[webview_flutter_wkwebview] Fixes bug where an NSError not an `NSEr…

…rorData` was returned (flutter#5973)

packages/webview_flutter/webview_flutter_wkwebview/example/ios/RunnerTests/FWFWebViewHostApiTests.m

@@ -351,4 +351,41 @@ - (void)testEvaluateJavaScript {
  XCTAssertEqualObjects(returnValue, @"result");
  XCTAssertNil(returnError);
 }
+
+- (void)testEvaluateJavaScriptReturnsNSErrorData {
+ FWFWebView *mockWebView = OCMClassMock([FWFWebView class]);
+
+ OCMStub([mockWebView
+ evaluateJavaScript:@"runJavaScript"
+ completionHandler:([OCMArg invokeBlockWithArgs:[NSNull null],
+ [NSError errorWithDomain:@"errorDomain"
+ code:0
+ userInfo:@{
+ NSLocalizedDescriptionKey :
+ @"description"
+ }],
+ nil])]);
+
+ FWFInstanceManager *instanceManager = [[FWFInstanceManager alloc] init];
+ [instanceManager addDartCreatedInstance:mockWebView withIdentifier:0];
+
+ FWFWebViewHostApiImpl *hostAPI =
+ [[FWFWebViewHostApiImpl alloc] initWithInstanceManager:instanceManager];
+
+ NSString __block *returnValue;
+ FlutterError __block *returnError;
+ [hostAPI evaluateJavaScriptForWebViewWithIdentifier:@0
+ javaScriptString:@"runJavaScript"
+ completion:^(id result, FlutterError *error) {
+ returnValue = result;
+ returnError = error;
+ }];
+
+ XCTAssertNil(returnValue);
+ FWFNSErrorData *errorData = returnError.details;
+ XCTAssertTrue([errorData isKindOfClass:[FWFNSErrorData class]]);
+ XCTAssertEqualObjects(errorData.code, @0);
+ XCTAssertEqualObjects(errorData.domain, @"errorDomain");
+ XCTAssertEqualObjects(errorData.localizedDescription, @"description");
+}
 @end

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FWFWebViewHostApi.m

@@ -141,7 +141,7 @@ - (void)evaluateJavaScriptForWebViewWithIdentifier:(nonnull NSNumber *)identifie
  if (!result || [result isKindOfClass:[NSString class]] ||
  [result isKindOfClass:[NSNumber class]]) {
  returnValue = result;
- } else {
+ } else if (![result isKindOfClass:[NSNull class]]) {
  NSString *className = NSStringFromClass([result class]);
  NSLog(@"Return type of evaluateJavaScript is not directly supported: %@. Returned "
  @"description of value.",
@@ -151,7 +151,7 @@ - (void)evaluateJavaScriptForWebViewWithIdentifier:(nonnull NSNumber *)identifie
  } else {
  flutterError = [FlutterError errorWithCode:@"FWFEvaluateJavaScriptError"
  message:@"Failed evaluating JavaScript."
- details:error];
+ details:FWFNSErrorDataFromNSError(error)];
  }
 
  completion(returnValue, flutterError);

packages/webview_flutter/webview_flutter_wkwebview/lib/src/web_kit/web_kit_api_impls.dart

@@ -908,11 +908,25 @@ class WKWebViewHostApiImpl extends WKWebViewHostApi {
  Future<Object?> evaluateJavaScriptForInstances(
  WKWebView instance,
  String javaScriptString,
- ) {
- return evaluateJavaScript(
- instanceManager.getIdentifier(instance)!,
- javaScriptString,
- );
+ ) async {
+ try {
+ final Object? result = await evaluateJavaScript(
+ instanceManager.getIdentifier(instance)!,
+ javaScriptString,
+ );
+ return result;
+ } on PlatformException catch (exception) {
+ if (exception.details is! NSErrorData) {
+ rethrow;
+ }
+
+ throw PlatformException(
+ code: exception.code,
+ message: exception.message,
+ stacktrace: exception.stacktrace,
+ details: (exception.details as NSErrorData).toNSError(),
+ );
+ }
  }
 
  /// Calls [setNavigationDelegate] with the ids of the provided object instances.

packages/webview_flutter/webview_flutter_wkwebview/lib/src/web_kit_webview_widget.dart

@@ -573,6 +573,10 @@ class WebKitWebViewPlatformController extends WebViewPlatformController {
  return '"<null>"';
  }
  return '(null)';
+ } else if (value is bool) {
+ return value ? '1' : '0';
+ } else if (value is double && value.truncate() == value) {
+ return value.truncate().toString();
  } else if (value is List) {
  final List<String> stringValues = <String>[];
  for (final Object? listValue in value) {

packages/webview_flutter/webview_flutter_wkwebview/test/src/web_kit/web_kit_test.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/annotations.dart';
 import 'package:mockito/mockito.dart';
@@ -815,6 +816,30 @@ void main() {
  .thenAnswer((_) => Future<String>.value('stopstop'));
  expect(webView.evaluateJavaScript('gogo'), completion('stopstop'));
  });
+
+ test('evaluateJavaScript returns NSError', () {
+ when(mockPlatformHostApi.evaluateJavaScript(webViewInstanceId, 'gogo'))
+ .thenThrow(
+ PlatformException(
+ code: '',
+ details: NSErrorData(
+ code: 0,
+ domain: 'domain',
+ localizedDescription: 'desc',
+ ),
+ ),
+ );
+ expect(
+ webView.evaluateJavaScript('gogo'),
+ throwsA(
+ isA<PlatformException>().having(
+ (PlatformException exception) => exception.details,
+ 'details',
+ isA<NSError>(),
+ ),
+ ),
+ );
+ });
  });
 
  group('WKUIDelegate', () {

packages/webview_flutter/webview_flutter_wkwebview/test/src/web_kit_webview_widget_test.dart

@@ -634,6 +634,42 @@ void main() {
  );
  });
 
+ testWidgets('evaluateJavascript with bool return value',
+ (WidgetTester tester) async {
+ await buildWidget(tester);
+
+ when(mockWebView.evaluateJavaScript('runJavaScript')).thenAnswer(
+ (_) => Future<Object?>.value(true),
+ );
+ // The legacy implementation of webview_flutter_wkwebview would convert
+ // objects to strings before returning them to Dart. This verifies bool
+ // is represented the way it is in Objective-C.
+ // `NSNumber.description` converts bool values to a 1 or 0.
+ expect(
+ testController.evaluateJavascript('runJavaScript'),
+ completion('1'),
+ );
+ });
+
+ testWidgets('evaluateJavascript with double return value',
+ (WidgetTester tester) async {
+ await buildWidget(tester);
+
+ when(mockWebView.evaluateJavaScript('runJavaScript')).thenAnswer(
+ (_) => Future<Object?>.value(1.0),
+ );
+ // The legacy implementation of webview_flutter_wkwebview would convert
+ // objects to strings before returning them to Dart. This verifies
+ // double is represented the way it is in Objective-C. If a double
+ // doesn't contain any decimal values, it gets truncated to an int.
+ // This should be happenning because NSNumber convertes float values
+ // with no decimals to an int when using `NSNumber.description`.
+ expect(
+ testController.evaluateJavascript('runJavaScript'),
+ completion('1'),
+ );
+ });
+
  testWidgets('evaluateJavascript with list return value',
  (WidgetTester tester) async {
  await buildWidget(tester);