pTest: PHP Unit Tester in 9 Lines Of Code

I was recently working on a command line PHP tool, and didn’t have easy access to our normal PHP unit testing framework built around SimpleTest. After a few lines of non-test-driven-development, I started to freak out a bit – I guess I’ve fallen for the view that if code doesn’t have tests, it’s broken.

I didn’t need support for mock objects or complicated assertions – just a bare basic assertTrue() would do the trick. So, I present “pTest”, in 9 lines of code:


/**
 * pTest - PHP Unit Tester
 * @param mixed $test Condition to test, evaluated as boolean
 * @param string $message Descriptive message to output upon test
 */
function assertTrue($test, $message)
{
	static $count;
	if (!isset($count)) $count = array('pass'=>0, 'fail'=>0, 'total'=>0);

	$mode = $test ? 'pass' : 'fail';
	printf("%s: %s (%d of %d tests run so far have %sed)n",
		strtoupper($mode), $message, ++$count[$mode], ++$count['total'], $mode);
}

Here’s a few contrived test cases to demonstrate:


assertTrue(1 + 1 == 2, 'one plus one should equal two');
assertTrue(false, 'false should be true (this one will fail)');
assertTrue(!false, 'false should be false');

And the sample output:


PASS: one plus one should equal two (1 of 1 tests run so far have passed)
FAIL: false should be true (this one will fail) (1 of 2 tests run so far have failed)
PASS: false should be false (2 of 3 tests run so far have passed)

If you’re viewing the output in a web browser, you could easily wrap each output message in a <p> tag. Or if you’re using a non-broken browser you could serve the response with header('Content-Type: text/plain');.

Obviously this isn’t to be taken too seriously. Then again, I found it extremely useful to drop into the few command line scripts I was working on.

Another use I can see for such a simple testing function is introducing the uninitiated into the world of unit testing. I know that before I got into it, the biggest barrier was the complexity of the frameworks. Perhaps pTest will give beginners a starting point, from which they can move onto more feature-rich frameworks like PHPUnit or SimpleTest once they outgrow the humble assertTrue().

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  • http://www.authelo.com z0s0

    Interestingly, PHP actually has an assertion tester built-in:

    http://php.net/assert

  • Paul Annesley

    Good point.. although configuring it to result in output similar to assertTrue() (without making any assumptions about PHP’s global configuration) probably uses more lines of code ;)

    With a bit of work it can certainly be set up nicely – with added benefits like line number reporting, and output of the evaled assertion code.

    But I think the simplicity and self contained nature of pTest probably makes it less daunting to beginners to PHP and unit testing.

  • http://www.authelo.com z0s0

    Yeah… reckon it must be one of PHP’s least used builtins.

  • deathshadow

    Good lord, people write whole units for this stuff? You know, after three decades of doing this ****, I am still amazed people ever need to waste time on this level of internal reporting.

    Unit tester – took me a while just to figure out you meant result tracking… is that the new name for a four decade old method of code auditing?

  • http://shiflett.org/ shiflett

    You might want to check out TAP, the Test Anything Protocol:

    http://testanything.org/

    If you’re going to write a simple library like this, making it TAP-compliant means your output is going to be consumable by a number of mature testing tools.

    There’s a PHP library that comes bundled with Apache-Test that outputs TAP and is almost as simple as yours:

    http://shiflett.org/code/test-more.php

  • Christopher Thompson

    I wrote a small unit tester as part of a forum discussion a while back that I called TinyTest. Although it is 50 lines, not 9, it provides assertTrue(), assertFalse(), pass() and fail() plus standard green/red output of the results. The original ideas was to have a unit tester small enough that you could supply it with posted code and tests.

    
    class UnitTester {
            var $_passes = 0;
            var $_fails = 0;
            var $_test_stack = array();
            var $_trace_pos = 0;
            var $output = '';
           
            function assertTrue($result, $pos=0) {
                    if ($result) {
                            $this->pass();
                    } else {
                            $this->_trace_pos = $pos + 1;
                            $this->fail();
                    }
            }
    
            function assertFalse($result, $pos=0) {
                    if ($result) {
                            $this->_trace_pos = $pos + 1;
                            $this->fail();
                    } else {
                            $this->pass();
                    }
            }
    
            function pass() {
                    ++$this->_passes;
            }
    
            function fail() {
                    ++$this->_fails;
                    $test_data = debug_backtrace();
                    $this->_test_stack[] = $test_data[$this->_trace_pos];
                    $this->_trace_pos = 0;
            }
    
            var $passed_heading_style = 'color: white; background-color: green; margin-top: 2; padding: 4 4 4 4;';
            var $failed_heading_style = 'color: white; background-color: red; margin-top: 2; padding: 4 4 4 4;';
            var $failed_test_style = 'color: white; background-color: red; margin-top: 2; padding-left: 4;';
    
            function __destruct() {
                    if ($this->_fails > 0) {
                            $output = '<div style="' . $this->failed_heading_style . '">Failed ' . $this->_fails . ' of ' . ($this->_fails + $this->_passes) . ' tests. </div>';
                            $n = 1;
                            foreach ($this->_test_stack as $this_data) {
                                    $message = $n++ . ". Failed: {$this_data['function']} on line {$this_data['line']} of file {$this_data['file']}. ";
                                    $output .= '<div style="' . $this->failed_test_style . '">' . $message . '</div>';
                            }
                    } else {
                            $output = '<div style="' . $this->passed_heading_style . '">Passed ' .$this->_passes . ' tests.</div>';
                    }
                echo $output;
            }
    
    }