fix: replace fixed Task.Delay with polling in OtlpReceiverTests

Replace brittle Task.Delay(200/300) waits with a PollForOutput helper
that polls test output until the expected content appears, avoiding
flaky failures on slow CI agents. Also remove redundant
EnableTelemetryCollection override in IntegrationTestFixture since
the base class already defaults to true.

TUnit.Aspire.Tests/IntegrationTestFixture.cs

@@ -7,8 +7,6 @@ namespace TUnit.Aspire.Tests;
 /// </summary>
 public class IntegrationTestFixture : AspireFixture<Projects.TUnit_Aspire_Tests_AppHost>
 {
-    protected override bool EnableTelemetryCollection => true;
-
     protected override TimeSpan ResourceTimeout => TimeSpan.FromSeconds(120);
 
     protected override ResourceWaitBehavior WaitBehavior => ResourceWaitBehavior.AllRunning;

TUnit.Aspire.Tests/OtlpReceiverTests.cs

@@ -1,3 +1,4 @@
+using System.Diagnostics;
 using System.Net;
 using TUnit.Aspire.Telemetry;
 using TUnit.Aspire.Tests.Helpers;
@@ -90,12 +91,8 @@ public async Task Receiver_CorrelatesLogs_ToCorrectTestOutput()
 
         await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
 
-        // Allow async processing to complete
-        await Task.Delay(200);
-
         // Assert: the log should appear in this test's output
-        var output = testContext.GetStandardOutput();
-        await Assert.That(output).Contains("Hello from the SUT!");
+        var output = await PollForOutput(testContext, "Hello from the SUT!");
         await Assert.That(output).Contains("[my-api]");
         await Assert.That(output).Contains("[INFO]");
     }
@@ -122,9 +119,8 @@ public async Task Receiver_CorrelatesLogs_MultipleSeverityLevels()
         content.Headers.ContentType = new("application/x-protobuf");
 
         await client.PostAsync($"http://127.0.0.1:{receiver.Port}/v1/logs", content);
-        await Task.Delay(200);
 
-        var output = testContext.GetStandardOutput();
+        var output = await PollForOutput(testContext, "Error message");
         await Assert.That(output).Contains("[DEBUG] Debug message");
         await Assert.That(output).Contains("[INFO] Info message");
         await Assert.That(output).Contains("[ERROR] Error message");
@@ -154,8 +150,9 @@ public async Task Receiver_IgnoresLogs_WithUnknownTraceId()
         content.Headers.ContentType = new("application/x-protobuf");
 
         await client.PostAsync($"http://127.0.0.1:{receiver.Port}/v1/logs", content);
-        await Task.Delay(200);
 
+        // No matching trace ID — give a short window then verify nothing appeared
+        await Task.Delay(200);
         var output = testContext.GetStandardOutput();
         await Assert.That(output).DoesNotContain("This should not appear in test output");
     }
@@ -181,13 +178,11 @@ public async Task Receiver_CorrelatesLogs_FromMultipleResources_ToSameTest()
         content.Headers.ContentType = new("application/x-protobuf");
 
         await client.PostAsync($"http://127.0.0.1:{receiver.Port}/v1/logs", content);
-        await Task.Delay(200);
 
-        var output = testContext.GetStandardOutput();
+        var output = await PollForOutput(testContext, "Backend processing request");
         await Assert.That(output).Contains("[api-gateway]");
         await Assert.That(output).Contains("Gateway received request");
         await Assert.That(output).Contains("[backend-api]");
-        await Assert.That(output).Contains("Backend processing request");
     }
 
     [Test]
@@ -219,10 +214,8 @@ public async Task Receiver_CorrelatesLogs_ConcurrentTests_NoBleedBetweenTests()
         content.Headers.ContentType = new("application/x-protobuf");
 
         await client.PostAsync($"http://127.0.0.1:{receiver.Port}/v1/logs", content);
-        await Task.Delay(200);
 
-        var output = testContext.GetStandardOutput();
-        await Assert.That(output).Contains("My log");
+        var output = await PollForOutput(testContext, "My log");
         // The other test's log should NOT appear in this test's output
         // (it targets a non-existent TestContext, so it's silently dropped)
         await Assert.That(output).DoesNotContain("Other test's log");
@@ -253,10 +246,9 @@ public async Task Receiver_LogWithNoResourceName_FormatsWithoutPrefix()
         content.Headers.ContentType = new("application/x-protobuf");
 
         await client.PostAsync($"http://127.0.0.1:{receiver.Port}/v1/logs", content);
-        await Task.Delay(200);
 
-        var output = testContext.GetStandardOutput();
         // Should have severity but no resource prefix
+        var output = await PollForOutput(testContext, "Warning without service name");
         await Assert.That(output).Contains("[WARN] Warning without service name");
     }
 
@@ -322,9 +314,7 @@ public async Task Receiver_HandlesMultipleSequentialRequests()
             await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
         }
 
-        await Task.Delay(300);
-
-        var output = testContext.GetStandardOutput();
+        var output = await PollForOutput(testContext, "Request 4");
         for (var i = 0; i < 5; i++)
         {
             await Assert.That(output).Contains($"Request {i}");
@@ -347,4 +337,25 @@ public async Task Receiver_MalformedProtobuf_Returns200_SilentlySkips()
         // Should still return 200 (malformed protobuf is silently skipped)
         await Assert.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
     }
+
+    /// <summary>
+    /// Polls test output until it contains the expected text or a timeout is reached.
+    /// Replaces fixed <c>Task.Delay</c> waits to avoid flaky timing on slow CI agents.
+    /// </summary>
+    private static async Task<string> PollForOutput(TestContext testContext, string expected, int timeoutMs = 5000)
+    {
+        var sw = Stopwatch.StartNew();
+        while (sw.ElapsedMilliseconds < timeoutMs)
+        {
+            var output = testContext.GetStandardOutput();
+            if (output.Contains(expected))
+            {
+                return output;
+            }
+
+            await Task.Delay(50);
+        }
+
+        return testContext.GetStandardOutput();
+    }
 }