packages/flutter_tools/lib/src/flutter_manifest.dart - mirrors/flutter - Git at Google

 // Copyright 2017 The Chromium 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 'package:meta/meta.dart';
 import 'package:pub_semver/pub_semver.dart';
 import 'package:yaml/yaml.dart';

 import 'base/file_system.dart';
 import 'base/user_messages.dart';
 import 'base/utils.dart';
 import 'cache.dart';
 import 'globals.dart';
 import 'plugins.dart';

 /// A wrapper around the `flutter` section in the `pubspec.yaml` file.
 class FlutterManifest {
   FlutterManifest._();

   /// Returns an empty manifest.
   static FlutterManifest empty() {
     final FlutterManifest manifest = FlutterManifest._();
     manifest._descriptor = const <String, dynamic>{};
     manifest._flutterDescriptor = const <String, dynamic>{};
     return manifest;
   }

   /// Returns null on invalid manifest. Returns empty manifest on missing file.
   static FlutterManifest createFromPath(String path) {
     if (path == null || !fs.isFileSync(path)) {
       return _createFromYaml(null);
     }
     final String manifest = fs.file(path).readAsStringSync();
     return createFromString(manifest);
   }

   /// Returns null on missing or invalid manifest
   @visibleForTesting
   static FlutterManifest createFromString(String manifest) {
     return _createFromYaml(loadYaml(manifest));
   }

   static FlutterManifest _createFromYaml(dynamic yamlDocument) {
     final FlutterManifest pubspec = FlutterManifest._();
     if (yamlDocument != null && !_validate(yamlDocument)) {
       return null;
     }

     final Map<dynamic, dynamic> yamlMap = yamlDocument;
     if (yamlMap != null) {
       pubspec._descriptor = yamlMap.cast<String, dynamic>();
     } else {
       pubspec._descriptor = <String, dynamic>{};
     }

     final Map<dynamic, dynamic> flutterMap = pubspec._descriptor['flutter'];
     if (flutterMap != null) {
       pubspec._flutterDescriptor = flutterMap.cast<String, dynamic>();
     } else {
       pubspec._flutterDescriptor = <String, dynamic>{};
     }

     return pubspec;
   }

   /// A map representation of the entire `pubspec.yaml` file.
   Map<String, dynamic> _descriptor;

   /// A map representation of the `flutter` section in the `pubspec.yaml` file.
   Map<String, dynamic> _flutterDescriptor;

   /// True if the `pubspec.yaml` file does not exist.
   bool get isEmpty => _descriptor.isEmpty;

   /// The string value of the top-level `name` property in the `pubspec.yaml` file.
   String get appName => _descriptor['name'] ?? '';

   // Flag to avoid printing multiple invalid version messages.
   bool _hasShowInvalidVersionMsg = false;

   /// The version String from the `pubspec.yaml` file.
   /// Can be null if it isn't set or has a wrong format.
   String get appVersion {
     final String verStr = _descriptor['version']?.toString();
     if (verStr == null) {
       return null;
     }

     Version version;
     try {
       version = Version.parse(verStr);
     } on Exception {
       if (!_hasShowInvalidVersionMsg) {
         printStatus(userMessages.invalidVersionSettingHintMessage(verStr), emphasis: true);
         _hasShowInvalidVersionMsg = true;
       }
     }
     return version?.toString();
   }

   /// The build version name from the `pubspec.yaml` file.
   /// Can be null if version isn't set or has a wrong format.
   String get buildName {
     if (appVersion != null && appVersion.contains('+')) {
       return appVersion.split('+')?.elementAt(0);
     }
     return appVersion;
   }

   /// The build version number from the `pubspec.yaml` file.
   /// Can be null if version isn't set or has a wrong format.
   String get buildNumber {
     if (appVersion != null && appVersion.contains('+')) {
       final String value = appVersion.split('+')?.elementAt(1);
       return value;
     } else {
       return null;
     }
   }

   bool get usesMaterialDesign {
     return _flutterDescriptor['uses-material-design'] ?? false;
   }

   /// True if this Flutter module should use AndroidX dependencies.
   ///
   /// If false the deprecated Android Support library will be used.
   bool get usesAndroidX {
     return _flutterDescriptor['module']['androidX'] ?? false;
   }

   /// True if this manifest declares a Flutter module project.
   ///
   /// A Flutter project is considered a module when it has a `module:`
   /// descriptor. A Flutter module project supports integration into an
   /// existing host app, and has managed platform host code.
   ///
   /// Such a project can be created using `flutter create -t module`.
   bool get isModule => _flutterDescriptor.containsKey('module');

   /// True if this manifest declares a Flutter plugin project.
   ///
   /// A Flutter project is considered a plugin when it has a `plugin:`
   /// descriptor. A Flutter plugin project wraps custom Android and/or
   /// iOS code in a Dart interface for consumption by other Flutter app
   /// projects.
   ///
   /// Such a project can be created using `flutter create -t plugin`.
   bool get isPlugin => _flutterDescriptor.containsKey('plugin');

   /// Returns the Android package declared by this manifest in its
   /// module or plugin descriptor. Returns null, if there is no
   /// such declaration.
   String get androidPackage {
     if (isModule) {
       return _flutterDescriptor['module']['androidPackage'];
     }
     if (isPlugin) {
       final YamlMap plugin = _flutterDescriptor['plugin'];
       if (plugin.containsKey('platforms')) {
         return plugin['platforms']['android']['package'];
       } else {
         return plugin['androidPackage'];
       }
     }
     return null;
   }

   /// Returns the iOS bundle identifier declared by this manifest in its
   /// module descriptor. Returns null if there is no such declaration.
   String get iosBundleIdentifier {
     if (isModule) {
       return _flutterDescriptor['module']['iosBundleIdentifier'];
     }
     return null;
   }

   List<Map<String, dynamic>> get fontsDescriptor {
     return fonts.map((Font font) => font.descriptor).toList();
   }

   List<Map<String, dynamic>> get _rawFontsDescriptor {
     final List<dynamic> fontList = _flutterDescriptor['fonts'];
     return fontList == null
         ? const <Map<String, dynamic>>[]
         : fontList.map<Map<String, dynamic>>(castStringKeyedMap).toList();
   }

   List<Uri> get assets {
     final List<dynamic> assets = _flutterDescriptor['assets'];
     if (assets == null) {
       return const <Uri>[];
     }
     return assets
         .cast<String>()
         .map<String>(Uri.encodeFull)
         ?.map<Uri>(Uri.parse)
         ?.toList();
   }

   List<Font> _fonts;

   List<Font> get fonts {
     _fonts ??= _extractFonts();
     return _fonts;
   }

   List<Font> _extractFonts() {
     if (!_flutterDescriptor.containsKey('fonts')) {
       return <Font>[];
     }

     final List<Font> fonts = <Font>[];
     for (Map<String, dynamic> fontFamily in _rawFontsDescriptor) {
       final List<dynamic> fontFiles = fontFamily['fonts'];
       final String familyName = fontFamily['family'];
       if (familyName == null) {
         printError('Warning: Missing family name for font.', emphasis: true);
         continue;
       }
       if (fontFiles == null) {
         printError('Warning: No fonts specified for font $familyName', emphasis: true);
         continue;
       }

       final List<FontAsset> fontAssets = <FontAsset>[];
       for (Map<dynamic, dynamic> fontFile in fontFiles) {
         final String asset = fontFile['asset'];
         if (asset == null) {
           printError('Warning: Missing asset in fonts for $familyName', emphasis: true);
           continue;
         }

         fontAssets.add(FontAsset(
           Uri.parse(asset),
           weight: fontFile['weight'],
           style: fontFile['style'],
         ));
       }
       if (fontAssets.isNotEmpty) {
         fonts.add(Font(fontFamily['family'], fontAssets));
       }
     }
     return fonts;
   }
 }

 class Font {
   Font(this.familyName, this.fontAssets)
     : assert(familyName != null),
       assert(fontAssets != null),
       assert(fontAssets.isNotEmpty);

   final String familyName;
   final List<FontAsset> fontAssets;

   Map<String, dynamic> get descriptor {
     return <String, dynamic>{
       'family': familyName,
       'fonts': fontAssets.map<Map<String, dynamic>>((FontAsset a) => a.descriptor).toList(),
     };
   }

   @override
   String toString() => '$runtimeType(family: $familyName, assets: $fontAssets)';
 }

 class FontAsset {
   FontAsset(this.assetUri, {this.weight, this.style})
     : assert(assetUri != null);

   final Uri assetUri;
   final int weight;
   final String style;

   Map<String, dynamic> get descriptor {
     final Map<String, dynamic> descriptor = <String, dynamic>{};
     if (weight != null) {
       descriptor['weight'] = weight;
     }

     if (style != null) {
       descriptor['style'] = style;
     }

     descriptor['asset'] = assetUri.path;
     return descriptor;
   }

   @override
   String toString() => '$runtimeType(asset: ${assetUri.path}, weight; $weight, style: $style)';
 }

 @visibleForTesting
 String buildSchemaDir(FileSystem fs) {
   return fs.path.join(
     fs.path.absolute(Cache.flutterRoot), 'packages', 'flutter_tools', 'schema',
   );
 }

 @visibleForTesting
 String buildSchemaPath(FileSystem fs) {
   return fs.path.join(
     buildSchemaDir(fs),
     'pubspec_yaml.json',
   );
 }

 /// This method should be kept in sync with the schema in
 /// `$FLUTTER_ROOT/packages/flutter_tools/schema/pubspec_yaml.json`,
 /// but avoid introducing depdendencies on packages for simple validation.
 bool _validate(YamlMap manifest) {
   final List<String> errors = <String>[];
   for (final MapEntry<dynamic, dynamic> kvp in manifest.entries) {
     if (kvp.key is! String) {
       errors.add('Expected YAML key to be a a string, but got ${kvp.key}.');
       continue;
     }
     switch (kvp.key) {
       case 'name':
         if (kvp.value is! String) {
           errors.add('Expected "${kvp.key}" to be a string, but got ${kvp.value}.');
         }
         break;
       case 'flutter':
         if (kvp.value == null) {
           continue;
         }
         if (kvp.value is! YamlMap) {
           errors.add('Expected "${kvp.key}" section to be an object or null, but got ${kvp.value}.');
         }
         _validateFlutter(kvp.value, errors);
         break;
       default:
         // additionalProperties are allowed.
         break;
     }
   }

   if (errors.isNotEmpty) {
     printStatus('Error detected in pubspec.yaml:', emphasis: true);
     printError(errors.join('\n'));
     return false;
   }

   return true;
 }

 void _validateFlutter(YamlMap yaml, List<String> errors) {
   if (yaml == null || yaml.entries == null) {
     return;
   }
   for (final MapEntry<dynamic, dynamic> kvp in yaml.entries) {
     if (kvp.key is! String) {
       errors.add('Expected YAML key to be a a string, but got ${kvp.key} (${kvp.value.runtimeType}).');
       continue;
     }
     switch (kvp.key) {
       case 'uses-material-design':
         if (kvp.value is! bool) {
           errors.add('Expected "${kvp.key}" to be a bool, but got ${kvp.value} (${kvp.value.runtimeType}).');
         }
         break;
       case 'assets':
       case 'services':
         if (kvp.value is! YamlList || kvp.value[0] is! String) {
           errors.add('Expected "${kvp.key}" to be a list, but got ${kvp.value} (${kvp.value.runtimeType}).');
         }
         break;
       case 'fonts':
         if (kvp.value is! YamlList || kvp.value[0] is! YamlMap) {
           errors.add('Expected "${kvp.key}" to be a list, but got ${kvp.value} (${kvp.value.runtimeType}).');
         } else {
           _validateFonts(kvp.value, errors);
         }
         break;
       case 'module':
         if (kvp.value is! YamlMap) {
           errors.add('Expected "${kvp.key}" to be an object, but got ${kvp.value} (${kvp.value.runtimeType}).');
         }

         if (kvp.value['androidX'] != null && kvp.value['androidX'] is! bool) {
           errors.add('The "androidX" value must be a bool if set.');
         }
         if (kvp.value['androidPackage'] != null && kvp.value['androidPackage'] is! String) {
           errors.add('The "androidPackage" value must be a string if set.');
         }
         if (kvp.value['iosBundleIdentifier'] != null && kvp.value['iosBundleIdentifier'] is! String) {
           errors.add('The "iosBundleIdentifier" section must be a string if set.');
         }
         break;
       case 'plugin':
         if (kvp.value is! YamlMap) {
           errors.add('Expected "${kvp.key}" to be an object, but got ${kvp.value} (${kvp.value.runtimeType}).');
         }
         final List<String> pluginErrors = Plugin.validatePluginYaml(kvp.value);
         errors.addAll(pluginErrors);
         break;
       default:
         errors.add('Unexpected child "${kvp.key}" found under "flutter".');
         break;
     }
   }
 }

 void _validateFonts(YamlList fonts, List<String> errors) {
   if (fonts == null) {
     return;
   }
   const Set<int> fontWeights = <int>{
     100, 200, 300, 400, 500, 600, 700, 800, 900,
   };
   for (final dynamic fontListEntry in fonts) {
     if (fontListEntry is! YamlMap) {
       errors.add('Unexpected child "$fontListEntry" found under "fonts". Expected a map.');
       continue;
     }
     final YamlMap fontMap = fontListEntry;
     for (dynamic key in fontMap.keys.where((dynamic key) => key != 'family' && key != 'fonts')) {
       errors.add('Unexpected child "$key" found under "fonts".');
     }
     if (fontMap['family'] != null && fontMap['family'] is! String) {
       errors.add('Font family must either be null or a String.');
     }
     if (fontMap['fonts'] == null) {
       continue;
     } else if (fontMap['fonts'] is! YamlList) {
       errors.add('Expected "fonts" to either be null or a list.');
       continue;
     }
     for (final YamlMap fontListItem in fontMap['fonts']) {
       for (final MapEntry<dynamic, dynamic> kvp in fontListItem.entries) {
         if (kvp.key is! String) {
           errors.add('Expected "${kvp.key}" under "fonts" to be a string.');
         }
         switch(kvp.key) {
           case 'asset':
             if (kvp.value is! String) {
               errors.add('Expected font asset ${kvp.value} ((${kvp.value.runtimeType})) to be a string.');
             }
             break;
           case 'weight':
             if (!fontWeights.contains(kvp.value)) {
               errors.add('Invalid value ${kvp.value} ((${kvp.value.runtimeType})) for font -> weight.');
             }
             break;
           case 'style':
             if (kvp.value != 'normal' && kvp.value != 'italic') {
               errors.add('Invalid value ${kvp.value} ((${kvp.value.runtimeType})) for font -> style.');
             }
             break;
           default:
             errors.add('Unexpected key ${kvp.key} ((${kvp.value.runtimeType})) under font.');
             break;
         }
       }
     }
   }
 }
	// Copyright 2017 The Chromium 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 'package:meta/meta.dart';
	import 'package:pub_semver/pub_semver.dart';
	import 'package:yaml/yaml.dart';

	import 'base/file_system.dart';
	import 'base/user_messages.dart';
	import 'base/utils.dart';
	import 'cache.dart';
	import 'globals.dart';
	import 'plugins.dart';

	/// A wrapper around the `flutter` section in the `pubspec.yaml` file.
	class FlutterManifest {
	FlutterManifest._();

	/// Returns an empty manifest.
	static FlutterManifest empty() {
	final FlutterManifest manifest = FlutterManifest._();
	manifest._descriptor = const <String, dynamic>{};
	manifest._flutterDescriptor = const <String, dynamic>{};
	return manifest;
	}

	/// Returns null on invalid manifest. Returns empty manifest on missing file.
	static FlutterManifest createFromPath(String path) {
	if (path == null \|\| !fs.isFileSync(path)) {
	return _createFromYaml(null);
	}
	final String manifest = fs.file(path).readAsStringSync();
	return createFromString(manifest);
	}

	/// Returns null on missing or invalid manifest
	@visibleForTesting
	static FlutterManifest createFromString(String manifest) {
	return _createFromYaml(loadYaml(manifest));
	}

	static FlutterManifest _createFromYaml(dynamic yamlDocument) {
	final FlutterManifest pubspec = FlutterManifest._();
	if (yamlDocument != null && !_validate(yamlDocument)) {
	return null;
	}

	final Map<dynamic, dynamic> yamlMap = yamlDocument;
	if (yamlMap != null) {
	pubspec._descriptor = yamlMap.cast<String, dynamic>();
	} else {
	pubspec._descriptor = <String, dynamic>{};
	}

	final Map<dynamic, dynamic> flutterMap = pubspec._descriptor['flutter'];
	if (flutterMap != null) {
	pubspec._flutterDescriptor = flutterMap.cast<String, dynamic>();
	} else {
	pubspec._flutterDescriptor = <String, dynamic>{};
	}

	return pubspec;
	}

	/// A map representation of the entire `pubspec.yaml` file.
	Map<String, dynamic> _descriptor;

	/// A map representation of the `flutter` section in the `pubspec.yaml` file.
	Map<String, dynamic> _flutterDescriptor;

	/// True if the `pubspec.yaml` file does not exist.
	bool get isEmpty => _descriptor.isEmpty;

	/// The string value of the top-level `name` property in the `pubspec.yaml` file.
	String get appName => _descriptor['name'] ?? '';

	// Flag to avoid printing multiple invalid version messages.
	bool _hasShowInvalidVersionMsg = false;

	/// The version String from the `pubspec.yaml` file.
	/// Can be null if it isn't set or has a wrong format.
	String get appVersion {
	final String verStr = _descriptor['version']?.toString();
	if (verStr == null) {
	return null;
	}

	Version version;
	try {
	version = Version.parse(verStr);
	} on Exception {
	if (!_hasShowInvalidVersionMsg) {
	printStatus(userMessages.invalidVersionSettingHintMessage(verStr), emphasis: true);
	_hasShowInvalidVersionMsg = true;
	}
	}
	return version?.toString();
	}

	/// The build version name from the `pubspec.yaml` file.
	/// Can be null if version isn't set or has a wrong format.
	String get buildName {
	if (appVersion != null && appVersion.contains('+')) {
	return appVersion.split('+')?.elementAt(0);
	}
	return appVersion;
	}

	/// The build version number from the `pubspec.yaml` file.
	/// Can be null if version isn't set or has a wrong format.
	String get buildNumber {
	if (appVersion != null && appVersion.contains('+')) {
	final String value = appVersion.split('+')?.elementAt(1);
	return value;
	} else {
	return null;
	}
	}

	bool get usesMaterialDesign {
	return _flutterDescriptor['uses-material-design'] ?? false;
	}

	/// True if this Flutter module should use AndroidX dependencies.
	///
	/// If false the deprecated Android Support library will be used.
	bool get usesAndroidX {
	return _flutterDescriptor['module']['androidX'] ?? false;
	}

	/// True if this manifest declares a Flutter module project.
	///
	/// A Flutter project is considered a module when it has a `module:`
	/// descriptor. A Flutter module project supports integration into an
	/// existing host app, and has managed platform host code.
	///
	/// Such a project can be created using `flutter create -t module`.
	bool get isModule => _flutterDescriptor.containsKey('module');

	/// True if this manifest declares a Flutter plugin project.
	///
	/// A Flutter project is considered a plugin when it has a `plugin:`
	/// descriptor. A Flutter plugin project wraps custom Android and/or
	/// iOS code in a Dart interface for consumption by other Flutter app
	/// projects.
	///
	/// Such a project can be created using `flutter create -t plugin`.
	bool get isPlugin => _flutterDescriptor.containsKey('plugin');

	/// Returns the Android package declared by this manifest in its
	/// module or plugin descriptor. Returns null, if there is no
	/// such declaration.
	String get androidPackage {
	if (isModule) {
	return _flutterDescriptor['module']['androidPackage'];
	}
	if (isPlugin) {
	final YamlMap plugin = _flutterDescriptor['plugin'];
	if (plugin.containsKey('platforms')) {
	return plugin['platforms']['android']['package'];
	} else {
	return plugin['androidPackage'];
	}
	}
	return null;
	}

	/// Returns the iOS bundle identifier declared by this manifest in its
	/// module descriptor. Returns null if there is no such declaration.
	String get iosBundleIdentifier {
	if (isModule) {
	return _flutterDescriptor['module']['iosBundleIdentifier'];
	}
	return null;
	}

	List<Map<String, dynamic>> get fontsDescriptor {
	return fonts.map((Font font) => font.descriptor).toList();
	}

	List<Map<String, dynamic>> get _rawFontsDescriptor {
	final List<dynamic> fontList = _flutterDescriptor['fonts'];
	return fontList == null
	? const <Map<String, dynamic>>[]
	: fontList.map<Map<String, dynamic>>(castStringKeyedMap).toList();
	}

	List<Uri> get assets {
	final List<dynamic> assets = _flutterDescriptor['assets'];
	if (assets == null) {
	return const <Uri>[];
	}
	return assets
	.cast<String>()
	.map<String>(Uri.encodeFull)
	?.map<Uri>(Uri.parse)
	?.toList();
	}

	List<Font> _fonts;

	List<Font> get fonts {
	_fonts ??= _extractFonts();
	return _fonts;
	}

	List<Font> _extractFonts() {
	if (!_flutterDescriptor.containsKey('fonts')) {
	return <Font>[];
	}

	final List<Font> fonts = <Font>[];
	for (Map<String, dynamic> fontFamily in _rawFontsDescriptor) {
	final List<dynamic> fontFiles = fontFamily['fonts'];
	final String familyName = fontFamily['family'];
	if (familyName == null) {
	printError('Warning: Missing family name for font.', emphasis: true);
	continue;
	}
	if (fontFiles == null) {
	printError('Warning: No fonts specified for font $familyName', emphasis: true);
	continue;
	}

	final List<FontAsset> fontAssets = <FontAsset>[];
	for (Map<dynamic, dynamic> fontFile in fontFiles) {
	final String asset = fontFile['asset'];
	if (asset == null) {
	printError('Warning: Missing asset in fonts for $familyName', emphasis: true);
	continue;
	}

	fontAssets.add(FontAsset(
	Uri.parse(asset),
	weight: fontFile['weight'],
	style: fontFile['style'],
	));
	}
	if (fontAssets.isNotEmpty) {
	fonts.add(Font(fontFamily['family'], fontAssets));
	}
	}
	return fonts;
	}
	}

	class Font {
	Font(this.familyName, this.fontAssets)
	: assert(familyName != null),
	assert(fontAssets != null),
	assert(fontAssets.isNotEmpty);

	final String familyName;
	final List<FontAsset> fontAssets;

	Map<String, dynamic> get descriptor {
	return <String, dynamic>{
	'family': familyName,
	'fonts': fontAssets.map<Map<String, dynamic>>((FontAsset a) => a.descriptor).toList(),
	};
	}

	@override
	String toString() => '$runtimeType(family: $familyName, assets: $fontAssets)';
	}

	class FontAsset {
	FontAsset(this.assetUri, {this.weight, this.style})
	: assert(assetUri != null);

	final Uri assetUri;
	final int weight;
	final String style;

	Map<String, dynamic> get descriptor {
	final Map<String, dynamic> descriptor = <String, dynamic>{};
	if (weight != null) {
	descriptor['weight'] = weight;
	}

	if (style != null) {
	descriptor['style'] = style;
	}

	descriptor['asset'] = assetUri.path;
	return descriptor;
	}

	@override
	String toString() => '$runtimeType(asset: ${assetUri.path}, weight; $weight, style: $style)';
	}

	@visibleForTesting
	String buildSchemaDir(FileSystem fs) {
	return fs.path.join(
	fs.path.absolute(Cache.flutterRoot), 'packages', 'flutter_tools', 'schema',
	);
	}

	@visibleForTesting
	String buildSchemaPath(FileSystem fs) {
	return fs.path.join(
	buildSchemaDir(fs),
	'pubspec_yaml.json',
	);
	}

	/// This method should be kept in sync with the schema in
	/// `$FLUTTER_ROOT/packages/flutter_tools/schema/pubspec_yaml.json`,
	/// but avoid introducing depdendencies on packages for simple validation.
	bool _validate(YamlMap manifest) {
	final List<String> errors = <String>[];
	for (final MapEntry<dynamic, dynamic> kvp in manifest.entries) {
	if (kvp.key is! String) {
	errors.add('Expected YAML key to be a a string, but got ${kvp.key}.');
	continue;
	}
	switch (kvp.key) {
	case 'name':
	if (kvp.value is! String) {
	errors.add('Expected "${kvp.key}" to be a string, but got ${kvp.value}.');
	}
	break;
	case 'flutter':
	if (kvp.value == null) {
	continue;
	}
	if (kvp.value is! YamlMap) {
	errors.add('Expected "${kvp.key}" section to be an object or null, but got ${kvp.value}.');
	}
	_validateFlutter(kvp.value, errors);
	break;
	default:
	// additionalProperties are allowed.
	break;
	}
	}

	if (errors.isNotEmpty) {
	printStatus('Error detected in pubspec.yaml:', emphasis: true);
	printError(errors.join('\n'));
	return false;
	}

	return true;
	}

	void _validateFlutter(YamlMap yaml, List<String> errors) {
	if (yaml == null \|\| yaml.entries == null) {
	return;
	}
	for (final MapEntry<dynamic, dynamic> kvp in yaml.entries) {
	if (kvp.key is! String) {
	errors.add('Expected YAML key to be a a string, but got ${kvp.key} (${kvp.value.runtimeType}).');
	continue;
	}
	switch (kvp.key) {
	case 'uses-material-design':
	if (kvp.value is! bool) {
	errors.add('Expected "${kvp.key}" to be a bool, but got ${kvp.value} (${kvp.value.runtimeType}).');
	}
	break;
	case 'assets':
	case 'services':
	if (kvp.value is! YamlList \|\| kvp.value[0] is! String) {
	errors.add('Expected "${kvp.key}" to be a list, but got ${kvp.value} (${kvp.value.runtimeType}).');
	}
	break;
	case 'fonts':
	if (kvp.value is! YamlList \|\| kvp.value[0] is! YamlMap) {
	errors.add('Expected "${kvp.key}" to be a list, but got ${kvp.value} (${kvp.value.runtimeType}).');
	} else {
	_validateFonts(kvp.value, errors);
	}
	break;
	case 'module':
	if (kvp.value is! YamlMap) {
	errors.add('Expected "${kvp.key}" to be an object, but got ${kvp.value} (${kvp.value.runtimeType}).');
	}

	if (kvp.value['androidX'] != null && kvp.value['androidX'] is! bool) {
	errors.add('The "androidX" value must be a bool if set.');
	}
	if (kvp.value['androidPackage'] != null && kvp.value['androidPackage'] is! String) {
	errors.add('The "androidPackage" value must be a string if set.');
	}
	if (kvp.value['iosBundleIdentifier'] != null && kvp.value['iosBundleIdentifier'] is! String) {
	errors.add('The "iosBundleIdentifier" section must be a string if set.');
	}
	break;
	case 'plugin':
	if (kvp.value is! YamlMap) {
	errors.add('Expected "${kvp.key}" to be an object, but got ${kvp.value} (${kvp.value.runtimeType}).');
	}
	final List<String> pluginErrors = Plugin.validatePluginYaml(kvp.value);
	errors.addAll(pluginErrors);
	break;
	default:
	errors.add('Unexpected child "${kvp.key}" found under "flutter".');
	break;
	}
	}
	}

	void _validateFonts(YamlList fonts, List<String> errors) {
	if (fonts == null) {
	return;
	}
	const Set<int> fontWeights = <int>{
	100, 200, 300, 400, 500, 600, 700, 800, 900,
	};
	for (final dynamic fontListEntry in fonts) {
	if (fontListEntry is! YamlMap) {
	errors.add('Unexpected child "$fontListEntry" found under "fonts". Expected a map.');
	continue;
	}
	final YamlMap fontMap = fontListEntry;
	for (dynamic key in fontMap.keys.where((dynamic key) => key != 'family' && key != 'fonts')) {
	errors.add('Unexpected child "$key" found under "fonts".');
	}
	if (fontMap['family'] != null && fontMap['family'] is! String) {
	errors.add('Font family must either be null or a String.');
	}
	if (fontMap['fonts'] == null) {
	continue;
	} else if (fontMap['fonts'] is! YamlList) {
	errors.add('Expected "fonts" to either be null or a list.');
	continue;
	}
	for (final YamlMap fontListItem in fontMap['fonts']) {
	for (final MapEntry<dynamic, dynamic> kvp in fontListItem.entries) {
	if (kvp.key is! String) {
	errors.add('Expected "${kvp.key}" under "fonts" to be a string.');
	}
	switch(kvp.key) {
	case 'asset':
	if (kvp.value is! String) {
	errors.add('Expected font asset ${kvp.value} ((${kvp.value.runtimeType})) to be a string.');
	}
	break;
	case 'weight':
	if (!fontWeights.contains(kvp.value)) {
	errors.add('Invalid value ${kvp.value} ((${kvp.value.runtimeType})) for font -> weight.');
	}
	break;
	case 'style':
	if (kvp.value != 'normal' && kvp.value != 'italic') {
	errors.add('Invalid value ${kvp.value} ((${kvp.value.runtimeType})) for font -> style.');
	}
	break;
	default:
	errors.add('Unexpected key ${kvp.key} ((${kvp.value.runtimeType})) under font.');
	break;
	}
	}
	}
	}
	}