chore: Provide separate implementation of legacy InvokeScriptAsync behavior

src/Uno.UI/UI/Xaml/Controls/WebView/Core/CoreWebView2.cs

@@ -99,6 +99,16 @@ public partial class CoreWebView2
 			return _nativeWebView.ExecuteScriptAsync(javaScript, ct);
 		});
 
+	internal async Task<string?> InvokeScriptAsync(string script, string[]? arguments, CancellationToken ct)
+	{
+		if (_nativeWebView is null)
+		{
+			return null;
+		}
+
+		return await _nativeWebView.InvokeScriptAsync(script, arguments, ct);
+	}
+
 	internal void OnOwnerApplyTemplate()
 	{
 		_nativeWebView = GetNativeWebViewFromTemplate();

src/Uno.UI/UI/Xaml/Controls/WebView/Native/Android/NativeWebViewWrapper.Android.cs

@@ -160,8 +160,6 @@ internal class NativeWebViewWrapper : INativeWebView
 		_webView.LoadDataWithBaseURL(null, html, "text/html; charset=utf-8", "utf-8", null);
 	}
 
-	//_owner should be IAsyncOperation<string> instead of Task<string> but we use an extension method to enable the same signature in Win.
-	//IAsyncOperation is not available in Xamarin.
 	async Task<string> INativeWebView.ExecuteScriptAsync(string script, CancellationToken token)
 	{
 		TaskCompletionSource<string> tcs = new TaskCompletionSource<string>();
@@ -175,6 +173,20 @@ internal class NativeWebViewWrapper : INativeWebView
 		return await tcs.Task;
 	}
 
+	async Task<string> INativeWebView.InvokeScriptAsync(string script, string[] arguments, CancellationToken ct)
+	{
+		var argumentString = Windows.UI.Xaml.Controls.WebView.ConcatenateJavascriptArguments(arguments);
+
+		TaskCompletionSource<string> tcs = new TaskCompletionSource<string>();
+		ct.Register(() => tcs.TrySetCanceled());
+
+		_webView.EvaluateJavascript(
+			string.Format(CultureInfo.InvariantCulture, "javascript:{0}(\"{1}\");", script, argumentString),
+			new ScriptResponse(value => tcs.SetResult(value)));
+
+		return await tcs.Task;
+	}
+
 	// On Windows, the WebView ignores "about:blank" entries from its navigation history.
 	// Because Android doesn't let you modify the navigation history, 
 	// we need CanGoBack, CanGoForward, GoBack and GoForward to take the above condition into consideration.

src/Uno.UI/UI/Xaml/Controls/WebView/Native/INativeWebView.cs

@@ -25,5 +25,7 @@ internal partial interface INativeWebView
 
 	Task<string?> ExecuteScriptAsync(string script, CancellationToken token);
 
+	Task<string?> InvokeScriptAsync(string script, string[]? arguments, CancellationToken token);
+
 	void SetScrollingEnabled(bool isScrollingEnabled);
 }

src/Uno.UI/UI/Xaml/Controls/WebView/Native/iOSmacOS/UnoWKWebView.iOSmacOS.cs

@@ -644,6 +644,36 @@ public partial class UnoWKWebView : WKWebView, INativeWebView, IWKScriptMessageH
 		return await tcs.Task;
 	}
 
+	async Task<string> INativeWebView.InvokeScriptAsync(string script, string[] arguments, CancellationToken ct)
+	{
+		var argumentString = Windows.UI.Xaml.Controls.WebView.ConcatenateJavascriptArguments(arguments);
+		var javascript = string.Format(CultureInfo.InvariantCulture, "javascript:{0}(\"{1}\")", script, argumentString);
+
+		if (this.Log().IsEnabled(Uno.Foundation.Logging.LogLevel.Debug))
+		{
+			this.Log().Debug($"EvaluateJavascriptAsync: {javascript}");
+		}
+
+		var tcs = new TaskCompletionSource<string>();
+
+		using (ct.Register(() => tcs.TrySetCanceled()))
+		{
+			EvaluateJavaScript(javascript, (result, error) =>
+			{
+				if (error != null)
+				{
+					tcs.TrySetException(new InvalidOperationException($"Failed to execute javascript {error.LocalizedDescription}, {error.LocalizedFailureReason}, {error.LocalizedRecoverySuggestion}"));
+				}
+				else
+				{
+					tcs.TrySetResult(result as NSString);
+				}
+			});
+
+			return await tcs.Task;
+		}
+	}
+
 	private void ProcessNSUrlRequest(NSUrlRequest request)
 	{
 		if (request == null)

src/Uno.UI/UI/Xaml/Controls/WebView/WebView1/WebView.cs

@@ -59,16 +59,23 @@ public partial class WebView : Control, IWebView
 	public IAsyncOperation<string?> InvokeScriptAsync(string scriptName, IEnumerable<string> arguments) =>
 		AsyncOperation.FromTask(ct => InvokeScriptAsync(ct, scriptName, arguments?.ToArray()));
 
-	public async Task<string?> InvokeScriptAsync(CancellationToken ct, string script, string[]? arguments)
-	{
-		var argumentString = ConcatenateJavascriptArguments(arguments);
-		var javaScript = string.Format(CultureInfo.InvariantCulture, "{0}(\"{1}\")", script, argumentString);
-		return AdjustInvokeScriptResult(await CoreWebView2.ExecuteScriptAsync(javaScript));
-	}
+	public async Task<string?> InvokeScriptAsync(CancellationToken ct, string script, string[]? arguments) =>
+		await CoreWebView2.InvokeScriptAsync(script, arguments, ct);
 
 	public void NavigateWithHttpRequestMessage(global::System.Net.Http.HttpRequestMessage requestMessage) =>
 		CoreWebView2.NavigateWithHttpRequestMessage(requestMessage);
 
+	internal static string ConcatenateJavascriptArguments(string[]? arguments)
+	{
+		var argument = string.Empty;
+		if (arguments != null && arguments.Length > 0)
+		{
+			argument = string.Join(",", arguments);
+		}
+
+		return argument;
+	}
+
 	private void CoreWebView2_DocumentTitleChanged(CoreWebView2 sender, object args) =>
 		DocumentTitle = sender.DocumentTitle;
 
@@ -114,30 +121,4 @@ public partial class WebView : Control, IWebView
 
 	private void CoreWebView2_UnsupportedUriSchemeIdentified(CoreWebView2 sender, WebViewUnsupportedUriSchemeIdentifiedEventArgs args) =>
 		UnsupportedUriSchemeIdentified?.Invoke(this, args);
-
-	private static string? AdjustInvokeScriptResult(string result)
-	{
-		if (result is null)
-		{
-			return null;
-		}
-
-		if (result.StartsWith("\"", StringComparison.Ordinal) && result.EndsWith("\"", StringComparison.Ordinal))
-		{
-			return result.Substring(1, result.Length - 2);
-		}
-
-		return "";
-	}
-
-	private static string ConcatenateJavascriptArguments(string[]? arguments)
-	{
-		var argument = string.Empty;
-		if (arguments != null && arguments.Length > 0)
-		{
-			argument = string.Join(",", arguments);
-		}
-
-		return argument;
-	}
 }