phpunit - How to test for expected headers?

Question

I have a unit test that fails because headers are already sent. However, the header in this scenario is expected.

How do I tell PHPUnit to expect a 500 header?

I've read this question but it didn't help.

The method is wrapped inside an output buffer.

ob_start();
$foo->methodWhichSendsHeader();
ob_clean();

Answer 1

If you have xdebug installed you can use xdebug_get_headers() to get the headers. Then you can test them as needed.

$headers=xdebug_get_headers();

gets you an array which looks like...

array(
    0 => "Content-type: text/html",
    1 => ...
)

So you'll need to parse each header line to separate the header name from the value