unit tests for _wp_check_existing_file_names

test for _wp_check_existing_file_names

Trac ticket: [](https://core.trac.wordpress.org/ticket/55192)

Trac ticket: https://core.trac.wordpress.org/ticket/55192

[pbearne]

I found that a missing ext returns false so I have added a return early

[hellofromTonya]

With 6.0 RC1 tomorrow, moving this ticket to 6.1. It can committed when reviewed and ready.

[costdev]

In ​PR 2332, there is a source change in the _wp_check_existing_file_names() that adds || empty( $ext ) to a condition.

The existing datasets in the PR will pass whether or not this condition is added. However, a dataset such as this shows that this is a BC break:

<?php
'found file with no extension' => array(
        'filename' => 'filename',
        'files'    => array( 'filename-scaled' ),
        'expected' => false,
),

Do we want to reject filenames without extensions even if there is a matching existing file (thereby breaking BC), or do we want to retain the existing behaviour? In any case, I think this type of change should have its own ticket, while this is strictly a test ticket.

[hellofromTonya]

This ticket is for tests, not source. However, tomorrow is 6.1 RC1. Since there's been no activity on this ticket for months, punting it to Future Release. Once it's ready, then it can be moved into an active alpha/beta milestone.

[hellofromTonya]

Changing the type to defect as it's not a blessed task.

[pbearne]

I have removed the extra

empty( $ext )

[hellofromTonya]

As of today, I'm no longer a sponsored contributor and am starting a month or more AFK break. To not stand in the way, I'm clearing me as the ticket owner, which opens the ticket for someone to step in to shepherd this ticket forward to resolution.