[release/11.0.1xx-preview7] De-flake DragEvents UI test assertions

src/Controls/tests/TestCases.Shared.Tests/Tests/DragAndDropUITests.cs

@@ -33,50 +33,24 @@ public void DragEvents()
 			App.WaitForElement("LabelDragElement");
 			App.DragAndDrop("LabelDragElement", "DragTarget");
 
-			App.WaitForElement("DragStartEventsLabel");
-			var textAfterDragStart = App.FindElement("DragStartEventsLabel").GetText();
-
-			if (string.IsNullOrEmpty(textAfterDragStart))
-			{
-				Assert.Fail("Text was expected: Drag start event");
-			}
-			else
-			{
-				Assert.That(textAfterDragStart, Is.EqualTo("DragStarting"));
-			}
-
-			App.WaitForElement("DragOverEventsLabel");
-			var textAfterDragOver = App.FindElement("DragOverEventsLabel").GetText();
-			if (string.IsNullOrEmpty(textAfterDragOver))
-			{
-				Assert.Fail("Text was expected: Drag over event");
-			}
-			else
-			{
-				Assert.That(textAfterDragOver, Is.EqualTo("DragOver"));
-			}
-
-			App.WaitForElement("DragCompletedEventsLabel");
-			var textAfterDragComplete = App.FindElement("DragCompletedEventsLabel").GetText();
-			if (string.IsNullOrEmpty(textAfterDragComplete))
-			{
-				Assert.Fail("Text was expected: Drag complete event");
-			}
-			else
-			{
-				Assert.That(textAfterDragComplete, Is.EqualTo("DropCompleted"));
-			}
+			AssertEventText("DragStartEventsLabel", "DragStarting");
+			AssertEventText("DragOverEventsLabel", "DragOver");
+			AssertEventText("DragCompletedEventsLabel", "DropCompleted");
+			AssertEventText("DropEventsLabel", "Drop");
+		}
 
-			App.WaitForElement("DropEventsLabel");
-			var textAfterDrop = App.FindElement("DropEventsLabel").GetText();
-			if (string.IsNullOrEmpty(textAfterDrop))
-			{
-				Assert.Fail("Text was expected: Drop event");
-			}
-			else
-			{
-				Assert.That(textAfterDrop, Is.EqualTo("Drop"));
-			}
+		void AssertEventText(string automationId, string expectedText)
+		{
+			// Wait for the label's text to become EXACTLY the expected value. A substring wait is
+			// unreliable here because each label's placeholder (e.g. "DragOverEvents: ") already
+			// contains the expected event name (e.g. "DragOver"), so a Contains-based wait would pass
+			// immediately on the placeholder. WaitForTextEqualToElement polls until the text matches
+			// exactly, so the Assert below fails only on a genuine timeout; no separate GetText re-read
+			// is needed (it would only re-open a window for transient Appium flakiness).
+			Assert.That(
+				App.WaitForTextEqualToElement(automationId, expectedText),
+				Is.True,
+				$"Timed out waiting for {automationId} to become '{expectedText}'.");
 		}
 
 		[Test]
@@ -94,7 +68,7 @@ public void DragAndDropBetweenLayouts()
 			App.WaitForElement("Green");
 			App.DragAndDrop("Red", "Green");
 
-			App.WaitForElement("DragStartEventsLabel");
+			App.WaitForTextEqualToElement("DragStartEventsLabel", "DragStarting");
 			var textAfterDragStart = App.FindElement("DragStartEventsLabel").GetText();
 
 			if (string.IsNullOrEmpty(textAfterDragStart))
@@ -106,7 +80,7 @@ public void DragAndDropBetweenLayouts()
 				Assert.That(textAfterDragStart, Is.EqualTo("DragStarting"));
 			}
 
-			App.WaitForElement("DragOverEventsLabel");
+			App.WaitForTextEqualToElement("DragOverEventsLabel", "DragOver");
 			var textAfterDragOver = App.FindElement("DragOverEventsLabel").GetText();
 			if (string.IsNullOrEmpty(textAfterDragOver))
 			{
@@ -117,7 +91,7 @@ public void DragAndDropBetweenLayouts()
 				Assert.That(textAfterDragOver, Is.EqualTo("DragOver"));
 			}
 
-			App.WaitForElement("DragCompletedEventsLabel");
+			App.WaitForTextEqualToElement("DragCompletedEventsLabel", "DropCompleted");
 			var textAfterDragComplete = App.FindElement("DragCompletedEventsLabel").GetText();
 			if (string.IsNullOrEmpty(textAfterDragComplete))
 			{
@@ -139,7 +113,7 @@ public void DragAndDropBetweenLayouts()
 				Assert.That(rainbowColorText, Is.EqualTo("RainbowColorsAdd:Red"));
 			}
 
-			App.WaitForElement("DropEventsLabel");
+			App.WaitForTextEqualToElement("DropEventsLabel", "Drop");
 			var textAfterDrop = App.FindElement("DropEventsLabel").GetText();
 			if (string.IsNullOrEmpty(textAfterDrop))
 			{

src/TestUtils/src/UITest.Appium/HelperExtensions.cs

@@ -1054,30 +1054,54 @@ public static void WaitForNoElement(
 		}
 
 		public static bool WaitForTextToBePresentInElement(this IApp app, string automationId, string text, TimeSpan? timeout = null)
+			=> app.WaitForText(automationId, text, s => s.Contains(text, StringComparison.OrdinalIgnoreCase), timeout);
+
+		/// <summary>
+		/// Waits until the element's text is exactly equal to <paramref name="text"/> (ordinal), rather
+		/// than merely containing it. Use this when the element's placeholder/initial text already
+		/// contains the expected value as a substring, which would make a Contains-based wait pass
+		/// prematurely on the placeholder.
+		/// </summary>
+		public static bool WaitForTextEqualToElement(this IApp app, string automationId, string text, TimeSpan? timeout = null)
+			=> app.WaitForText(automationId, text, s => string.Equals(s, text, StringComparison.Ordinal), timeout);
+
+		/// <summary>
+		/// Shared polling loop for the text-wait helpers. Repeatedly reads the element's text and
+		/// returns <see langword="true"/> as soon as <paramref name="matches"/> is satisfied. On
+		/// timeout it logs the last observed text (and the expected value) so a stalled or
+		/// placeholder-stuck label is distinguishable from a text-read failure, then returns
+		/// <see langword="false"/>.
+		/// </summary>
+		static bool WaitForText(this IApp app, string automationId, string expected, Func<string, bool> matches, TimeSpan? timeout)
 		{
 			timeout ??= DefaultTimeout;
 			TimeSpan retryFrequency = TimeSpan.FromMilliseconds(500);
 
 			DateTime start = DateTime.Now;
+			string? lastObservedText = null;
 
 			while (true)
 			{
 				var element = app.FindElements(automationId).FirstOrDefault();
 
-				if (element is not null && element.TryGetText(out var s) && s.Contains(text, StringComparison.OrdinalIgnoreCase))
+				if (element is not null && element.TryGetText(out var s))
 				{
-					return true;
+					lastObservedText = s;
+					if (matches(s))
+					{
+						return true;
+					}
 				}
 
 				long elapsed = DateTime.Now.Subtract(start).Ticks;
 				if (elapsed >= timeout.Value.Ticks)
 				{
-					Debug.WriteLine($">>>>> {elapsed} ticks elapsed, timeout value is {timeout.Value.Ticks}");
+					Debug.WriteLine($">>>>> {elapsed} ticks elapsed, timeout value is {timeout.Value.Ticks}; last observed text for '{automationId}' was '{lastObservedText ?? "<unavailable>"}', expected '{expected}'");
 
 					return false;
 				}
 
-				Task.Delay(retryFrequency.Milliseconds).Wait();
+				Task.Delay(retryFrequency).Wait();
 			}
 		}