Chapter 8. TestCase Extensions

PHPUnit provides extensions to the standard base-class for test classes, PHPUnit_Framework_TestCase, that aid in the writing of tests for output and performance regressions.

Testing Output

Sometimes you want to assert that the execution of a method, for instance, generates an expected output (via echo or print, for example). The PHPUnit_Extensions_OutputTestCase class uses PHP's Output Buffering feature to provide the functionality that is necessary for this.

Example 8.1 shows how to subclass PHPUnit_Extensions_OutputTestCase and use its expectOutputString() method to set the expected output. If this expected output is not generated, the test will be counted as a failure.

Example 8.1: Using PHPUnit_Extensions_OutputTestCase

<?php
require_once 'PHPUnit/Extensions/OutputTestCase.php';
 
class OutputTest extends PHPUnit_Extensions_OutputTestCase
{
    public function testExpectFooActualFoo()
    {
        $this->expectOutputString('foo');
        print 'foo';
    }
 
    public function testExpectBarActualBaz()
    {
        $this->expectOutputString('bar');
        print 'baz';
    }
}
?>

phpunit OutputTest
PHPUnit 3.3.0 by Sebastian Bergmann.

.F

Time: 0 seconds

There was 1 failure:

1) testExpectBarActualBaz(OutputTest)
Failed asserting that two strings are equal.
expected string <bar>
difference      <  x>
got string      <baz>

FAILURES!
Tests: 2, Assertions: 2, Failures: 1.

Table 8.1 shows the methods provided by PHPUnit_Extensions_OutputTestCase.

Table 8.1. OutputTestCase

Method	Meaning
`void expectOutputRegex(string $regularExpression)`	Set up the expectation that the output matches a `$regularExpression`.
`void expectOutputString(string $expectedString)`	Set up the expectation that the output is equal to an `$expectedString`.
`bool setOutputCallback(callable $callback)`	Sets up a callback that is used to, for instance, normalize the actual output.

Testing Performance

You can extend your test class from PHPUnit_Extensions_PerformanceTestCase to test whether the execution of a function or method call, for instance, exceeds a specified time limit.

Example 8.2 shows how to subclass PHPUnit_Extensions_PerformanceTestCase and use its setMaxRunningTime() method to set the maximum running time for the test. If the test is not executed within this time limit, it will be counted as a failure.

Example 8.2: Using PHPUnit_Extensions_PerformanceTestCase

<?php
require_once 'PHPUnit/Extensions/PerformanceTestCase.php';
 
class PerformanceTest extends PHPUnit_Extensions_PerformanceTestCase
{
    public function testPerformance()
    {
        $this->setMaxRunningTime(2);
        sleep(1);
    }
}
?>

Table 8.2 shows the methods provided by PHPUnit_Extensions_PerformanceTestCase.

Table 8.2. PerformanceTestCase

Method	Meaning
`void setMaxRunningTime(int $maxRunningTime)`	Set the maximum running time for the test to `$maxRunningTime` (in seconds).
`integer getMaxRunningTime()`	Return the maximum running time allowed for the test.

There are two other extensions to PHPUnit_Framework_TestCase, PHPUnit_Extensions_Database_TestCase and PHPUnit_Extensions_SeleniumTestCase, that are covered in Chapter 9 and Chapter 18, respectively.