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Testing for PHP

Wed, 08/15/2007 - 16:47 — stuart
PHP does not embed unit testing as well into development practice as with other languages like Java and Perl. Even with PHP, however, it is a good habit to get into. With unit testing and integration testing on hand, it is easier to track a project and monitor for inconsistencies between the different parts of the development work. Fortunately, there is an excellent testing framework for PHP: SimpleTest, available at http://simpletest.org/. It has more features in it than you could throw a stick at, and it works well and robustly. Meet-O-Matic now uses this as a key part of its development process, but other, larger, systems (such as Moodle) do too. However, for Meet-O-Matic, I wanted a rather better report than was available in the basic version. For example, I wanted to detect all syntax errors, not just crashing out when one was detected. And secondly, I wanted to have a set of tests, each classified in some way. To achieve all this, a few tweaks were needed. First of all, I subclassed SimpleReporter as follows:

<?php
require_once('simpletest/simpletest.php');

class StringReporter extends SimpleReporter {

    var $result = "";
    var $_character_set = 'ISO-8859-1';

    function getBlock() {
        return $this->result;
    }

    function paintHeader() {
        $this->add("<h3>Testing module: $test_name</h3>\n");
    }

    function add($string) {
        $this->result .= $string;
    }

    function paintFooter() {
        $style = ($this->getFailCount() + () > 0 ? "failblock" : "passblock");
        $this->add("<div class=\"$style\">");
        $this->add($this->getTestCaseProgress() . "/" . $this->getTestCaseCount());
        $this->add(" test cases complete:\n");
        $this->add("<strong>" . $this->getPassCount() . "</strong> passes, ");
        $this->add("<strong>" . $this->getFailCount() . "</strong> fails and ");
        $this->add("<strong>" . $this->getExceptionCount() . "</strong> exceptions.");
        $this->add("</div>\n");
    }

    function paintStart($test_name, $size) {
        parent::paintStart($test_name, $size);
    }

    function paintEnd($test_name, $size) {
        parent::paintEnd($test_name, $size);
    }

    function paintPass($message) {
        parent::paintPass($message);
    }

    function paintFail($message) {
        parent::paintFail($message);
        $this->add("<span class=\"fail\">Fail</span>: ");
        $breadcrumb = $this->getTestList();
        array_shift($breadcrumb);
        $this->add(implode(" -> ", $breadcrumb));
        $this->add(" -> " . $this->_htmlEntities($message) . "<br />\n");
    }

    function paintError($message) {
        parent::paintError($message);
        $this->add("<span class=\"fail\">Exception</span>: ");
        $breadcrumb = $this->getTestList();
        array_shift($breadcrumb);
        $this->add(implode(" -> ", $breadcrumb));
        $this->add(" -> <strong>" . $this->_htmlEntities($message) . "</strong><br />\n");
    }

    function paintSkip($message) {
        parent::paintSkip($message);
        $this->add("<span class=\"pass\">Skipped</span>: ");
        $breadcrumb = $this->getTestList();
        array_shift($breadcrumb);
        $this->add(implode(" -> ", $breadcrumb));
        $this->add(" -> " . $this->_htmlEntities($message) . "<br />\n");
    }

    function _htmlEntities($message) {
        return htmlentities($message, ENT_COMPAT, $this->_character_set);
    }
}
?>

All this does is generate a string block of HTML rather than a file - because of this we can now glue several of these together into a single page display. The next page runs the tests in all files ending _test.php, and then combines the results into a single page. It assumes that the class in each file is called TestOf..., where the ... is filled from the name of the file (minus _test.php). Most of the rest is styling.

<?php
require_once('simpletest/unit_tester.php');
require_once('StringReporter.php');

$tests = glob("*_test.php");

?><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
    "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>All tests&lt;/title>
<meta http-equiv="Content-Type" content="text/html">
<style type="text/css">
body { font-family: Verdana, sans-serif; font-size: 1.8ex }
.failblock { padding: 8px; margin-top: 1em; background-color: red; color: white; }
.passblock { padding: 8px; margin-top: 1em; background-color: green; color: white; }
.fail { background-color: inherit; color: red; }
.pass { background-color: inherit; color: green; }
pre { background-color: lightgray; color: inherit; }
</style>
</head>
<body>
<?php
foreach ($tests as $test) {
    $name = preg_replace("/_test.php$/", "", );
    require($test);
    
    $suite = &new TestSuite($name);
    $instance = eval("return new TestOf$name();");
    $suite->addTestCase($instance);

    $reporter = new StringReporter();
    $suite->run($reporter);
    echo $reporter->getBlock();
}
?>
</body>
</html>

OK, so this is a bit of a hack, but it does work, and the results are a bit better broken down than having a large single block of tests (which is done, for example, by Moodle). Even so, SimpleTest is great: it does everything you are likely to need, although you may well want to subclass it from time to time.
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