Add WP_DOING_TESTS constant, check for it in WP_Ajax_Response

[alexkingorg]

I'm writing unit tests for #21767 that need to call functions such as wp_ajax_add_tag(). These functions instantiate a WP_Ajax_Response object and send(), which sends HTTP headers and causes the unit tests to fail.

So far I can't find a way to keep the headers from being sent (anyone know how to do this?) so I'm opening this ticket as an alternate solution: introduce a WP_DOING_TESTS constant (defined in the bootstrap.php of the unit testing framework) and return out of the send() function if that constant is set to true.

Again, happy to be told there is a better way to do this, but definitely want to be able to get testing coverage of these "controller" functions.

Don't send headers if running unit tests

Matching ticket in Unit Tests trac instance:

​http://unit-tests.trac.wordpress.org/ticket/133

Have you looked at the WP_Ajax_UnitTestCase provided in the core unit tests framework? We have a number of AJAX methods (that use wp-admin/admin-ajax.php) under core tests already that use this.

I hadn't - thanks for the pointer. Will see if I can avoid needing this with those tools. Thanks!

Looks like I can use those successfully, thanks! Closing this ticket.

Some time ago I proposed another solution for this: #21282. Unfortunately it is still not implemented in core.