Scripts: Assign api-fetch nonce with corrected rest_nonce

[aduth]

Previously: #45113

Related: ​https://github.com/WordPress/gutenberg/pull/13451

The above package change for @wordpress/api-fetch will have the affect both that api-fetch will not internally listen for hearbeat.tick actions, but also that the nonce used for requests can be assignable on the created middleware.

Thus, core could use this new mechanism to assign the nonce via an inline script on heartbeat tick, using the corrected rest_nonce property on a heartbeat response which had temporarily been patched in r43939 for the sake of api-fetch compatibility.

The release schedule of @wordpress/api-fetch would be such that it's expected this would need to be fixed in time for WordPress 5.2.

[aduth]

Add missing semi-colon

[adamsilverstein]

@aduth Looks good to me!

It would be good to have the expected nonce behavior covered in a test, do you know if we have that already?

[aduth]

It would be good to have the expected nonce behavior covered in a test, do you know if we have that already?

I'm not aware of any. Is there precedent for how something like this would be tested? I could imagine one which tests that wp-hooks becomes added as a dependency of wp-api-fetch, but the main behavior here occurs in the browser in response to the heartbeat tick. Is that something which could be done in the QUnit tests? In Gutenberg, I could maybe imagine an end-to-end test forcing wp.heartbeat.connectNow and asserting in one way or another that the nonce used by the apiFetch middleware gets updated. Is there some equivalent we could implement in core? Maybe it ought to just be implemented in Gutenberg? Or as part of some future end-to-end tests implemented in core?

[desrosj]

Spoke with @aduth. This is a must include for 5.2 and he plans on shepherding it.

[aduth]

In 44949:

Scripts: Assign api-fetch nonce with corrected rest_nonce.

As of @wordpress/api-fetch@3.0.0 (introduced in 44812), the apiFetch nonce middleware must have its nonce value assigned explicitly, and will no longer listen for heartbeat ticks automatically. This changeset adds an inline script for the default registration of the api-fetch script handle to assign the nonce value in response to the heartbeat action. In doing so, it removes the now-unused, misnamed rest-nonce property from the heartbeat response, whose original introduction served as temporary compatibility with earlier versions of @wordpress/api-fetch.

See ​https://github.com/WordPress/gutenberg/pull/13451
See #45113

Props adamsilverstein, nerrad .
Fixes #46107 .