[wp-trac] [WordPress Trac] #50209: Remove all uploads between test methods

[WordPress Trac]

#50209: Remove all uploads between test methods
------------------------------+-----------------------------
 Reporter:  Frank Klein       |      Owner:  (none)
     Type:  enhancement       |     Status:  new
 Priority:  normal            |  Milestone:  Awaiting Review
Component:  Build/Test Tools  |    Version:  4.0
 Severity:  normal            |   Keywords:
  Focuses:                    |
------------------------------+-----------------------------
 Commit r29120 added a curious feature to the WordPress testing framework:
 selective uploads deletion between test runs.

 What it means is that the first time that `WP_UnitTestCase::setUp()` is
 called for a test case, it will create a list of all files contained in
 the uploads directory. This list, stored in the static `$ignore_files`
 property, allows to selectively delete files uploaded during tests.

 This code was added so that tests can be run against a development
 installation of WordPress. In opposition to running tests against a
 throwaway installation, as should be the case.

 There are three issues with this behavior:
 1. Scanning the uploads directory is slow. If you have too many files in
 that directory, the test runner will "hang" before running the first test.
 Ultimately it will result in a memory exhaustion error.
 2. Attachments are not properly deleted. `_delete_all_data()` runs a SQL
 query that deletes the database entries of attachments, but not the
 associated files. Since the function is called before
 `wpTearDownAfterClass` runs, there's no way to do manual cleanups in
 tests. The next test case that gets booted up will add the remaining files
 to the list of files to ignore, making it impossible to do selective
 uploads deletion. See #41978.
 3. There is no automatic clean up of uploads between test methods or test
 cases, leaving files lingering around. Even after all tests have been run.

 In short this approach is slow, half-baked, and unneeded. We should
 therefore remove it, and have uploads be cleared the same as any other
 fixture.

 Since this behaviour has been around for years now, we can't unfortunately
 just remove it, so I propose that we use a feature flag for disabling it.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/50209>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform