Launching PHPUnit tests from a browser with Symfony2

    This post is part of the ”Symfony2 components in your own userland” series; here is a list of all the articles contained this series:

  1. Using the Symfony2 Dependency Injection Container as a standalone component
  2. Launching PHPUnit tests from a browser with Symfony2
  3. Using the Console component to write an interactive installer for Composer

Today we are going to launch interactive PHPUnit tests thanks to the Symfony2 Process component.

Premise

This article will show you how to build a script to run your unit tests from a browser and render the output to the webpage: since the aim of this series of articles is to show you how easily you can integrate Symfony2 code into your own projects, I will use nasty scripts to accomplish our requirements.

The approach

Our approach will be very basic and dummy: we are goint to execute a shell command from PHP, write each output buffers into a file and poll the file from the frontend to progressively read its content.

Into the mix

To do so, let’s create a JS-loving index.php file:

The entry point of out application
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<html>
  <body>
    <h1>PHPUnit web tests</h1>
    <a href="#" id="run">
      Run tests
    </a>
    <div id="output"></div>

    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" ></script>
    <script type="text/javascript">
      $(document).ready(function(){
        var getOutput = function(){
          $.ajax({
            url: "output.php",
            success: function(data) {
              $('#output').html(data.content);

              if (data.stop != 1) {
                getOutput();
              }
            }
          });
        };
        $('#run').click(function(){
          $.ajax({
            url: "process.php",
          });
          getOutput();
        });
      });
    </script>
  </body>
</html>

As you see, as you click on the Run tests link you will fire an event that:

The output script is really easy:

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<?php

$fileName = sys_get_temp_dir() . '/test.output.txt';
header('Content-Type: application/json');

if (file_exists($fileName)) {
  $f = file_get_contents(sys_get_temp_dir() . '/test.output.txt');

  echo json_encode(array('content' => $f));
} else {
  $f = file_get_contents(sys_get_temp_dir() . '/test.output.txt.f');

  echo json_encode(array('content' => $f, 'stop' => 1));
  unlink($f);
}

As you see, each time we call this script, it reads the content of the test.output.txt file in the temporary directory of your system: if it doesn’t find it, it reads the test.output.txt.f file1.

Enter Process

In our final step, let’s install the Process component:

composer.json
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{
    "require": {
        "php": ">=5.3.2",
        "symfony/process": "2.0.10"
    }
}
composer.json
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wget http://getcomposer.org/composer.phar

php composer.phar install

then we can create our process.php script:

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<?php

require __DIR__ . '/vendor/.composer/autoload.php';

use Symfony\Component\Process\Process;

$file = sys_get_temp_dir() . '/test.output.txt';

$handle   = fopen($file, 'w+');
$process  = new Process('phpunit -c /home/foor/bar/phpunit.xml /home/foo/bar');
$process->run(function ($type, $buffer) use($handle) {
  fwrite($handle, nl2br($buffer));
});

fclose($handle);

rename($file, $file . ".f");

As you see we are launching the test suite and, at each buffer, thanks to a lambda, we write a new chunk to the file: at the end of the process the txt file gets renamed, so the output.php script knows that it needs to notify the frontend that he’s not required to poll it anymore, adding the stop attribute to the JSON object it outputs:

fragment of output.php
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<?php

echo json_encode(array('content' => $f, 'stop' => 1));

Benefits from the Process component

I can do that crap with shell_exec() too!

There are some advantages of using Process instead of writing your own command executor: first of all, if you don’t want to take care of the subtle differences between the different platforms everything is done for you; then error handling becomes very easy since you are able to catch all the buffers:

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<?php
...

$process->run(function ($type, $buffer) {
    if ('err' === $type) {
        echo 'Something nasty happened';
            syslog(LOG_ERR, $buffer);
    } else {
        echo $buffer;
    }
});
Notes
  1. Flaw here: no error handling when the .f file is not found
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