Stabilize browser readiness checks

Author: KSemenenko

tests/PrompterOne.Web.UITests.Editor/Editor/EditorToolbarDropdownPaintTests.cs

@@ -58,10 +58,11 @@ private static string BuildStepName(int scenarioIndex, string triggerTestId) =>
 
     private static async Task AssertDropdownPaintAsync(Microsoft.Playwright.IPage page, DropdownPaintScenario scenario)
     {
-        await page.GetByTestId(scenario.TriggerTestId).ClickAsync();
         var panel = page.GetByTestId(scenario.PanelTestId);
-        await Expect(panel)
-            .ToBeVisibleAsync(new() { Timeout = BrowserTestConstants.Timing.FastVisibleTimeoutMs });
+        await UiInteractionDriver.ClickAndWaitForVisibleAsync(
+            page.GetByTestId(scenario.TriggerTestId),
+            panel,
+            noWaitAfter: true);
 
         var hitTest = await page.EvaluateAsync<DropdownHitTestResult>(
             """

tests/PrompterOne.Web.UITests.Reader/Teleprompter/TeleprompterFullFlowTests.cs

@@ -157,7 +157,7 @@ private static async Task AssertCurrentActiveWordAlignedAsync(Microsoft.Playwrig
         var activeWord = page.Locator(BrowserTestConstants.Teleprompter.ActiveWordSelector);
         await Expect(activeWord).ToBeVisibleAsync(new()
         {
-            Timeout = BrowserTestConstants.Teleprompter.AlignmentTimeoutMs
+            Timeout = BrowserTestConstants.Timing.ReaderPlaybackAdvanceTimeoutMs
         });
         await AssertGuideAlignmentAsync(
             page,

tests/PrompterOne.Web.UITests/Support/EditorMonacoDriver.cs

@@ -47,11 +47,27 @@ await page.WaitForFunctionAsync(
                 """
                 (args) => {
                     const host = document.querySelector(`[data-test="${args.testId}"]`);
-                    return host?.getAttribute(args.readyAttributeName) === args.readyValue;
+                    if (!(host instanceof HTMLElement)) {
+                        return false;
+                    }
+
+                    if (host.getAttribute(args.readyAttributeName) === args.readyValue) {
+                        return true;
+                    }
+
+                    const harness = window[args.harnessGlobalName];
+                    const state = harness?.getState?.(args.testId);
+                    return state?.engine === args.editorEngineValue &&
+                        state?.languageId === args.languageId &&
+                        typeof state?.text === "string" &&
+                        state?.lineCount > 0;
                 }
                 """,
                 new
                 {
+                    editorEngineValue = EditorMonacoRuntimeContract.EditorEngineAttributeValue,
+                    harnessGlobalName = EditorMonacoRuntimeContract.BrowserHarnessGlobalName,
+                    languageId = EditorMonacoRuntimeContract.TpsLanguageId,
                     readyAttributeName = EditorMonacoRuntimeContract.EditorReadyAttributeName,
                     readyValue = "true",
                     testId = UiTestIds.Editor.SourceStage