Tests JavaScript files that have querystrings attached get added right.
function testAddJsFileWithQueryString() {
$this
->drupalGet('common-test/query-string');
$query_string = variable_get('css_js_query_string', '0');
$this
->assertRaw(drupal_get_path('module', 'node') . '/node.js?' . $query_string, 'Query string was appended correctly to js.');
}