Handle trailing slashes in rest_preload_api_request

[spacedmonkey]

When passing a path to rest_preload_api_request that ends in query string, ensure that the parsed path also is untrailingslashit. Follow up to #51636

[antonvlasenko]

I'm working on a patch for this issue.

Trac ticket: https://core.trac.wordpress.org/ticket/57048

[antonvlasenko]

The ​proposed PR updates the rest_preload_api_request function to remove trailing slashes from path parth of the request when preloading data for a specified REST API path.

Before patch:
Preloading /wp/v2/types//?media// would return an array with preloaded data keyed as /wp/v2/types//?media. Only slashes at the end of the path were removed.

After patch:
The path would be /wp/v2/types?media.

Steps to test this PR:

1. Login to the admin panel.
2. Edit an existing post or create a new one and then click Edit.
3. Open the dev tools, inspect the source code of the page. You should see a call to the wp.apiFetch.createPreloadingMiddleware() function and the preloaded data passed as an argument of that function. Typical preloaded requests are:
   • /wp/v2/types?context=view
   • /wp/v2/taxonomies?context=view
   • /wp/v2/blocks?context=edit&per_page=-1
   • /wp/v2/posts/<post-ID>?context=edit
   • /wp/v2/types/post?context=edit
   • /wp/v2/settings

[spacedmonkey]

Me and @swissspidy came across this issue while working web stories together. We patched it in our own code. ​Here is our version of this function.

I can't remember now how we fixed this issue, but look at the git history.

[antonvlasenko]

Replying to spacedmonkey:

Me and @swissspidy came across this issue while working web stories together. We patched it in our own code. ​Here is our version of this function.

I can't remember now how we fixed this issue, but look at the git history.

Thank you for the hint, @spacedmonkey.
I believe this commit addresses the issue in your version of the function: ​https://github.com/GoogleForCreators/web-stories-wp/commit/a7f4977f74d24f73c0a72d23501f6a1eb7ac9337#diff-e38e7938d6df1990969cd7d147a8d590b359fa3a96a33802c85aa5723abf0223R188

The proposed solution in this PR appears to not only resolve the issue you mentioned, but also correct the key at which preloaded data is stored (within the context of array_reduce()).

[spacedmonkey]

I have approved the PR for this change. Looks good to me. I have marked this ticket as commit. Take it away @swissspidy

[swissspidy]

In 59457:

REST API: Remove trailing slashes when preloading requests and there is a query string.

Follow-up to [51648], see #51636.

Props antonvlasenko, swissspidy, spacedmonkey.
Fixes #57048.

Committed in https://core.trac.wordpress.org/changeset/59457