return legacy value

packages/webview_flutter/webview_flutter_wkwebview/example/integration_test/webview_flutter_test.dart

@@ -13,6 +13,7 @@ import 'dart:io';
 // ignore: unnecessary_import
 import 'dart:typed_data';
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -1169,6 +1170,9 @@ Future<void> main() async {
 // JavaScript booleans evaluate to different string values on Android and iOS.
 // This utility method returns the string boolean value of the current platform.
 String _webviewBool(bool value) {
+  if (defaultTargetPlatform == TargetPlatform.iOS) {
+    return value ? '1' : '0';
+  }
   return value ? 'true' : 'false';
 }
 

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

@@ -314,10 +314,6 @@ class WebKitWebViewPlatformController extends WebViewPlatformController {
   @override
   Future<String> evaluateJavascript(String javascript) async {
     final Object? result = await webView.evaluateJavaScript(javascript);
-    // The legacy implementation of webview_flutter_wkwebview would convert
-    // objects to strings before returning them to Dart. This method attempts
-    // to converts Dart objects to Strings the way it is done in Objective-C
-    // to avoid breaking users expecting the same String format.
     return _asObjectiveCString(result);
   }
 
@@ -347,7 +343,7 @@ class WebKitWebViewPlatformController extends WebViewPlatformController {
         'Use `runJavascript` when expecting a null return value.',
       );
     }
-    return result.toString();
+    return _asObjectiveCString(result);
   }
 
   @override
@@ -570,6 +566,10 @@ class WebKitWebViewPlatformController extends WebViewPlatformController {
     );
   }
 
+  // The legacy implementation of webview_flutter_wkwebview would convert
+  // objects to strings before returning them to Dart. This method attempts
+  // to converts Dart objects to Strings the way it is done in Objective-C
+  // to avoid breaking users expecting the same String format.
   String _asObjectiveCString(Object? value, {bool inContainer = false}) {
     if (value == null) {
       // An NSNull inside an NSArray or NSDictionary is represented as a String

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

@@ -745,6 +745,23 @@ void main() {
         );
       });
 
+      testWidgets('runJavascriptReturningResult with bool return value',
+          (WidgetTester tester) async {
+        await buildWidget(tester);
+
+        when(mockWebView.evaluateJavaScript('runJavaScript')).thenAnswer(
+          (_) => Future<Object?>.value(false),
+        );
+        // 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.runJavascriptReturningResult('runJavaScript'),
+          completion('0'),
+        );
+      });
+
       testWidgets('runJavascript', (WidgetTester tester) async {
         await buildWidget(tester);