How to force fail a test in C# with MSTest

Question

I am trying to port some of my WebDriver tests from JAVA to C#. What I'm stuck on is the situation when the driver cannot find some element on the page, in JAVA I do :

if (second >= 10) fail("timeout - " + list);

so if something takes more than 10 seconds the test fails with the timeout message. I tried a similar approach in C# with

if (sec >= 10) Debug.Fail("timeout : " + vList);

but this actually did not fail the test, but gave me an option to do so with the exception message box. That was a no no, I need my automatic test to fail outright on its own. Then I tried

if (sec >= 10) Assert.Fail("timeout : " + vList);

but this is throwing an unhandled exception error. Should I enclose the Assert.Fail in try/catch block? Or should I use something completely different to fail the test?

I am using MSTest, as mentioned in the topic.

EDIT: The exact message is :

AssertFailedException was unhandled by user code. Assert.Fail failed. timeout : someField.

on

Assert.Fail("timeout : " + vList);

This is the expected behavior. All `Assert` methods are throwing an `AssertFailedException` if they fail so you can see that the test was failed. If you catch the exception the test will pass. — chaliasos, Jun 14 '12 at 14:30
Hmm, ok. The problem is that the test throws the unhandled exception and pauses, with the unhandled exception message displayed. I would like it to fail all right but stop afterwards, reporting fail. — tom, Jun 15 '12 at 07:35
Perhaps because you are debugging your test. If you run it will fail and the error will be displayed in the `Test Results` window. — chaliasos, Jun 15 '12 at 08:12

score 6 · Accepted Answer · answered Jun 15 '12 at 07:59

6

I think you're seeing that behaviour because you've got the debugger attached to the running test - Assert.Fail throws AssertFailedException, your debugger sees the exception and breaks - and you don't get test results.

On the Debug menu, go into Exceptions, find AssertFailedException (or create an entry for it if it's not there) and make sure break on throw is turned off for that exception type.

Alternatively, run your tests without the debugger attached.

answered Jun 15 '12 at 07:59

tomfanning

9,552
4
50
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DIdin't even know you can start with/without debugging. I added the exception to the exceptions list and that solved the problem. Thanks! – tom Jun 15 '12 at 08:29
Handy hint. `Ctrl-R then T` runs tests without the debugger attached, `Ctrl-R then Ctrl-T` runs tests *with* the debugger attached. – tomfanning Jun 15 '12 at 08:31

score 1 · Answer 2 · answered Jun 14 '12 at 13:32

Assert.Fail should be what you want to "force" a failure. Internally, it will throw an AssertFailedException. Something else could be going on if this doesn't work...

a quick dotPeek shows this gets called:

internal static void HandleFail(string assertionName, string message, params object[] parameters)
{
  string str = string.Empty;
  if (!string.IsNullOrEmpty(message))
    str = parameters != null ? string.Format((IFormatProvider) CultureInfo.CurrentCulture, Assert.ReplaceNulls((object) message), parameters) : Assert.ReplaceNulls((object) message);
  if (Assert.AssertionFailure != null)
    Assert.AssertionFailure((object) null, EventArgs.Empty);
  throw new AssertFailedException(FrameworkMessages.AssertionFailed((object) assertionName, (object) str));
}

score 0 · Answer 3 · answered Jun 14 '12 at 13:38

0

You must use appropriate syntax for mstest

[TestMethod]
public void IsSecondsGreaterOrEqualThanTen()
{
    Assert.IsTrue(second >= 10);
}

answered Jun 14 '12 at 13:38

Hamlet Hakobyan

32,965
6
52
68

He wants the opposite. `Assert.IsTrue(second < 10);` or `Assert.IsFalse(second >= 10);` – chaliasos Jun 14 '12 at 14:02

How to force fail a test in C# with MSTest

3 Answers3