public static function assertJsonStringEqualsJsonFile($expectedFile, $actualJson, $message = '')
{
static::assertFileExists($expectedFile, $message);
$expectedJson = file_get_contents($expectedFile);
static::assertJson($expectedJson, $message);
static::assertJson($actualJson, $message);
// call constraint
$constraint = new PHPUnit_Framework_Constraint_JsonMatches($expectedJson);
static::assertThat($actualJson, $constraint, $message);
}