[pigeon] Adds Dart implementation of ProxyApi

packages/pigeon/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 17.0.1
 
+* [dart] Adds implementation for `@ProxyApi`.
 * Updates minimum supported SDK version to Flutter 3.13/Dart 3.1.
 
 ## 17.0.0

packages/pigeon/lib/ast.dart

@@ -4,6 +4,7 @@
 
 import 'package:collection/collection.dart' show ListEquality;
 import 'package:meta/meta.dart';
+import 'generator_tools.dart';
 import 'pigeon_lib.dart';
 
 typedef _ListEquals = bool Function(List<Object?>, List<Object?>);
@@ -177,6 +178,46 @@ class AstProxyApi extends Api {
         (ApiField field) => !field.isAttached,
       );
 
+  /// A list of AstProxyApis where each `extends` the API that follows it.
+  Iterable<AstProxyApi> get allSuperClasses => recursiveGetSuperClassApisChain(
+        this,
+      );
+
+  /// All ProxyApis this API `implements` and all the interfaces those APIs
+  /// `implements`.
+  Iterable<AstProxyApi> get apisOfInterfaces =>
+      recursiveFindAllInterfaceApis(this);
+
+  /// All methods inherited from interfaces and the interfaces of interfaces.
+  Iterable<Method> flutterMethodsFromInterfaces() sync* {
+    for (final AstProxyApi proxyApi in apisOfInterfaces) {
+      yield* proxyApi.methods;
+    }
+  }
+
+  /// A list of Flutter methods inherited from the ProxyApi that this ProxyApi
+  /// `extends`.
+  ///
+  /// This also recursively checks the ProxyApi that the super class `extends`
+  /// and so on.
+  ///
+  /// This also includes methods that super classes inherited from interfaces
+  /// with `implements`.
+  Iterable<Method> flutterMethodsFromSuperClasses() sync* {
+    for (final AstProxyApi proxyApi in allSuperClasses.toList().reversed) {
+      yield* proxyApi.flutterMethods;
+    }
+    if (superClass != null) {
+      final Set<AstProxyApi> interfaceApisFromSuperClasses =
+          recursiveFindAllInterfaceApis(
+        superClass!.associatedProxyApi!,
+      );
+      for (final AstProxyApi proxyApi in interfaceApisFromSuperClasses) {
+        yield* proxyApi.methods;
+      }
+    }
+  }
+
   @override
   String toString() {
     return '(ProxyApi name:$name methods:$methods field:$fields '