Calling wp_die() in a REST API request should return valid JSON

[joehoyle]

See ​https://github.com/WP-API/WP-API/issues/790, whenever wp_die() is used in an API Request (which ideally it should not, but it can still happen) we should return a valid JSON response with the error.

I've been working on this, and started with an initial patch which just output the JSON and called exit, however this circumvents the rest of the API's routing etc _post_ die as script execution must stop at that point.

I ended up using PHP exceptions, which I know it not that common within WordPress, however this is the only way we can stop PHP execution of the scope that call wp_die() and still have the REST API handle the response as usual, as if the endpoint returned a WP_Error, essentially.

Attached a patch that implements this, though right now is a hack to checking if wp_die() caused the exception, this should use a WP_Die_Exception class if we actually decide to do this.

[joehoyle]

From slack:

rmccue [8:36 AM]
I think we might break things by using exceptions

try { something(); throw Exception( 'remote request 404ed' ); } catch ( Exception $e ) { /* ignore */ }
If something() calls wp_die

[danielbachhuber]

At this point, I'd much prefer we avoid wp_die() invocations REST requests. I don't think we'll be able to create a robust wp_die() handler that does what we need it to without compatibility concerns.

[rmccue]

Replying to danielbachhuber:

At this point, I'd much prefer we avoid wp_die() invocations REST requests. I don't think we'll be able to create a robust wp_die() handler that does what we need it to without compatibility concerns.

Agreed and I think adding handling here will encourage people to use it. The current behaviour (breaking the response) is probably a good thing.

Recommend close.

[rmccue]

Closing as wontfix; please don't use wp_die in your code.