifier: Apache-2.0\n'
+          '\n'
+          'void main() {}\n';
+      expect(_hasLicenseHeader(content), isFalse);
+    });
+
+    test('detects wrong order of header lines', () {
+      const content =
+          '// SPDX-License-Identifier: Apache-2.0\n'
+          '// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.\n'
+          '\n'
+          'void main() {}\n';
+      expect(_hasLicenseHeader(content), isFalse);
+    });
+
+    test('allows content after the header', () {
+      const content =
+          '// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.\n'
+          '// SPDX-License-Identifier: Apache-2.0\n'
+          '\n'
+          "import 'dart:core';\n"
+          '\n'
+          'class Foo {\n'
+          '  void bar() {}\n'
+          '}\n';
+      expect(_hasLicenseHeader(content), isTrue);
+    });
+
+    test('allows header with trailing whitespace', () {
+      const content =
+          '// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.  \n'
+          '// SPDX-License-Identifier: Apache-2.0  \n'
+          '\n'
+          'void main() {}\n';
+      expect(_hasLicenseHeader(content), isTrue);
+    });
+
+    test('rejects empty file', () {
+      expect(_hasLicenseHeader(''), isFalse);
+    });
+
+    test('rejects single line file', () {
+      expect(_hasLicenseHeader('void main() {}'), isFalse);
+    });
+  });
+}