Sporadic unit test failure in Tests_REST_WpRestUrlDetailsController::test_get_items

[westonruter]

In #54358 via [51973] tests for the URL Details endpoint were introduced. These used a https://placeholder-site.com URL as the test URL for the unit tests in Tests_REST_WpRestUrlDetailsController. As ​discussed in Slack, recently, one of these tests has been failing sporadically:

1) Tests_REST_WpRestUrlDetailsController::test_get_items
Failed asserting that two arrays are identical.
--- Expected
+++ Actual
@@ @@
 Array &0 (
-    'title' => 'Example Website — - with encoded content.'
-    'icon' => 'https://placeholder-site.com/favicon.ico?querystringaddedfortesting'
-    'description' => 'Example description text here. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore.'
-    'image' => 'https://placeholder-site.com/images/home/screen-themes.png?3'
+    'code' => 'rest_invalid_param'
+    'message' => 'Invalid parameter(s): url'
+    'data' => Array &1 (
+        'status' => 400
+        'params' => Array &2 (
+            'url' => 'Invalid parameter.'
+        )
+        'details' => Array &3 ()
+    )
 )

/var/www/tests/phpunit/tests/rest-api/wpRestUrlDetailsController.php:131

Even though the HTTP request is intercepted with a mocked response via the pre_http_request filter, it appears this mocking is not complete. In particular, the wp-block-editor/v1/url-details endpoint includes a url param which has wp_http_validate_url() as its validate_callback. This validation function ends up calling gethostbyname(). Since https://placeholder-site.com is not an actual site, it appears that this gethostbyname() often returns with a failure. I can reproduce the unit test failure by patching wp_http_validate_url() as follows:

src/wp-includes/http.php

@@ -593 +593 @@
                         $ip = $host;
                 } else {
                         $ip = gethostbyname( $host );
-                        if ( $ip === $host ) { // Error condition for gethostbyname().
+                        if ( true || $ip === $host ) { // Error condition for gethostbyname().
                                 return false;
                         }
                 }

I think we should simply use the domain for a real site, like https://example.com.

Trac ticket: https://core.trac.wordpress.org/ticket/64412

[westonruter]

In 61377:

REST API: Use valid host in unit tests for URL Details endpoint.

This ensures that the url parameter is not marked as invalid due to wp_http_validate_url() failing because of a gethostbyname() failure.

Follow-up to [51973].

Props westonruter, swissspidy.
See #54358.
Fixes #64412.

[westonruter]

Re-opening for 6.9 backport consideration.

[peterwilsoncc]

r61377 looks good for merging to the 6.9 branch.

[peterwilsoncc]

In 61378:

REST API: Use valid host in unit tests for URL Details endpoint.

This ensures that the url parameter is not marked as invalid due to wp_http_validate_url() failing because of a gethostbyname() failure.

Follow-up to [51973].

Reviewed by peterwilsoncc.
Merges [61377] to the 6.9 branch.

Props westonruter, swissspidy.
See #54358.
Fixes #64412.

[westonruter]

I just saw this pop up again: ​https://github.com/WordPress/wordpress-develop/actions/runs/20580202810/job/59105886273?pr=10653#step:14:534