Flaky test: "SignalRClientWorksWithLongPolling" #27156
Description
Build: https://dev.azure.com/dnceng/public/_build/results?buildId=863182&view=results
Error:
OpenQA.Selenium.BrowserAssertFailedException : Xunit.Sdk.NotEmptyException: Assert.NotEmpty() Failure
at Xunit.Assert.NotEmpty(IEnumerable collection) in C:\Dev\xunit\xunit\src\xunit.assert\Asserts\CollectionAsserts.cs:line 331
at Microsoft.AspNetCore.E2ETesting.WaitAssert.<>c__DisplayClass15_0.<Exists>b__0() in /_/src/Shared/E2ETesting/WaitAssert.cs:line 72
at Microsoft.AspNetCore.E2ETesting.WaitAssert.<>c__DisplayClass18_0`1.<WaitAssertCore>b__0(IWebDriver ) in //src/Shared/E2ETesting/WaitAssert.cs:line 109
Screen shot captured at 'F:\workspace\_work\1\s\artifacts\TestResults\Release\Microsoft.AspNetCore.Components.E2ETests\f163ef951f0844d0adfd41460fe0a86b.png'
Page content:
<head>
<meta charset="utf-8">
<title>Basic test app</title>
<base href="/subdir/">
<link href="style.css" rel="stylesheet">
<link rel="icon" href="data:,">
<link href="_content/TestContentPackage/styles.css" rel="stylesheet">
<link href="BasicTestApp.styles.css" rel="stylesheet">
</head>
<body>
<root><div id="test-selector">
Select test:
<select id="test-selector-select"><option value="none">Choose...
<option value="BasicTestApp.AfterRenderInteropComponent">After-render interop component
<option value="BasicTestApp.AuthTest.AuthRouter">Auth cases
<option value="BasicTestApp.BindCasesComponent">bind cases
<option value="BasicTestApp.ComponentRefComponent">Component ref component
<option value="BasicTestApp.ConfigurationComponent">Configuration
<option value="BasicTestApp.CounterComponent">Counter
<option value="BasicTestApp.CounterComponentWrapper">Counter wrapped in parent
<option value="BasicTestApp.DataDashComponent">data-* attribute rendering
<option value="BasicTestApp.DuplicateAttributesComponent">Duplicate attributes
<option value="BasicTestApp.ElementRefComponent">Element ref component
<option value="BasicTestApp.EventBubblingComponent">Event bubbling
<option value="BasicTestApp.EventCasesComponent">Event cases<!--!
at Microsoft.AspNetCore.E2ETesting.WaitAssert.WaitAssertCore[TResult](IWebDriver driver, Func`1 assertion, TimeSpan timeout) in /_/src/Shared/E2ETesting/WaitAssert.cs:line 139
at Microsoft.AspNetCore.E2ETesting.WaitAssert.Exists(IWebDriver driver, By finder, TimeSpan timeout) in /_/src/Shared/E2ETesting/WaitAssert.cs:line 67
at Microsoft.AspNetCore.Components.E2ETest.BasicTestAppWebDriverExtensions.WaitUntilTestSelectorReady(IWebDriver browser) in /_/src/Components/test/E2ETest/Infrastructure/WebDriverExtensions/BasicTestAppWebDriverExtensions.cs:line 24
at Microsoft.AspNetCore.Components.E2ETest.BasicTestAppWebDriverExtensions.MountTestComponent[TComponent](IWebDriver browser) in /_/src/Components/test/E2ETest/Infrastructure/WebDriverExtensions/BasicTestAppWebDriverExtensions.cs:line 18
at Microsoft.AspNetCore.Components.E2ETest.Tests.SignalRClientTest.InitializeAsyncCore() in /_/src/Components/test/E2ETest/Tests/SignalRClientTest.cs:line 38
at Microsoft.AspNetCore.E2ETesting.BrowserTestBase.InitializeAsync(String isolationContext) in /_/src/Shared/E2ETesting/BrowserTestBase.cs:line 71
----- Inner Stack Trace -----
at Microsoft.AspNetCore.E2ETesting.WaitAssert.<>c__DisplayClass15_0.<Exists>b__0() in /_/src/Shared/E2ETesting/WaitAssert.cs:line 72
at Microsoft.AspNetCore.E2ETesting.WaitAssert.<>c__DisplayClass18_0`1.<WaitAssertCore>b__0(IWebDriver _) in /_/src/Shared/E2ETesting/WaitAssert.cs:line 109