[go_router_builder] Support extension types

packages/go_router_builder/CHANGELOG.md

@@ -1,6 +1,7 @@
-## NEXT
+## 3.0.2
 
 - Restricts `build` to versions less than 2.5.0.
+- Support `extension type`.
 
 ## 3.0.1
 

packages/go_router_builder/README.md

@@ -334,7 +334,7 @@ class RedirectRoute extends GoRouteData {
 
 ## Type conversions
 
-The code generator can convert simple types like `int` and `enum` to/from the
+The code generator can convert simple types like `int`, `enum`, and `extension type` to/from the
 `String` type of the underlying pathParameters:
 
 <?code-excerpt "example/lib/readme_excerpts.dart (BookKind)"?>

packages/go_router_builder/lib/src/type_helpers.dart

@@ -43,6 +43,7 @@ const List<_TypeHelper> _helpers = <_TypeHelper>[
   _TypeHelperDateTime(),
   _TypeHelperDouble(),
   _TypeHelperEnum(),
+  _TypeHelperExtensionType(),
   _TypeHelperInt(),
   _TypeHelperNum(),
   _TypeHelperString(),
@@ -263,6 +264,49 @@ class _TypeHelperEnum extends _TypeHelperWithHelper {
   bool _matchesType(DartType type) => type.isEnum;
 }
 
+/// A type helper for extension types.
+class _TypeHelperExtensionType extends _TypeHelper {
+  const _TypeHelperExtensionType();
+
+  @override
+  String _decode(
+      ParameterElement parameterElement, Set<String> pathParameters) {
+    final DartType paramType = parameterElement.type;
+    if (paramType.isNullableType && parameterElement.hasDefaultValue) {
+      throw NullableDefaultValueError(parameterElement);
+    }
+
+    final String stateValue =
+        'state.${_stateValueAccess(parameterElement, pathParameters)}';
+    final String castType;
+    if (paramType.isNullableType || parameterElement.hasDefaultValue) {
+      castType = '$paramType${paramType.isNullableType ? '' : '?'}';
+    } else {
+      castType = '$paramType';
+    }
+
+    final DartType extensionTypeErasure = paramType.extensionTypeErasure;
+    if (extensionTypeErasure.isDartCoreString) {
+      return '$stateValue as $castType';
+    }
+
+    final String parseTypeName =
+        withoutNullability(extensionTypeErasure.getDisplayString());
+    if (paramType.isNullableType || parameterElement.hasDefaultValue) {
+      return "$parseTypeName.tryParse($stateValue ?? '') as $castType";
+    } else {
+      return '$parseTypeName.parse($stateValue) as $castType';
+    }
+  }
+
+  @override
+  String _encode(String fieldName, DartType type) =>
+      '$fieldName${type.ensureNotNull}.toString()';
+
+  @override
+  bool _matchesType(DartType type) => type != type.extensionTypeErasure;
+}
+
 class _TypeHelperInt extends _TypeHelperWithHelper {
   const _TypeHelperInt();
 

packages/go_router_builder/pubspec.yaml

@@ -2,7 +2,7 @@ name: go_router_builder
 description: >-
   A builder that supports generated strongly-typed route helpers for
   package:go_router
-version: 3.0.1
+version: 3.0.2
 repository: https://github.com/flutter/packages/tree/main/packages/go_router_builder
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router_builder%22
 

packages/go_router_builder/test_inputs/extension_type_parameter.dart

@@ -0,0 +1,149 @@
+// 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 'package:go_router/go_router.dart';
+
+mixin _$ExtenstionTypeParam {}
+mixin _$ExtenstionTypeStringParam {}
+mixin _$ExtenstionTypeStringDefaultParam {}
+mixin _$ExtenstionTypeIntParam {}
+mixin _$ExtenstionTypeIntDefaultParam {}
+mixin _$ExtenstionTypeDoubleParam {}
+mixin _$ExtenstionTypeNumParam {}
+mixin _$ExtenstionTypeBoolParam {}
+mixin _$ExtenstionTypeBigIntParam {}
+mixin _$ExtenstionTypeDateTimeParam {}
+
+@TypedGoRoute<ExtenstionTypeParam>(path: '/', routes: <TypedRoute<RouteData>>[
+  TypedGoRoute<ExtenstionTypeStringParam>(path: 'string/:s'),
+  TypedGoRoute<ExtenstionTypeStringDefaultParam>(path: 'string_default/:s'),
+  TypedGoRoute<ExtenstionTypeIntParam>(path: 'int/:x'),
+  TypedGoRoute<ExtenstionTypeIntDefaultParam>(path: 'int_default/:x'),
+  TypedGoRoute<ExtenstionTypeDoubleParam>(path: 'double/:d'),
+  TypedGoRoute<ExtenstionTypeNumParam>(path: 'num/:n'),
+  TypedGoRoute<ExtenstionTypeBoolParam>(path: 'bool/:b'),
+  TypedGoRoute<ExtenstionTypeBigIntParam>(path: 'bigint/:bi'),
+  TypedGoRoute<ExtenstionTypeDateTimeParam>(path: 'datetime/:dt'),
+])
+class ExtenstionTypeParam extends GoRouteData with _$ExtenstionTypeParam {
+  ExtenstionTypeParam();
+}
+
+class ExtenstionTypeStringParam extends GoRouteData
+    with _$ExtenstionTypeStringParam {
+  ExtenstionTypeStringParam({
+    required this.s,
+    required this.requiredValue,
+    this.optionalNullableValue,
+    this.optionalDefaultValue = const StringExtensionType('default'),
+  });
+  final StringExtensionType s;
+  final StringExtensionType requiredValue;
+  final StringExtensionType? optionalNullableValue;
+  final StringExtensionType optionalDefaultValue;
+}
+
+class ExtenstionTypeStringDefaultParam extends GoRouteData
+    with _$ExtenstionTypeStringDefaultParam {
+  ExtenstionTypeStringDefaultParam({
+    this.s = const StringExtensionType('default'),
+  });
+  final StringExtensionType s;
+}
+
+class ExtenstionTypeIntParam extends GoRouteData with _$ExtenstionTypeIntParam {
+  ExtenstionTypeIntParam({
+    required this.x,
+    required this.requiredValue,
+    this.optionalNullableValue,
+    this.optionalDefaultValue = const IntExtensionType(42),
+  });
+  final IntExtensionType x;
+  final IntExtensionType requiredValue;
+  final IntExtensionType? optionalNullableValue;
+  final IntExtensionType optionalDefaultValue;
+}
+
+class ExtenstionTypeIntDefaultParam extends GoRouteData
+    with _$ExtenstionTypeIntDefaultParam {
+  ExtenstionTypeIntDefaultParam({
+    this.x = const IntExtensionType(42),
+  });
+  final IntExtensionType x;
+}
+
+class ExtenstionTypeDoubleParam extends GoRouteData
+    with _$ExtenstionTypeDoubleParam {
+  ExtenstionTypeDoubleParam({
+    required this.d,
+    required this.requiredValue,
+    this.optionalNullableValue,
+    this.optionalDefaultValue = const DoubleExtensionType(3.14),
+  });
+  final DoubleExtensionType d;
+  final DoubleExtensionType requiredValue;
+  final DoubleExtensionType? optionalNullableValue;
+  final DoubleExtensionType optionalDefaultValue;
+}
+
+class ExtenstionTypeNumParam extends GoRouteData with _$ExtenstionTypeNumParam {
+  ExtenstionTypeNumParam({
+    required this.n,
+    required this.requiredValue,
+    this.optionalNullableValue,
+    this.optionalDefaultValue = const NumExtensionType(3.14),
+  });
+  final NumExtensionType n;
+  final NumExtensionType requiredValue;
+  final NumExtensionType? optionalNullableValue;
+  final NumExtensionType optionalDefaultValue;
+}
+
+class ExtenstionTypeBoolParam extends GoRouteData
+    with _$ExtenstionTypeBoolParam {
+  ExtenstionTypeBoolParam({
+    required this.b,
+    required this.requiredValue,
+    this.optionalNullableValue,
+    this.optionalDefaultValue = const BoolExtensionType(true),
+  });
+  final BoolExtensionType b;
+  final BoolExtensionType requiredValue;
+  final BoolExtensionType? optionalNullableValue;
+  final BoolExtensionType optionalDefaultValue;
+}
+
+class ExtenstionTypeBigIntParam extends GoRouteData
+    with _$ExtenstionTypeBigIntParam {
+  ExtenstionTypeBigIntParam({
+    required this.bi,
+    required this.requiredValue,
+    this.optionalValue,
+    this.optionalNullableValue,
+  });
+  final BigIntExtensionType bi;
+  final BigIntExtensionType requiredValue;
+  final BigIntExtensionType? optionalValue;
+  final BigIntExtensionType? optionalNullableValue;
+}
+
+class ExtenstionTypeDateTimeParam extends GoRouteData
+    with _$ExtenstionTypeDateTimeParam {
+  ExtenstionTypeDateTimeParam({
+    required this.dt,
+    required this.optionalValue,
+    this.optionalNullableValue,
+  });
+  final DateTimeExtensionType dt;
+  final DateTimeExtensionType optionalValue;
+  final DateTimeExtensionType? optionalNullableValue;
+}
+
+extension type const StringExtensionType(String value) {}
+extension type const IntExtensionType(int value) {}
+extension type const DoubleExtensionType(double value) {}
+extension type const NumExtensionType(num value) {}
+extension type const BoolExtensionType(bool value) {}
+extension type const BigIntExtensionType(BigInt value) {}
+extension type const DateTimeExtensionType(DateTime value) {}