packages/go_router_builder/lib/src/route_config.dart - mirrors/packages - Git at Google

 // Copyright 2013 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:collection';

 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:collection/collection.dart';
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as p;
 import 'package:source_gen/source_gen.dart';
 import 'package:source_helper/source_helper.dart';

 import 'path_utils.dart';
 import 'type_helpers.dart';

 /// Custom [Iterable] implementation with extra info.
 class InfoIterable extends IterableBase<String> {
   InfoIterable._({
     required this.members,
     required this.routeGetterName,
   });

   /// Name of the getter associated with `this`.
   final String routeGetterName;

   /// The generated elements associated with `this`.
   final List<String> members;

   @override
   Iterator<String> get iterator => members.iterator;
 }

 /// The configuration to generate class declarations for a ShellRouteData.
 class ShellRouteConfig extends RouteBaseConfig {
   ShellRouteConfig._({
     required this.navigatorKey,
     required super.routeDataClass,
     required super.parent,
     required super.parentNavigatorKey,
   }) : super._();

   /// The command for calling the navigator key getter from the ShellRouteData.
   final String? navigatorKey;

   @override
   Iterable<String> classDeclarations() {
     if (routeDataClass.unnamedConstructor == null) {
       throw InvalidGenerationSourceError(
         'The ShellRouteData "$_className" class must have an unnamed constructor.',
         element: routeDataClass,
       );
     }

     final bool isConst = routeDataClass.unnamedConstructor!.isConst;

     return <String>[
       '''
   extension $_extensionName on $_className {
   static $_className _fromState(GoRouterState state) =>${isConst ? ' const' : ''} $_className();
   }
   '''
     ];
   }

   @override
   String get routeConstructorParameters =>
       navigatorKey == null ? '' : 'navigatorKey: $navigatorKey,';

   @override
   String get routeDataClassName => 'ShellRouteData';
 }

 /// The configuration to generate class declarations for a GoRouteData.
 class GoRouteConfig extends RouteBaseConfig {
   GoRouteConfig._({
     required this.path,
     required this.name,
     required super.routeDataClass,
     required super.parent,
     required super.parentNavigatorKey,
   }) : super._();

   /// The path of the GoRoute to be created by this configuration.
   final String path;

   /// The name of the GoRoute to be created by this configuration.
   final String? name;

   late final Set<String> _pathParams =
       pathParametersFromPattern(_rawJoinedPath);

   String get _rawJoinedPath {
     final List<String> pathSegments = <String>[];

     RouteBaseConfig? config = this;
     while (config != null) {
       if (config is GoRouteConfig) {
         pathSegments.add(config.path);
       }
       config = config.parent;
     }

     return p.url.joinAll(pathSegments.reversed);
   }

   // construct path bits using parent bits
   // if there are any queryParam objects, add in the `queryParam` bits
   String get _locationArgs {
     final Map<String, String> pathParameters = Map<String, String>.fromEntries(
       _pathParams.map((String pathParameter) {
         // Enum types are encoded using a map, so we need a nullability check
         // here to ensure it matches Uri.encodeComponent nullability
         final DartType? type = _field(pathParameter)?.returnType;
         final String value =
             '\${Uri.encodeComponent(${_encodeFor(pathParameter)}${type?.isEnum ?? false ? '!' : ''})}';
         return MapEntry<String, String>(pathParameter, value);
       }),
     );
     final String location = patternToPath(_rawJoinedPath, pathParameters);
     return "'$location'";
   }

   ParameterElement? get _extraParam => _ctor.parameters
       .singleWhereOrNull((ParameterElement element) => element.isExtraField);

   String get _fromStateConstructor {
     final StringBuffer buffer = StringBuffer('=>');
     if (_ctor.isConst &&
         _ctorParams.isEmpty &&
         _ctorQueryParams.isEmpty &&
         _extraParam == null) {
       buffer.writeln('const ');
     }

     buffer.writeln('$_className(');
     for (final ParameterElement param in <ParameterElement>[
       ..._ctorParams,
       ..._ctorQueryParams,
       if (_extraParam != null) _extraParam!,
     ]) {
       buffer.write(_decodeFor(param));
     }
     buffer.writeln(');');

     return buffer.toString();
   }

   String _decodeFor(ParameterElement element) {
     if (element.isRequired) {
       if (element.type.nullabilitySuffix == NullabilitySuffix.question &&
           _pathParams.contains(element.name)) {
         throw InvalidGenerationSourceError(
           'Required parameters in the path cannot be nullable.',
           element: element,
         );
       }
     }
     final String fromStateExpression = decodeParameter(element, _pathParams);

     if (element.isPositional) {
       return '$fromStateExpression,';
     }

     if (element.isNamed) {
       return '${element.name}: $fromStateExpression,';
     }

     throw InvalidGenerationSourceError(
       '$likelyIssueMessage (param not named or positional)',
       element: element,
     );
   }

   String _encodeFor(String fieldName) {
     final PropertyAccessorElement? field = _field(fieldName);
     if (field == null) {
       throw InvalidGenerationSourceError(
         'Could not find a field for the path parameter "$fieldName".',
         element: routeDataClass,
       );
     }

     return encodeField(field);
   }

   String get _locationQueryParams {
     if (_ctorQueryParams.isEmpty) {
       return '';
     }

     final StringBuffer buffer = StringBuffer('queryParams: {\n');

     for (final ParameterElement param in _ctorQueryParams) {
       final String parameterName = param.name;

       final List<String> conditions = <String>[];
       if (param.hasDefaultValue) {
         if (param.type.isNullableType) {
           throw NullableDefaultValueError(param);
         }
         conditions.add('$parameterName != ${param.defaultValueCode!}');
       } else if (param.type.isNullableType) {
         conditions.add('$parameterName != null');
       }
       String line = '';
       if (conditions.isNotEmpty) {
         line = 'if (${conditions.join(' && ')}) ';
       }
       line += '${escapeDartString(parameterName.kebab)}: '
           '${_encodeFor(parameterName)},';

       buffer.writeln(line);
     }

     buffer.writeln('},');

     return buffer.toString();
   }

   late final List<ParameterElement> _ctorParams =
       _ctor.parameters.where((ParameterElement element) {
     if (_pathParams.contains(element.name)) {
       return true;
     }
     return false;
   }).toList();

   late final List<ParameterElement> _ctorQueryParams = _ctor.parameters
       .where((ParameterElement element) =>
           !_pathParams.contains(element.name) && !element.isExtraField)
       .toList();

   ConstructorElement get _ctor {
     final ConstructorElement? ctor = routeDataClass.unnamedConstructor;

     if (ctor == null) {
       throw InvalidGenerationSourceError(
         'Missing default constructor',
         element: routeDataClass,
       );
     }
     return ctor;
   }

   @override
   Iterable<String> classDeclarations() => <String>[
         _extensionDefinition,
         ..._enumDeclarations(),
       ];

   String get _extensionDefinition => '''
 extension $_extensionName on $_className {
   static $_className _fromState(GoRouterState state) $_fromStateConstructor

   String get location => GoRouteData.\$location($_locationArgs,$_locationQueryParams);

   void go(BuildContext context) =>
       context.go(location${_extraParam != null ? ', extra: $extraFieldName' : ''});

   Future<T?> push<T>(BuildContext context) =>
       context.push<T>(location${_extraParam != null ? ', extra: $extraFieldName' : ''});

   void pushReplacement(BuildContext context) =>
       context.pushReplacement(location${_extraParam != null ? ', extra: $extraFieldName' : ''});

   void replace(BuildContext context) =>
       context.replace(location${_extraParam != null ? ', extra: $extraFieldName' : ''});
 }
 ''';

   /// Returns code representing the constant maps that contain the `enum` to
   /// [String] mapping for each referenced enum.
   Iterable<String> _enumDeclarations() {
     final Set<InterfaceType> enumParamTypes = <InterfaceType>{};

     for (final ParameterElement ctorParam in <ParameterElement>[
       ..._ctorParams,
       ..._ctorQueryParams,
     ]) {
       DartType potentialEnumType = ctorParam.type;
       if (potentialEnumType is ParameterizedType &&
           (ctorParam.type as ParameterizedType).typeArguments.isNotEmpty) {
         potentialEnumType =
             (ctorParam.type as ParameterizedType).typeArguments.first;
       }

       if (potentialEnumType.isEnum) {
         enumParamTypes.add(potentialEnumType as InterfaceType);
       }
     }
     return enumParamTypes.map<String>(_enumMapConst);
   }

   @override
   String get routeConstructorParameters => '''
     path: ${escapeDartString(path)},
     ${name != null ? 'name: ${escapeDartString(name!)},' : ''}
 ''';

   @override
   String get routeDataClassName => 'GoRouteData';
 }

 /// Represents a `TypedGoRoute` annotation to the builder.
 abstract class RouteBaseConfig {
   RouteBaseConfig._({
     required this.routeDataClass,
     required this.parent,
     required this.parentNavigatorKey,
   });

   /// Creates a new [RouteBaseConfig] represented the annotation data in [reader].
   factory RouteBaseConfig.fromAnnotation(
     ConstantReader reader,
     InterfaceElement element,
   ) {
     final RouteBaseConfig definition =
         RouteBaseConfig._fromAnnotation(reader, element, null);

     if (element != definition.routeDataClass) {
       throw InvalidGenerationSourceError(
         'The @TypedGoRoute annotation must have a type parameter that matches '
         'the annotated element.',
         element: element,
       );
     }

     return definition;
   }

   factory RouteBaseConfig._fromAnnotation(
     ConstantReader reader,
     InterfaceElement element,
     RouteBaseConfig? parent,
   ) {
     assert(!reader.isNull, 'reader should not be null');
     final InterfaceType type = reader.objectValue.type! as InterfaceType;
     // TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
     // 5.2+ (when Flutter 3.4+ is on stable).
     // ignore: deprecated_member_use
     final bool isShellRoute = type.element.name == 'TypedShellRoute';
     final DartType typeParamType = type.typeArguments.single;
     if (typeParamType is! InterfaceType) {
       throw InvalidGenerationSourceError(
         'The type parameter on one of the @TypedGoRoute declarations could not '
         'be parsed.',
         element: element,
       );
     }

     // TODO(kevmoo): validate that this MUST be a subtype of `GoRouteData`
     // TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
     // 5.2+ (when Flutter 3.4+ is on stable).
     // ignore: deprecated_member_use
     final InterfaceElement classElement = typeParamType.element;

     final RouteBaseConfig value;
     if (isShellRoute) {
       value = ShellRouteConfig._(
         routeDataClass: classElement,
         parent: parent,
         navigatorKey: _generateNavigatorKeyGetterCode(
           classElement,
           keyName: r'$navigatorKey',
         ),
         parentNavigatorKey: _generateNavigatorKeyGetterCode(
           classElement,
           keyName: r'$parentNavigatorKey',
         ),
       );
     } else {
       final ConstantReader pathValue = reader.read('path');
       if (pathValue.isNull) {
         throw InvalidGenerationSourceError(
           'Missing `path` value on annotation.',
           element: element,
         );
       }

       final ConstantReader nameValue = reader.read('name');
       value = GoRouteConfig._(
         path: pathValue.stringValue,
         name: nameValue.isNull ? null : nameValue.stringValue,
         routeDataClass: classElement,
         parent: parent,
         parentNavigatorKey: _generateNavigatorKeyGetterCode(
           classElement,
           keyName: r'$parentNavigatorKey',
         ),
       );
     }

     value._children.addAll(reader.read('routes').listValue.map<RouteBaseConfig>(
         (DartObject e) => RouteBaseConfig._fromAnnotation(
             ConstantReader(e), element, value)));

     return value;
   }

   final List<RouteBaseConfig> _children = <RouteBaseConfig>[];

   /// The `RouteData` class this class represents.
   final InterfaceElement routeDataClass;

   /// The parent of this route config.
   final RouteBaseConfig? parent;

   /// The parent navigator key string that is used for initialize the
   /// `RouteBase` class this config generates.
   final String? parentNavigatorKey;

   static String? _generateNavigatorKeyGetterCode(
     InterfaceElement classElement, {
     required String keyName,
   }) {
     final String? fieldDisplayName = classElement.fields
         .where((FieldElement element) {
           final DartType type = element.type;
           if (!element.isStatic ||
               element.name != keyName ||
               type is! ParameterizedType) {
             return false;
           }
           final List<DartType> typeArguments = type.typeArguments;
           if (typeArguments.length != 1) {
             return false;
           }
           final DartType typeArgument = typeArguments.single;
           if (typeArgument.getDisplayString(withNullability: false) ==
               'NavigatorState') {
             return true;
           }
           return false;
         })
         .map<String>((FieldElement e) => e.displayName)
         .firstOrNull;

     if (fieldDisplayName == null) {
       return null;
     }
     return '${classElement.name}.$fieldDisplayName';
   }

   /// Generates all of the members that correspond to `this`.
   InfoIterable generateMembers() => InfoIterable._(
         members: _generateMembers().toList(),
         routeGetterName: _routeGetterName,
       );

   Iterable<String> _generateMembers() sync* {
     final List<String> items = <String>[
       _rootDefinition(),
     ];

     for (final RouteBaseConfig def in _flatten()) {
       items.addAll(def.classDeclarations());
     }

     yield* items;

     yield* items
         .expand(
           (String e) => helperNames.entries
               .where(
                   (MapEntry<String, String> element) => e.contains(element.key))
               .map((MapEntry<String, String> e) => e.value),
         )
         .toSet();
   }

   /// Returns this [GoRouteConfig] and all child [GoRouteConfig] instances.
   Iterable<RouteBaseConfig> _flatten() sync* {
     yield this;
     for (final RouteBaseConfig child in _children) {
       yield* child._flatten();
     }
   }

   late final String _routeGetterName =
       r'$' + _className.substring(0, 1).toLowerCase() + _className.substring(1);

   /// Returns the `GoRoute` code for the annotated class.
   String _rootDefinition() => '''
 RouteBase get $_routeGetterName => ${_invokesRouteConstructor()};
 ''';

   String get _className => routeDataClass.name;

   String get _extensionName => '\$${_className}Extension';

   String _invokesRouteConstructor() {
     final String routesBit = _children.isEmpty
         ? ''
         : '''
 routes: [${_children.map((RouteBaseConfig e) => '${e._invokesRouteConstructor()},').join()}],
 ''';
     final String parentNavigatorKeyParameter = parentNavigatorKey == null
         ? ''
         : 'parentNavigatorKey: $parentNavigatorKey,';
     return '''
 $routeDataClassName.\$route(
     $routeConstructorParameters
     factory: $_extensionName._fromState,
     $parentNavigatorKeyParameter
     $routesBit
   )
 ''';
   }

   PropertyAccessorElement? _field(String name) =>
       routeDataClass.getGetter(name);

   /// The name of `RouteData` subclass this configuration represents.
   @protected
   String get routeDataClassName;

   /// Additional constructor parameter for invoking route constructor.
   @protected
   String get routeConstructorParameters;

   /// Returns all class declarations code.
   @protected
   Iterable<String> classDeclarations();
 }

 String _enumMapConst(InterfaceType type) {
   assert(type.isEnum);

   // TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
   // 5.2+ (when Flutter 3.4+ is on stable).
   // ignore: deprecated_member_use
   final String enumName = type.element.name;

   final StringBuffer buffer = StringBuffer('const ${enumMapName(type)} = {');

   // TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
   // 5.2+ (when Flutter 3.4+ is on stable).
   // ignore: deprecated_member_use
   for (final FieldElement enumField in type.element.fields
       .where((FieldElement element) => element.isEnumConstant)) {
     buffer.writeln(
       '$enumName.${enumField.name}: ${escapeDartString(enumField.name.kebab)},',
     );
   }

   buffer.writeln('};');

   return buffer.toString();
 }

 /// [Map] from the name of a generated helper to its definition.
 const Map<String, String> helperNames = <String, String>{
   convertMapValueHelperName: _convertMapValueHelper,
   boolConverterHelperName: _boolConverterHelper,
   enumExtensionHelperName: _enumConverterHelper,
 };

 const String _convertMapValueHelper = '''
 T? $convertMapValueHelperName<T>(
   String key,
   Map<String, String> map,
   T Function(String) converter,
 ) {
   final value = map[key];
   return value == null ? null : converter(value);
 }
 ''';

 const String _boolConverterHelper = '''
 bool $boolConverterHelperName(String value) {
   switch (value) {
     case 'true':
       return true;
     case 'false':
       return false;
     default:
       throw UnsupportedError('Cannot convert "\$value" into a bool.');
   }
 }
 ''';

 const String _enumConverterHelper = '''
 extension<T extends Enum> on Map<T, String> {
   T $enumExtensionHelperName(String value) =>
       entries.singleWhere((element) => element.value == value).key;
 }''';
	// Copyright 2013 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:collection';

	import 'package:analyzer/dart/constant/value.dart';
	import 'package:analyzer/dart/element/element.dart';
	import 'package:analyzer/dart/element/nullability_suffix.dart';
	import 'package:analyzer/dart/element/type.dart';
	import 'package:collection/collection.dart';
	import 'package:meta/meta.dart';
	import 'package:path/path.dart' as p;
	import 'package:source_gen/source_gen.dart';
	import 'package:source_helper/source_helper.dart';

	import 'path_utils.dart';
	import 'type_helpers.dart';

	/// Custom [Iterable] implementation with extra info.
	class InfoIterable extends IterableBase<String> {
	InfoIterable._({
	required this.members,
	required this.routeGetterName,
	});

	/// Name of the getter associated with `this`.
	final String routeGetterName;

	/// The generated elements associated with `this`.
	final List<String> members;

	@override
	Iterator<String> get iterator => members.iterator;
	}

	/// The configuration to generate class declarations for a ShellRouteData.
	class ShellRouteConfig extends RouteBaseConfig {
	ShellRouteConfig._({
	required this.navigatorKey,
	required super.routeDataClass,
	required super.parent,
	required super.parentNavigatorKey,
	}) : super._();

	/// The command for calling the navigator key getter from the ShellRouteData.
	final String? navigatorKey;

	@override
	Iterable<String> classDeclarations() {
	if (routeDataClass.unnamedConstructor == null) {
	throw InvalidGenerationSourceError(
	'The ShellRouteData "$_className" class must have an unnamed constructor.',
	element: routeDataClass,
	);
	}

	final bool isConst = routeDataClass.unnamedConstructor!.isConst;

	return <String>[
	'''
	extension $_extensionName on $_className {
	static $_className _fromState(GoRouterState state) =>${isConst ? ' const' : ''} $_className();
	}
	'''
	];
	}

	@override
	String get routeConstructorParameters =>
	navigatorKey == null ? '' : 'navigatorKey: $navigatorKey,';

	@override
	String get routeDataClassName => 'ShellRouteData';
	}

	/// The configuration to generate class declarations for a GoRouteData.
	class GoRouteConfig extends RouteBaseConfig {
	GoRouteConfig._({
	required this.path,
	required this.name,
	required super.routeDataClass,
	required super.parent,
	required super.parentNavigatorKey,
	}) : super._();

	/// The path of the GoRoute to be created by this configuration.
	final String path;

	/// The name of the GoRoute to be created by this configuration.
	final String? name;

	late final Set<String> _pathParams =
	pathParametersFromPattern(_rawJoinedPath);

	String get _rawJoinedPath {
	final List<String> pathSegments = <String>[];

	RouteBaseConfig? config = this;
	while (config != null) {
	if (config is GoRouteConfig) {
	pathSegments.add(config.path);
	}
	config = config.parent;
	}

	return p.url.joinAll(pathSegments.reversed);
	}

	// construct path bits using parent bits
	// if there are any queryParam objects, add in the `queryParam` bits
	String get _locationArgs {
	final Map<String, String> pathParameters = Map<String, String>.fromEntries(
	_pathParams.map((String pathParameter) {
	// Enum types are encoded using a map, so we need a nullability check
	// here to ensure it matches Uri.encodeComponent nullability
	final DartType? type = _field(pathParameter)?.returnType;
	final String value =
	'\${Uri.encodeComponent(${_encodeFor(pathParameter)}${type?.isEnum ?? false ? '!' : ''})}';
	return MapEntry<String, String>(pathParameter, value);
	}),
	);
	final String location = patternToPath(_rawJoinedPath, pathParameters);
	return "'$location'";
	}

	ParameterElement? get _extraParam => _ctor.parameters
	.singleWhereOrNull((ParameterElement element) => element.isExtraField);

	String get _fromStateConstructor {
	final StringBuffer buffer = StringBuffer('=>');
	if (_ctor.isConst &&
	_ctorParams.isEmpty &&
	_ctorQueryParams.isEmpty &&
	_extraParam == null) {
	buffer.writeln('const ');
	}

	buffer.writeln('$_className(');
	for (final ParameterElement param in <ParameterElement>[
	..._ctorParams,
	..._ctorQueryParams,
	if (_extraParam != null) _extraParam!,
	]) {
	buffer.write(_decodeFor(param));
	}
	buffer.writeln(');');

	return buffer.toString();
	}

	String _decodeFor(ParameterElement element) {
	if (element.isRequired) {
	if (element.type.nullabilitySuffix == NullabilitySuffix.question &&
	_pathParams.contains(element.name)) {
	throw InvalidGenerationSourceError(
	'Required parameters in the path cannot be nullable.',
	element: element,
	);
	}
	}
	final String fromStateExpression = decodeParameter(element, _pathParams);

	if (element.isPositional) {
	return '$fromStateExpression,';
	}

	if (element.isNamed) {
	return '${element.name}: $fromStateExpression,';
	}

	throw InvalidGenerationSourceError(
	'$likelyIssueMessage (param not named or positional)',
	element: element,
	);
	}

	String _encodeFor(String fieldName) {
	final PropertyAccessorElement? field = _field(fieldName);
	if (field == null) {
	throw InvalidGenerationSourceError(
	'Could not find a field for the path parameter "$fieldName".',
	element: routeDataClass,
	);
	}

	return encodeField(field);
	}

	String get _locationQueryParams {
	if (_ctorQueryParams.isEmpty) {
	return '';
	}

	final StringBuffer buffer = StringBuffer('queryParams: {\n');

	for (final ParameterElement param in _ctorQueryParams) {
	final String parameterName = param.name;

	final List<String> conditions = <String>[];
	if (param.hasDefaultValue) {
	if (param.type.isNullableType) {
	throw NullableDefaultValueError(param);
	}
	conditions.add('$parameterName != ${param.defaultValueCode!}');
	} else if (param.type.isNullableType) {
	conditions.add('$parameterName != null');
	}
	String line = '';
	if (conditions.isNotEmpty) {
	line = 'if (${conditions.join(' && ')}) ';
	}
	line += '${escapeDartString(parameterName.kebab)}: '
	'${_encodeFor(parameterName)},';

	buffer.writeln(line);
	}

	buffer.writeln('},');

	return buffer.toString();
	}

	late final List<ParameterElement> _ctorParams =
	_ctor.parameters.where((ParameterElement element) {
	if (_pathParams.contains(element.name)) {
	return true;
	}
	return false;
	}).toList();

	late final List<ParameterElement> _ctorQueryParams = _ctor.parameters
	.where((ParameterElement element) =>
	!_pathParams.contains(element.name) && !element.isExtraField)
	.toList();

	ConstructorElement get _ctor {
	final ConstructorElement? ctor = routeDataClass.unnamedConstructor;

	if (ctor == null) {
	throw InvalidGenerationSourceError(
	'Missing default constructor',
	element: routeDataClass,
	);
	}
	return ctor;
	}

	@override
	Iterable<String> classDeclarations() => <String>[
	_extensionDefinition,
	..._enumDeclarations(),
	];

	String get _extensionDefinition => '''
	extension $_extensionName on $_className {
	static $_className _fromState(GoRouterState state) $_fromStateConstructor

	String get location => GoRouteData.\$location($_locationArgs,$_locationQueryParams);

	void go(BuildContext context) =>
	context.go(location${_extraParam != null ? ', extra: $extraFieldName' : ''});

	Future<T?> push<T>(BuildContext context) =>
	context.push<T>(location${_extraParam != null ? ', extra: $extraFieldName' : ''});

	void pushReplacement(BuildContext context) =>
	context.pushReplacement(location${_extraParam != null ? ', extra: $extraFieldName' : ''});

	void replace(BuildContext context) =>
	context.replace(location${_extraParam != null ? ', extra: $extraFieldName' : ''});
	}
	''';

	/// Returns code representing the constant maps that contain the `enum` to
	/// [String] mapping for each referenced enum.
	Iterable<String> _enumDeclarations() {
	final Set<InterfaceType> enumParamTypes = <InterfaceType>{};

	for (final ParameterElement ctorParam in <ParameterElement>[
	..._ctorParams,
	..._ctorQueryParams,
	]) {
	DartType potentialEnumType = ctorParam.type;
	if (potentialEnumType is ParameterizedType &&
	(ctorParam.type as ParameterizedType).typeArguments.isNotEmpty) {
	potentialEnumType =
	(ctorParam.type as ParameterizedType).typeArguments.first;
	}

	if (potentialEnumType.isEnum) {
	enumParamTypes.add(potentialEnumType as InterfaceType);
	}
	}
	return enumParamTypes.map<String>(_enumMapConst);
	}

	@override
	String get routeConstructorParameters => '''
	path: ${escapeDartString(path)},
	${name != null ? 'name: ${escapeDartString(name!)},' : ''}
	''';

	@override
	String get routeDataClassName => 'GoRouteData';
	}

	/// Represents a `TypedGoRoute` annotation to the builder.
	abstract class RouteBaseConfig {
	RouteBaseConfig._({
	required this.routeDataClass,
	required this.parent,
	required this.parentNavigatorKey,
	});

	/// Creates a new [RouteBaseConfig] represented the annotation data in [reader].
	factory RouteBaseConfig.fromAnnotation(
	ConstantReader reader,
	InterfaceElement element,
	) {
	final RouteBaseConfig definition =
	RouteBaseConfig._fromAnnotation(reader, element, null);

	if (element != definition.routeDataClass) {
	throw InvalidGenerationSourceError(
	'The @TypedGoRoute annotation must have a type parameter that matches '
	'the annotated element.',
	element: element,
	);
	}

	return definition;
	}

	factory RouteBaseConfig._fromAnnotation(
	ConstantReader reader,
	InterfaceElement element,
	RouteBaseConfig? parent,
	) {
	assert(!reader.isNull, 'reader should not be null');
	final InterfaceType type = reader.objectValue.type! as InterfaceType;
	// TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
	// 5.2+ (when Flutter 3.4+ is on stable).
	// ignore: deprecated_member_use
	final bool isShellRoute = type.element.name == 'TypedShellRoute';
	final DartType typeParamType = type.typeArguments.single;
	if (typeParamType is! InterfaceType) {
	throw InvalidGenerationSourceError(
	'The type parameter on one of the @TypedGoRoute declarations could not '
	'be parsed.',
	element: element,
	);
	}

	// TODO(kevmoo): validate that this MUST be a subtype of `GoRouteData`
	// TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
	// 5.2+ (when Flutter 3.4+ is on stable).
	// ignore: deprecated_member_use
	final InterfaceElement classElement = typeParamType.element;

	final RouteBaseConfig value;
	if (isShellRoute) {
	value = ShellRouteConfig._(
	routeDataClass: classElement,
	parent: parent,
	navigatorKey: _generateNavigatorKeyGetterCode(
	classElement,
	keyName: r'$navigatorKey',
	),
	parentNavigatorKey: _generateNavigatorKeyGetterCode(
	classElement,
	keyName: r'$parentNavigatorKey',
	),
	);
	} else {
	final ConstantReader pathValue = reader.read('path');
	if (pathValue.isNull) {
	throw InvalidGenerationSourceError(
	'Missing `path` value on annotation.',
	element: element,
	);
	}

	final ConstantReader nameValue = reader.read('name');
	value = GoRouteConfig._(
	path: pathValue.stringValue,
	name: nameValue.isNull ? null : nameValue.stringValue,
	routeDataClass: classElement,
	parent: parent,
	parentNavigatorKey: _generateNavigatorKeyGetterCode(
	classElement,
	keyName: r'$parentNavigatorKey',
	),
	);
	}

	value._children.addAll(reader.read('routes').listValue.map<RouteBaseConfig>(
	(DartObject e) => RouteBaseConfig._fromAnnotation(
	ConstantReader(e), element, value)));

	return value;
	}

	final List<RouteBaseConfig> _children = <RouteBaseConfig>[];

	/// The `RouteData` class this class represents.
	final InterfaceElement routeDataClass;

	/// The parent of this route config.
	final RouteBaseConfig? parent;

	/// The parent navigator key string that is used for initialize the
	/// `RouteBase` class this config generates.
	final String? parentNavigatorKey;

	static String? _generateNavigatorKeyGetterCode(
	InterfaceElement classElement, {
	required String keyName,
	}) {
	final String? fieldDisplayName = classElement.fields
	.where((FieldElement element) {
	final DartType type = element.type;
	if (!element.isStatic \|\|
	element.name != keyName \|\|
	type is! ParameterizedType) {
	return false;
	}
	final List<DartType> typeArguments = type.typeArguments;
	if (typeArguments.length != 1) {
	return false;
	}
	final DartType typeArgument = typeArguments.single;
	if (typeArgument.getDisplayString(withNullability: false) ==
	'NavigatorState') {
	return true;
	}
	return false;
	})
	.map<String>((FieldElement e) => e.displayName)
	.firstOrNull;

	if (fieldDisplayName == null) {
	return null;
	}
	return '${classElement.name}.$fieldDisplayName';
	}

	/// Generates all of the members that correspond to `this`.
	InfoIterable generateMembers() => InfoIterable._(
	members: _generateMembers().toList(),
	routeGetterName: _routeGetterName,
	);

	Iterable<String> _generateMembers() sync* {
	final List<String> items = <String>[
	_rootDefinition(),
	];

	for (final RouteBaseConfig def in _flatten()) {
	items.addAll(def.classDeclarations());
	}

	yield* items;

	yield* items
	.expand(
	(String e) => helperNames.entries
	.where(
	(MapEntry<String, String> element) => e.contains(element.key))
	.map((MapEntry<String, String> e) => e.value),
	)
	.toSet();
	}

	/// Returns this [GoRouteConfig] and all child [GoRouteConfig] instances.
	Iterable<RouteBaseConfig> _flatten() sync* {
	yield this;
	for (final RouteBaseConfig child in _children) {
	yield* child._flatten();
	}
	}

	late final String _routeGetterName =
	r'$' + _className.substring(0, 1).toLowerCase() + _className.substring(1);

	/// Returns the `GoRoute` code for the annotated class.
	String _rootDefinition() => '''
	RouteBase get $_routeGetterName => ${_invokesRouteConstructor()};
	''';

	String get _className => routeDataClass.name;

	String get _extensionName => '\$${_className}Extension';

	String _invokesRouteConstructor() {
	final String routesBit = _children.isEmpty
	? ''
	: '''
	routes: [${_children.map((RouteBaseConfig e) => '${e._invokesRouteConstructor()},').join()}],
	''';
	final String parentNavigatorKeyParameter = parentNavigatorKey == null
	? ''
	: 'parentNavigatorKey: $parentNavigatorKey,';
	return '''
	$routeDataClassName.\$route(
	$routeConstructorParameters
	factory: $_extensionName._fromState,
	$parentNavigatorKeyParameter
	$routesBit
	)
	''';
	}

	PropertyAccessorElement? _field(String name) =>
	routeDataClass.getGetter(name);

	/// The name of `RouteData` subclass this configuration represents.
	@protected
	String get routeDataClassName;

	/// Additional constructor parameter for invoking route constructor.
	@protected
	String get routeConstructorParameters;

	/// Returns all class declarations code.
	@protected
	Iterable<String> classDeclarations();
	}

	String _enumMapConst(InterfaceType type) {
	assert(type.isEnum);

	// TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
	// 5.2+ (when Flutter 3.4+ is on stable).
	// ignore: deprecated_member_use
	final String enumName = type.element.name;

	final StringBuffer buffer = StringBuffer('const ${enumMapName(type)} = {');

	// TODO(stuartmorgan): Remove this ignore once 'analyze' can be set to
	// 5.2+ (when Flutter 3.4+ is on stable).
	// ignore: deprecated_member_use
	for (final FieldElement enumField in type.element.fields
	.where((FieldElement element) => element.isEnumConstant)) {
	buffer.writeln(
	'$enumName.${enumField.name}: ${escapeDartString(enumField.name.kebab)},',
	);
	}

	buffer.writeln('};');

	return buffer.toString();
	}

	/// [Map] from the name of a generated helper to its definition.
	const Map<String, String> helperNames = <String, String>{
	convertMapValueHelperName: _convertMapValueHelper,
	boolConverterHelperName: _boolConverterHelper,
	enumExtensionHelperName: _enumConverterHelper,
	};

	const String _convertMapValueHelper = '''
	T? $convertMapValueHelperName<T>(
	String key,
	Map<String, String> map,
	T Function(String) converter,
	) {
	final value = map[key];
	return value == null ? null : converter(value);
	}
	''';

	const String _boolConverterHelper = '''
	bool $boolConverterHelperName(String value) {
	switch (value) {
	case 'true':
	return true;
	case 'false':
	return false;
	default:
	throw UnsupportedError('Cannot convert "\$value" into a bool.');
	}
	}
	''';

	const String _enumConverterHelper = '''
	extension<T extends Enum> on Map<T, String> {
	T $enumExtensionHelperName(String value) =>
	entries.singleWhere((element) => element.value == value).key;
	}''';