Testing form inputs in PHPUnit

Question

What's the best way to test $_GET and $_POST inputs in PHPUnit?

I have a class that sanitises input and want to check that it works correctly when processing bogus data. Is there an easy way to set up the form variables in PHPUnit or should I just pass off the validation to a secondary class/functions that are fed the form variables so test them indirectly?

Answer 1

Take a look at the idea of Dependency injection. In a nutshell you should feed your code what it needs as opposed to it getting the data it needs... Here's an example:

example without Dependency Injection

function sanitize1() {
  foreach($_POST as $k => $v) {
    // code to sanitize $v
  }
}

sanitize1();

example with Dependency Injection

function sanitize2(array &$formData) {
  foreach($formData as $k => $v) {
    // code to sanitize $v
  }
}

sanitize2($_POST);

See the difference? In your PHPUnit test you can pass sanitize2() an associative array of your choice; you've injected the dependency. Whereas sanitize1() is coupled with $_POST. $_POST and $_GET are assoc arrays anyways so in your production code you can pass $_GET or $_POST to your function but in your unit tests you'd hard code some expected data.

Unit test example:

function testSanitize() {
  $fakeFormData = array ('bio' => 'hi i\'m arin', 'location' => 'San Francisco');
  sanitize($fakeFormData);
  // assert something
}