dev/snippets/test/snippets_test.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:convert';

 import 'package:file/file.dart';
 import 'package:file/memory.dart';
 import 'package:path/path.dart' as path;
 import 'package:platform/platform.dart';
 import 'package:pub_semver/pub_semver.dart';
 import 'package:snippets/snippets.dart';
 import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;

 import '../bin/snippets.dart' as snippets_main;
 import 'fake_process_manager.dart';

 class FakeFlutterInformation extends FlutterInformation {
   FakeFlutterInformation(this.flutterRoot);

   final Directory flutterRoot;

   @override
   Directory getFlutterRoot() {
     return flutterRoot;
   }

   @override
   Map<String, dynamic> getFlutterInformation() {
     return <String, dynamic>{
       'flutterRoot': flutterRoot,
       'frameworkVersion': Version(2, 10, 0),
       'dartSdkVersion': Version(2, 12, 1),
     };
   }
 }

 void main() {
   group('Generator', () {
     late MemoryFileSystem memoryFileSystem = MemoryFileSystem();
     late FlutterRepoSnippetConfiguration configuration;
     late SnippetGenerator generator;
     late Directory tmpDir;

     void writeSkeleton(String type) {
       switch (type) {
         case 'dartpad':
           configuration.getHtmlSkeletonFile('dartpad').writeAsStringSync('''
 <div>HTML Bits (DartPad-style)</div>
 <iframe class="snippet-dartpad" src="https://dartpad.dev/embed-flutter.html?split=60&run=true&sample_id={{id}}&sample_channel={{channel}}"></iframe>
 <div>More HTML Bits</div>
 ''');
         case 'sample':
         case 'snippet':
           configuration.getHtmlSkeletonFile(type).writeAsStringSync('''
 <div>HTML Bits</div>
 {{description}}
 <pre>{{code}}</pre>
 <pre>{{app}}</pre>
 <div>More HTML Bits</div>
 ''');
       }
     }

     setUp(() {
       // Create a new filesystem.
       memoryFileSystem = MemoryFileSystem();
       tmpDir = memoryFileSystem.systemTempDirectory
           .createTempSync('flutter_snippets_test.');
       configuration = FlutterRepoSnippetConfiguration(
           flutterRoot: memoryFileSystem
               .directory(path.join(tmpDir.absolute.path, 'flutter')),
           filesystem: memoryFileSystem);
       configuration.skeletonsDirectory.createSync(recursive: true);
       <String>['dartpad', 'sample', 'snippet'].forEach(writeSkeleton);
       FlutterInformation.instance =
           FakeFlutterInformation(configuration.flutterRoot);
       generator = SnippetGenerator(
           configuration: configuration,
           filesystem: memoryFileSystem,
           flutterRoot: configuration.skeletonsDirectory.parent);
     });

     test('generates samples', () async {
       final File inputFile = memoryFileSystem
           .file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
         ..createSync(recursive: true)
         ..writeAsStringSync(r'''
 A description of the sample.

 On several lines.

 ** See code in examples/api/widgets/foo/foo_example.0.dart **
 ''');
       final String examplePath = path.join(configuration.flutterRoot.path, 'examples/api/widgets/foo/foo_example.0.dart');
       memoryFileSystem.file(examplePath)
         ..create(recursive: true)
         ..writeAsStringSync('''
 // Copyright

 // Flutter code sample for [MyElement].

 void main() {
   runApp(MaterialApp(title: 'foo'));
 }\n'''
         );
       final File outputFile = memoryFileSystem
           .file(path.join(tmpDir.absolute.path, 'snippet_out.txt'));
       final SnippetDartdocParser sampleParser =
           SnippetDartdocParser(memoryFileSystem);
       const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
       const int sourceLine = 222;
       final SourceElement element = sampleParser.parseFromDartdocToolFile(
         inputFile,
         element: 'MyElement',
         startLine: sourceLine,
         sourceFile: memoryFileSystem.file(sourcePath),
         type: 'sample',
       );

       expect(element.samples, isNotEmpty);
       element.samples.first.metadata.addAll(<String, Object?>{
         'channel': 'stable',
       });
       final String code = generator.generateCode(
         element.samples.first,
         output: outputFile,
       );
       expect(code, contains("runApp(MaterialApp(title: 'foo'));"));
       final String html = generator.generateHtml(
         element.samples.first,
       );
       expect(html, contains('<div>HTML Bits</div>'));
       expect(html, contains('<div>More HTML Bits</div>'));
       expect(html, contains(r'''runApp(MaterialApp(title: &#39;foo&#39;));'''));
       expect(html, isNot(contains('sample_channel=stable')));
       expect(
           html,
           contains('A description of the sample.\n'
               '\n'
               'On several lines.{@inject-html}</div>'));
       expect(html, contains('void main() {'));

       final String outputContents = outputFile.readAsStringSync();
       expect(outputContents, contains('void main() {'));
     });

     test('generates snippets', () async {
       final File inputFile = memoryFileSystem
           .file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
         ..createSync(recursive: true)
         ..writeAsStringSync(r'''
 A description of the snippet.

 On several lines.

 ```code
 void main() {
   print('The actual $name.');
 }
 ```
 ''');

       final SnippetDartdocParser sampleParser =
           SnippetDartdocParser(memoryFileSystem);
       const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
       const int sourceLine = 222;
       final SourceElement element = sampleParser.parseFromDartdocToolFile(
         inputFile,
         element: 'MyElement',
         startLine: sourceLine,
         sourceFile: memoryFileSystem.file(sourcePath),
         type: 'snippet',
       );
       expect(element.samples, isNotEmpty);
       element.samples.first.metadata.addAll(<String, Object>{
         'channel': 'stable',
       });
       final String code = generator.generateCode(element.samples.first);
       expect(code, contains('// A description of the snippet.'));
       final String html = generator.generateHtml(element.samples.first);
       expect(html, contains('<div>HTML Bits</div>'));
       expect(html, contains('<div>More HTML Bits</div>'));
       expect(html, contains(r'  print(&#39;The actual $name.&#39;);'));
       expect(
           html,
           contains(
               '<div class="snippet-description">{@end-inject-html}A description of the snippet.\n\n'
               'On several lines.{@inject-html}</div>\n'));
       expect(html, contains('main() {'));
     });

     test('generates dartpad samples', () async {
       final File inputFile = memoryFileSystem
           .file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
         ..createSync(recursive: true)
         ..writeAsStringSync(r'''
 A description of the snippet.

 On several lines.

 ** See code in examples/api/widgets/foo/foo_example.0.dart **
 ''');
       final String examplePath = path.join(configuration.flutterRoot.path, 'examples/api/widgets/foo/foo_example.0.dart');
       memoryFileSystem.file(examplePath)
         ..create(recursive: true)
         ..writeAsStringSync('''
 // Copyright

 // Flutter code sample for [MyElement].

 void main() {
   runApp(MaterialApp(title: 'foo'));
 }\n'''
         );

       final SnippetDartdocParser sampleParser =
           SnippetDartdocParser(memoryFileSystem);
       const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
       const int sourceLine = 222;
       final SourceElement element = sampleParser.parseFromDartdocToolFile(
         inputFile,
         element: 'MyElement',
         startLine: sourceLine,
         sourceFile: memoryFileSystem.file(sourcePath),
         type: 'dartpad',
       );
       expect(element.samples, isNotEmpty);
       element.samples.first.metadata.addAll(<String, Object>{
         'channel': 'stable',
       });
       final String code = generator.generateCode(element.samples.first);
       expect(code, contains("runApp(MaterialApp(title: 'foo'));"));
       final String html = generator.generateHtml(element.samples.first);
       expect(html, contains('<div>HTML Bits (DartPad-style)</div>'));
       expect(html, contains('<div>More HTML Bits</div>'));
       expect(
           html,
           contains(
               '<iframe class="snippet-dartpad" src="https://dartpad.dev/embed-flutter.html?split=60&run=true&sample_id=MyElement.0&sample_channel=stable"></iframe>\n'));
     });

     test('generates sample metadata', () async {
       final File inputFile = memoryFileSystem
           .file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
         ..createSync(recursive: true)
         ..writeAsStringSync(r'''
 A description of the snippet.

 On several lines.

 ```dart
 void main() {
   print('The actual $name.');
 }
 ```
 ''');

       final File outputFile = memoryFileSystem
           .file(path.join(tmpDir.absolute.path, 'snippet_out.dart'));
       final File expectedMetadataFile = memoryFileSystem
           .file(path.join(tmpDir.absolute.path, 'snippet_out.json'));

       final SnippetDartdocParser sampleParser =
           SnippetDartdocParser(memoryFileSystem);
       const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
       const int sourceLine = 222;
       final SourceElement element = sampleParser.parseFromDartdocToolFile(
         inputFile,
         element: 'MyElement',
         startLine: sourceLine,
         sourceFile: memoryFileSystem.file(sourcePath),
         type: 'sample',
       );
       expect(element.samples, isNotEmpty);
       element.samples.first.metadata
           .addAll(<String, Object>{'channel': 'stable'});
       generator.generateCode(element.samples.first, output: outputFile);
       expect(expectedMetadataFile.existsSync(), isTrue);
       final Map<String, dynamic> json =
           jsonDecode(expectedMetadataFile.readAsStringSync())
               as Map<String, dynamic>;
       expect(json['id'], equals('MyElement.0'));
       expect(json['channel'], equals('stable'));
       expect(json['file'], equals('snippet_out.dart'));
       expect(json['description'],
           equals('A description of the snippet.\n\nOn several lines.'));
       expect(json['sourcePath'],
           equals('packages/flutter/lib/src/widgets/foo.dart'));
     });
   });

   group('snippets command line argument test', () {
     late MemoryFileSystem memoryFileSystem = MemoryFileSystem();
     late Directory tmpDir;
     late Directory flutterRoot;
     late FakeProcessManager fakeProcessManager;

     setUp(() {
       fakeProcessManager = FakeProcessManager();
       memoryFileSystem = MemoryFileSystem();
       tmpDir = memoryFileSystem.systemTempDirectory
           .createTempSync('flutter_snippets_test.');
       flutterRoot = memoryFileSystem
           .directory(path.join(tmpDir.absolute.path, 'flutter'))
         ..createSync(recursive: true);
     });

     test('command line arguments are parsed and passed to generator', () {
       final FakePlatform platform = FakePlatform(environment: <String, String>{
         'PACKAGE_NAME': 'dart:ui',
         'LIBRARY_NAME': 'library',
         'ELEMENT_NAME': 'element',
         'FLUTTER_ROOT': flutterRoot.absolute.path,
         // The details here don't really matter other than the flutter root.
         'FLUTTER_VERSION': '''
       {
         "frameworkVersion": "2.5.0-6.0.pre.55",
         "channel": "use_snippets_pkg",
         "repositoryUrl": "git@github.com:flutter/flutter.git",
         "frameworkRevision": "fec4641e1c88923ecd6c969e2ff8a0dd12dc0875",
         "frameworkCommitDate": "2021-08-11 15:19:48 -0700",
         "engineRevision": "d8bbebed60a77b3d4fe9c840dc94dfbce159d951",
         "dartSdkVersion": "2.14.0 (build 2.14.0-393.0.dev)",
         "flutterRoot": "${flutterRoot.absolute.path}"
       }''',
       });
       final FlutterInformation flutterInformation = FlutterInformation(
         filesystem: memoryFileSystem,
         processManager: fakeProcessManager,
         platform: platform,
       );
       FlutterInformation.instance = flutterInformation;
       MockSnippetGenerator mockSnippetGenerator = MockSnippetGenerator();
       snippets_main.snippetGenerator = mockSnippetGenerator;
       String errorMessage = '';
       errorExit = (String message) {
         errorMessage = message;
       };

       snippets_main.platform = platform;
       snippets_main.filesystem = memoryFileSystem;
       snippets_main.processManager = fakeProcessManager;
       final File input = memoryFileSystem
           .file(tmpDir.childFile('input.snippet'))
         ..writeAsString('/// Test file');
       snippets_main.main(
           <String>['--input=${input.absolute.path}']);

       final Map<String, dynamic> metadata =
           mockSnippetGenerator.sample.metadata;
       // Ignore the channel, because channel is really just the branch, and will be
       // different on development workstations.
       metadata.remove('channel');
       expect(
           metadata,
           equals(<String, dynamic>{
             'id': 'dart_ui.library.element',
             'element': 'element',
             'sourcePath': 'unknown.dart',
             'sourceLine': 1,
             'serial': '',
             'package': 'dart:ui',
             'library': 'library',
           }));

       snippets_main.main(<String>[]);
       expect(
           errorMessage,
           equals(
               'The --input option must be specified, either on the command line, or in the INPUT environment variable.'));
       errorMessage = '';

       snippets_main
           .main(<String>['--input=${input.absolute.path}', '--type=snippet']);
       expect(errorMessage, equals(''));
       errorMessage = '';

       mockSnippetGenerator = MockSnippetGenerator();
       snippets_main.snippetGenerator = mockSnippetGenerator;
       snippets_main.main(<String>[
         '--input=${input.absolute.path}',
         '--type=snippet',
         '--no-format-output'
       ]);
       expect(mockSnippetGenerator.formatOutput, equals(false));
       errorMessage = '';

       input.deleteSync();
       snippets_main.main(
           <String>['--input=${input.absolute.path}']);
       expect(errorMessage,
           equals('The input file ${input.absolute.path} does not exist.'));
       errorMessage = '';
     });
   });
 }

 class MockSnippetGenerator extends SnippetGenerator {
   late CodeSample sample;
   File? output;
   String? copyright;
   String? description;
   late bool formatOutput;
   late bool addSectionMarkers;
   late bool includeAssumptions;

   @override
   String generateCode(
     CodeSample sample, {
     File? output,
     String? copyright,
     String? description,
     bool formatOutput = true,
     bool addSectionMarkers = false,
     bool includeAssumptions = false,
   }) {
     this.sample = sample;
     this.output = output;
     this.copyright = copyright;
     this.description = description;
     this.formatOutput = formatOutput;
     this.addSectionMarkers = addSectionMarkers;
     this.includeAssumptions = includeAssumptions;

     return '';
   }

   @override
   String generateHtml(CodeSample sample) {
     return '';
   }
 }
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:convert';

	import 'package:file/file.dart';
	import 'package:file/memory.dart';
	import 'package:path/path.dart' as path;
	import 'package:platform/platform.dart';
	import 'package:pub_semver/pub_semver.dart';
	import 'package:snippets/snippets.dart';
	import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;

	import '../bin/snippets.dart' as snippets_main;
	import 'fake_process_manager.dart';

	class FakeFlutterInformation extends FlutterInformation {
	FakeFlutterInformation(this.flutterRoot);

	final Directory flutterRoot;

	@override
	Directory getFlutterRoot() {
	return flutterRoot;
	}

	@override
	Map<String, dynamic> getFlutterInformation() {
	return <String, dynamic>{
	'flutterRoot': flutterRoot,
	'frameworkVersion': Version(2, 10, 0),
	'dartSdkVersion': Version(2, 12, 1),
	};
	}
	}

	void main() {
	group('Generator', () {
	late MemoryFileSystem memoryFileSystem = MemoryFileSystem();
	late FlutterRepoSnippetConfiguration configuration;
	late SnippetGenerator generator;
	late Directory tmpDir;

	void writeSkeleton(String type) {
	switch (type) {
	case 'dartpad':
	configuration.getHtmlSkeletonFile('dartpad').writeAsStringSync('''
	<div>HTML Bits (DartPad-style)</div>
	<iframe class="snippet-dartpad" src="https://dartpad.dev/embed-flutter.html?split=60&run=true&sample_id={{id}}&sample_channel={{channel}}"></iframe>
	<div>More HTML Bits</div>
	''');
	case 'sample':
	case 'snippet':
	configuration.getHtmlSkeletonFile(type).writeAsStringSync('''
	<div>HTML Bits</div>
	{{description}}
	<pre>{{code}}</pre>
	<pre>{{app}}</pre>
	<div>More HTML Bits</div>
	''');
	}
	}

	setUp(() {
	// Create a new filesystem.
	memoryFileSystem = MemoryFileSystem();
	tmpDir = memoryFileSystem.systemTempDirectory
	.createTempSync('flutter_snippets_test.');
	configuration = FlutterRepoSnippetConfiguration(
	flutterRoot: memoryFileSystem
	.directory(path.join(tmpDir.absolute.path, 'flutter')),
	filesystem: memoryFileSystem);
	configuration.skeletonsDirectory.createSync(recursive: true);
	<String>['dartpad', 'sample', 'snippet'].forEach(writeSkeleton);
	FlutterInformation.instance =
	FakeFlutterInformation(configuration.flutterRoot);
	generator = SnippetGenerator(
	configuration: configuration,
	filesystem: memoryFileSystem,
	flutterRoot: configuration.skeletonsDirectory.parent);
	});

	test('generates samples', () async {
	final File inputFile = memoryFileSystem
	.file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
	..createSync(recursive: true)
	..writeAsStringSync(r'''
	A description of the sample.

	On several lines.

	See code in examples/api/widgets/foo/foo_example.0.dart
	''');
	final String examplePath = path.join(configuration.flutterRoot.path, 'examples/api/widgets/foo/foo_example.0.dart');
	memoryFileSystem.file(examplePath)
	..create(recursive: true)
	..writeAsStringSync('''
	// Copyright

	// Flutter code sample for [MyElement].

	void main() {
	runApp(MaterialApp(title: 'foo'));
	}\n'''
	);
	final File outputFile = memoryFileSystem
	.file(path.join(tmpDir.absolute.path, 'snippet_out.txt'));
	final SnippetDartdocParser sampleParser =
	SnippetDartdocParser(memoryFileSystem);
	const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
	const int sourceLine = 222;
	final SourceElement element = sampleParser.parseFromDartdocToolFile(
	inputFile,
	element: 'MyElement',
	startLine: sourceLine,
	sourceFile: memoryFileSystem.file(sourcePath),
	type: 'sample',
	);

	expect(element.samples, isNotEmpty);
	element.samples.first.metadata.addAll(<String, Object?>{
	'channel': 'stable',
	});
	final String code = generator.generateCode(
	element.samples.first,
	output: outputFile,
	);
	expect(code, contains("runApp(MaterialApp(title: 'foo'));"));
	final String html = generator.generateHtml(
	element.samples.first,
	);
	expect(html, contains('<div>HTML Bits</div>'));
	expect(html, contains('<div>More HTML Bits</div>'));
	expect(html, contains(r'''runApp(MaterialApp(title: 'foo'));'''));
	expect(html, isNot(contains('sample_channel=stable')));
	expect(
	html,
	contains('A description of the sample.\n'
	'\n'
	'On several lines.{@inject-html}</div>'));
	expect(html, contains('void main() {'));

	final String outputContents = outputFile.readAsStringSync();
	expect(outputContents, contains('void main() {'));
	});

	test('generates snippets', () async {
	final File inputFile = memoryFileSystem
	.file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
	..createSync(recursive: true)
	..writeAsStringSync(r'''
	A description of the snippet.

	On several lines.

	```code
	void main() {
	print('The actual $name.');
	}
	```
	''');

	final SnippetDartdocParser sampleParser =
	SnippetDartdocParser(memoryFileSystem);
	const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
	const int sourceLine = 222;
	final SourceElement element = sampleParser.parseFromDartdocToolFile(
	inputFile,
	element: 'MyElement',
	startLine: sourceLine,
	sourceFile: memoryFileSystem.file(sourcePath),
	type: 'snippet',
	);
	expect(element.samples, isNotEmpty);
	element.samples.first.metadata.addAll(<String, Object>{
	'channel': 'stable',
	});
	final String code = generator.generateCode(element.samples.first);
	expect(code, contains('// A description of the snippet.'));
	final String html = generator.generateHtml(element.samples.first);
	expect(html, contains('<div>HTML Bits</div>'));
	expect(html, contains('<div>More HTML Bits</div>'));
	expect(html, contains(r' print('The actual $name.');'));
	expect(
	html,
	contains(
	'<div class="snippet-description">{@end-inject-html}A description of the snippet.\n\n'
	'On several lines.{@inject-html}</div>\n'));
	expect(html, contains('main() {'));
	});

	test('generates dartpad samples', () async {
	final File inputFile = memoryFileSystem
	.file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
	..createSync(recursive: true)
	..writeAsStringSync(r'''
	A description of the snippet.

	On several lines.

	See code in examples/api/widgets/foo/foo_example.0.dart
	''');
	final String examplePath = path.join(configuration.flutterRoot.path, 'examples/api/widgets/foo/foo_example.0.dart');
	memoryFileSystem.file(examplePath)
	..create(recursive: true)
	..writeAsStringSync('''
	// Copyright

	// Flutter code sample for [MyElement].

	void main() {
	runApp(MaterialApp(title: 'foo'));
	}\n'''
	);

	final SnippetDartdocParser sampleParser =
	SnippetDartdocParser(memoryFileSystem);
	const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
	const int sourceLine = 222;
	final SourceElement element = sampleParser.parseFromDartdocToolFile(
	inputFile,
	element: 'MyElement',
	startLine: sourceLine,
	sourceFile: memoryFileSystem.file(sourcePath),
	type: 'dartpad',
	);
	expect(element.samples, isNotEmpty);
	element.samples.first.metadata.addAll(<String, Object>{
	'channel': 'stable',
	});
	final String code = generator.generateCode(element.samples.first);
	expect(code, contains("runApp(MaterialApp(title: 'foo'));"));
	final String html = generator.generateHtml(element.samples.first);
	expect(html, contains('<div>HTML Bits (DartPad-style)</div>'));
	expect(html, contains('<div>More HTML Bits</div>'));
	expect(
	html,
	contains(
	'<iframe class="snippet-dartpad" src="https://dartpad.dev/embed-flutter.html?split=60&run=true&sample_id=MyElement.0&sample_channel=stable"></iframe>\n'));
	});

	test('generates sample metadata', () async {
	final File inputFile = memoryFileSystem
	.file(path.join(tmpDir.absolute.path, 'snippet_in.txt'))
	..createSync(recursive: true)
	..writeAsStringSync(r'''
	A description of the snippet.

	On several lines.

	```dart
	void main() {
	print('The actual $name.');
	}
	```
	''');

	final File outputFile = memoryFileSystem
	.file(path.join(tmpDir.absolute.path, 'snippet_out.dart'));
	final File expectedMetadataFile = memoryFileSystem
	.file(path.join(tmpDir.absolute.path, 'snippet_out.json'));

	final SnippetDartdocParser sampleParser =
	SnippetDartdocParser(memoryFileSystem);
	const String sourcePath = 'packages/flutter/lib/src/widgets/foo.dart';
	const int sourceLine = 222;
	final SourceElement element = sampleParser.parseFromDartdocToolFile(
	inputFile,
	element: 'MyElement',
	startLine: sourceLine,
	sourceFile: memoryFileSystem.file(sourcePath),
	type: 'sample',
	);
	expect(element.samples, isNotEmpty);
	element.samples.first.metadata
	.addAll(<String, Object>{'channel': 'stable'});
	generator.generateCode(element.samples.first, output: outputFile);
	expect(expectedMetadataFile.existsSync(), isTrue);
	final Map<String, dynamic> json =
	jsonDecode(expectedMetadataFile.readAsStringSync())
	as Map<String, dynamic>;
	expect(json['id'], equals('MyElement.0'));
	expect(json['channel'], equals('stable'));
	expect(json['file'], equals('snippet_out.dart'));
	expect(json['description'],
	equals('A description of the snippet.\n\nOn several lines.'));
	expect(json['sourcePath'],
	equals('packages/flutter/lib/src/widgets/foo.dart'));
	});
	});

	group('snippets command line argument test', () {
	late MemoryFileSystem memoryFileSystem = MemoryFileSystem();
	late Directory tmpDir;
	late Directory flutterRoot;
	late FakeProcessManager fakeProcessManager;

	setUp(() {
	fakeProcessManager = FakeProcessManager();
	memoryFileSystem = MemoryFileSystem();
	tmpDir = memoryFileSystem.systemTempDirectory
	.createTempSync('flutter_snippets_test.');
	flutterRoot = memoryFileSystem
	.directory(path.join(tmpDir.absolute.path, 'flutter'))
	..createSync(recursive: true);
	});

	test('command line arguments are parsed and passed to generator', () {
	final FakePlatform platform = FakePlatform(environment: <String, String>{
	'PACKAGE_NAME': 'dart:ui',
	'LIBRARY_NAME': 'library',
	'ELEMENT_NAME': 'element',
	'FLUTTER_ROOT': flutterRoot.absolute.path,
	// The details here don't really matter other than the flutter root.
	'FLUTTER_VERSION': '''
	{
	"frameworkVersion": "2.5.0-6.0.pre.55",
	"channel": "use_snippets_pkg",
	"repositoryUrl": "git@github.com:flutter/flutter.git",
	"frameworkRevision": "fec4641e1c88923ecd6c969e2ff8a0dd12dc0875",
	"frameworkCommitDate": "2021-08-11 15:19:48 -0700",
	"engineRevision": "d8bbebed60a77b3d4fe9c840dc94dfbce159d951",
	"dartSdkVersion": "2.14.0 (build 2.14.0-393.0.dev)",
	"flutterRoot": "${flutterRoot.absolute.path}"
	}''',
	});
	final FlutterInformation flutterInformation = FlutterInformation(
	filesystem: memoryFileSystem,
	processManager: fakeProcessManager,
	platform: platform,
	);
	FlutterInformation.instance = flutterInformation;
	MockSnippetGenerator mockSnippetGenerator = MockSnippetGenerator();
	snippets_main.snippetGenerator = mockSnippetGenerator;
	String errorMessage = '';
	errorExit = (String message) {
	errorMessage = message;
	};

	snippets_main.platform = platform;
	snippets_main.filesystem = memoryFileSystem;
	snippets_main.processManager = fakeProcessManager;
	final File input = memoryFileSystem
	.file(tmpDir.childFile('input.snippet'))
	..writeAsString('/// Test file');
	snippets_main.main(
	<String>['--input=${input.absolute.path}']);

	final Map<String, dynamic> metadata =
	mockSnippetGenerator.sample.metadata;
	// Ignore the channel, because channel is really just the branch, and will be
	// different on development workstations.
	metadata.remove('channel');
	expect(
	metadata,
	equals(<String, dynamic>{
	'id': 'dart_ui.library.element',
	'element': 'element',
	'sourcePath': 'unknown.dart',
	'sourceLine': 1,
	'serial': '',
	'package': 'dart:ui',
	'library': 'library',
	}));

	snippets_main.main(<String>[]);
	expect(
	errorMessage,
	equals(
	'The --input option must be specified, either on the command line, or in the INPUT environment variable.'));
	errorMessage = '';

	snippets_main
	.main(<String>['--input=${input.absolute.path}', '--type=snippet']);
	expect(errorMessage, equals(''));
	errorMessage = '';

	mockSnippetGenerator = MockSnippetGenerator();
	snippets_main.snippetGenerator = mockSnippetGenerator;
	snippets_main.main(<String>[
	'--input=${input.absolute.path}',
	'--type=snippet',
	'--no-format-output'
	]);
	expect(mockSnippetGenerator.formatOutput, equals(false));
	errorMessage = '';

	input.deleteSync();
	snippets_main.main(
	<String>['--input=${input.absolute.path}']);
	expect(errorMessage,
	equals('The input file ${input.absolute.path} does not exist.'));
	errorMessage = '';
	});
	});
	}

	class MockSnippetGenerator extends SnippetGenerator {
	late CodeSample sample;
	File? output;
	String? copyright;
	String? description;
	late bool formatOutput;
	late bool addSectionMarkers;
	late bool includeAssumptions;

	@override
	String generateCode(
	CodeSample sample, {
	File? output,
	String? copyright,
	String? description,
	bool formatOutput = true,
	bool addSectionMarkers = false,
	bool includeAssumptions = false,
	}) {
	this.sample = sample;
	this.output = output;
	this.copyright = copyright;
	this.description = description;
	this.formatOutput = formatOutput;
	this.addSectionMarkers = addSectionMarkers;
	this.includeAssumptions = includeAssumptions;

	return '';
	}

	@override
	String generateHtml(CodeSample sample) {
	return '';
	}
	}