PHPUnit: Writing tests for custom assertions

Question

For our PHPUnit testing, we sometimes write custom assertions. Today I found a custom assertion that wasn't asserting quite what it ought to have been. It seems that this problem could have been avoided if I had written a unit test for the assertion itself.

The only problem I see is that I'm not quite sure how to handle writing tests for an assertion that it ought to fail, without having that lead to the test itself failing. In other words, for a test that expects a string, 'foo', I want to do something like:

public function testAssertFoo()
{
   $var = 'bar';
   $callable = array( $this, "assertFoo" );
   $this->assertTestFails( $callable, $var );
}

Of course, there is no assertTestFails assertion. But is there a clean way to do something like that?

David Harkness · Accepted Answer · 2012-09-15 23:22:01Z

2

Assuming that assertFoo uses PHPUnit's built-in assertions such as assertEquals, you can simply catch the PHPUnit_Framework_ExpectationFailedException that is thrown when the assertion fails.

function testAssertFoo() {
    try {
        $this->assertFoo('bar');
        self::fail("assertFoo should fail for 'bar'");
    }
    catch (PHPUnit_Framework_ExpectationFailedException $e) { /* test passed */ }
}

function assertFoo($value) {
    self::assertEquals('foo', $value);
}

answered Sep 15, 2012 at 23:22

David Harkness

36.6k11 gold badges119 silver badges136 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Karptonite Over a year ago

Thanks, I didn't know about the PHPUnit_Framework_ExpectationFailedException. That should do it!

Collectives™ on Stack Overflow

PHPUnit: Writing tests for custom assertions

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related