[webview_flutter_platform_interface] Add support for getting cookie (#11037)

*Replace this paragraph with a description of what this PR is changing or adding, and why. Consider including before/after screenshots.*

#10833 

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Author: khaled-0

packages/webview_flutter/webview_flutter_platform_interface/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 2.15.0
 
+* Adds support to retrieve WebView cookies. See `PlatformWebViewCookieManager.getCookies`.
 * Updates minimum supported SDK version to Flutter 3.35/Dart 3.9.
 
 ## 2.14.0

packages/webview_flutter/webview_flutter_platform_interface/lib/src/platform_webview_cookie_manager.dart

@@ -64,4 +64,12 @@ abstract class PlatformWebViewCookieManager extends PlatformInterface {
       'setCookie is not implemented on the current platform',
     );
   }
+
+  /// Returns a list of existing cookies for the specified domain from all
+  /// [WebView] instances of the application.
+  Future<List<WebViewCookie>> getCookies(Uri url) {
+    throw UnimplementedError(
+      'getCookies is not implemented on the current platform',
+    );
+  }
 }

packages/webview_flutter/webview_flutter_platform_interface/lib/src/types/webview_cookie.dart

@@ -38,4 +38,9 @@ class WebViewCookie {
   /// Its value should match "path-value" in RFC6265bis:
   /// https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis-02#section-4.1.1
   final String path;
+
+  @override
+  String toString() {
+    return 'WebViewCookie{name: $name, value: $value, domain: $domain, path: $path}';
+  }
 }

packages/webview_flutter/webview_flutter_platform_interface/pubspec.yaml

@@ -4,7 +4,7 @@ repository: https://github.com/flutter/packages/tree/main/packages/webview_flutt
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+webview_flutter%22
 # NOTE: We strongly prefer non-breaking changes, even at the expense of a
 # less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
-version: 2.14.0
+version: 2.15.0
 
 environment:
   sdk: ^3.9.0

packages/webview_flutter/webview_flutter_platform_interface/test/platform_webview_cookie_manager_test.dart

@@ -0,0 +1,125 @@
+// Copyright 2013 The Flutter Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mockito/mockito.dart';
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+import 'package:webview_flutter_platform_interface/webview_flutter_platform_interface.dart';
+
+import 'webview_platform_test.mocks.dart';
+
+void main() {
+  setUp(() {
+    WebViewPlatform.instance = MockWebViewPlatformWithMixin();
+  });
+
+  test('Cannot be implemented with `implements`', () {
+    when(
+      (WebViewPlatform.instance! as MockWebViewPlatform)
+          .createPlatformCookieManager(any),
+    ).thenReturn(ImplementsPlatformWebViewCookieManager());
+
+    expect(() {
+      PlatformWebViewCookieManager(
+        const PlatformWebViewCookieManagerCreationParams(),
+      );
+      // In versions of `package:plugin_platform_interface` prior to fixing
+      // https://github.com/flutter/flutter/issues/109339, an attempt to
+      // implement a platform interface using `implements` would sometimes throw
+      // a `NoSuchMethodError` and other times throw an `AssertionError`.  After
+      // the issue is fixed, an `AssertionError` will always be thrown.  For the
+      // purpose of this test, we don't really care what exception is thrown, so
+      // just allow any exception.
+    }, throwsA(anything));
+  });
+
+  test('Can be extended', () {
+    const params = PlatformWebViewCookieManagerCreationParams();
+    when(
+      (WebViewPlatform.instance! as MockWebViewPlatform)
+          .createPlatformCookieManager(any),
+    ).thenReturn(ExtendsPlatformWebViewCookieManager(params));
+
+    expect(PlatformWebViewCookieManager(params), isNotNull);
+  });
+
+  test('Can be mocked with `implements`', () {
+    when(
+      (WebViewPlatform.instance! as MockWebViewPlatform)
+          .createPlatformCookieManager(any),
+    ).thenReturn(MockWebViewCookieManagerDelegate());
+
+    expect(
+      PlatformWebViewCookieManager(
+        const PlatformWebViewCookieManagerCreationParams(),
+      ),
+      isNotNull,
+    );
+  });
+
+  test(
+    'Default implementation of clearCookies should throw unimplemented error',
+    () {
+      final PlatformWebViewCookieManager cookieManager =
+          ExtendsPlatformWebViewCookieManager(
+            const PlatformWebViewCookieManagerCreationParams(),
+          );
+
+      expect(() => cookieManager.clearCookies(), throwsUnimplementedError);
+    },
+  );
+
+  test(
+    'Default implementation of setCookie should throw unimplemented error',
+    () {
+      final PlatformWebViewCookieManager cookieManager =
+          ExtendsPlatformWebViewCookieManager(
+            const PlatformWebViewCookieManagerCreationParams(),
+          );
+
+      expect(
+        () => cookieManager.setCookie(
+          const WebViewCookie(name: 'foo', value: 'bar', domain: 'flutter.dev'),
+        ),
+        throwsUnimplementedError,
+      );
+    },
+  );
+
+  test(
+    'Default implementation of getCookies should throw unimplemented error',
+    () {
+      final PlatformWebViewCookieManager cookieManager =
+          ExtendsPlatformWebViewCookieManager(
+            const PlatformWebViewCookieManagerCreationParams(),
+          );
+
+      expect(
+        () => cookieManager.getCookies(Uri.parse('https://flutter.dev')),
+        throwsUnimplementedError,
+      );
+    },
+  );
+}
+
+class MockWebViewPlatformWithMixin extends MockWebViewPlatform
+    with
+        // ignore: prefer_mixin
+        MockPlatformInterfaceMixin {}
+
+class ImplementsPlatformWebViewCookieManager
+    implements PlatformWebViewCookieManager {
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+class MockWebViewCookieManagerDelegate extends Mock
+    with
+        // ignore: prefer_mixin
+        MockPlatformInterfaceMixin
+    implements PlatformWebViewCookieManager {}
+
+class ExtendsPlatformWebViewCookieManager extends PlatformWebViewCookieManager {
+  ExtendsPlatformWebViewCookieManager(super.params) : super.implementation();
+}