Trailingslash prevents WP Rest API from being cached

[engahmeds3ed]

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• Made sure you’re on the latest version Yes
• Used the search feature to ensure that the bug hasn’t been reported before Yes

Describe the bug
When using our helper plugin which allows caching WP Rest API and permalinks has trailing slash so this blocks the following url from being cached at all:

http://example.com/wp-json/wp/v2

and to make it works we add the trailing slash for those RestAPI urls like:

http://example.com/wp-json/wp/v2/

the line that blocks it from being cached is:

wp-rocket/inc/classes/Buffer/class-cache.php

Lines 79 to 81 in 0300a74

	if ( $this->maybe_allow_wp_redirect() ) {
	return;
	}

To Reproduce
Steps to reproduce the behavior:

1. Activate our helper plugin
2. Visit any WP Rest API url like http://example.com/wp-json/wp/v2
3. Check the cache directory
4. You will not find this json url cached
5. Visit the same url but by adding trailing slash to it like http://example.com/wp-json/wp/v2/
6. Check cache directory
7. You will find it's cached

Expected behavior
I think WP Rest API needs to be excluded from this bailout so it can be cached if this helper is used

Additional context
Slack discussion: https://wp-media.slack.com/archives/C43T1AYMQ/p1682629639240929

Through this discussion, @joejoe04 tried a good solution related to force redirect the urls from not trailingslash to the trailingslash one by using a helper plugin and this worked like a charm.

Backlog Grooming (for WP Media dev team use only)

• Reproduce the problem
• Identify the root cause
• Scope a solution
• Estimate the effort

[piotrbak]

Acceptance Criteria

• When using the helper plugin both versions, with and without / should be cached
• Other trailing slash redirections inside the plugin should not be affected
• Custom Rest API prefix is not redirected, the scope of this PR is only related to /wp-json/. If we see that setting custom Rest API route is being set often, we'll need to create option in our config file to store its value.

[jeawhanlee]

Reproduce the problem ✅

I was able to reproduce the problem

Identify the root cause ✅

Exactly like @engahmeds3ed stated.

Scope a solution ✅

We can simply do an early return when the helper plugin is activated and API urls like that are accessed in

wp-rocket/inc/classes/Buffer/class-cache.php

Line 752 in 3bd3350

private function maybe_allow_wp_redirect(): bool {

if (! preg_match( '#wp\\-json#', $this->config->get_config( 'cache_reject_uri' ) ) && preg_match( '#wp-json/wp/v[0-9]+(/|)$#', $this->tests->get_request_uri_base() ) ) {
    return false;
}

Estimate the effort ✅

[XS]

[vmanthos]

A comment for QA.

The steps Ahmed described require a / to be there in the permalinks. If there isn't, REST API caching works as expected if the REST URI doesn't have a trailing /.

[piotrbak]

Yes, the problem is that before 3.13 both versions were cached, and WordPress doesn't offer redirection on its own :(

[DahmaniAdame]

Temporary fix for this one until the update is released - https://drive.google.com/file/d/19sFnP9NX5van86ZGI-nKmm8tlpVGYa9C/view?usp=sharing