[shail-mehta]

Trac ticket: #65819

What

Extends the existing Tests_Functions::test_wp_get_default_extension_for_mime_type() coverage with PDF and MP3 mime-to-extension mappings.

Test-only; no production code changes.

Why

JPEG, PNG, and unknown mime types were already covered. PDF and MP3 first-extension rows were missing and fit the #65819 cleanup track without a second class.

How

Update tests/phpunit/tests/functions.php:

• Assert application/pdf → pdf
• Assert audio/mpeg → mp3
• Add @covers ::wp_get_default_extension_for_mime_type

Testing Instructions

1. npm run test:php -- --filter test_wp_get_default_extension_for_mime_type
2. npm run test:php -- --filter test_wp_get_default_extension_for_mime_type -c tests/phpunit/multisite.xml
3. npm run test:php -- --filter test_wp_get_default_extension_for_mime_type --order-by=random
4. npm run test:php -- --group functions

Use of AI Tools

• Cursor

[Copilot]

🟢 Approval recommended

There are no active review issues for this test-only addition covering default extensions for known and unknown MIME types.

No open issues 🎉

What changed in this PR

Adds dedicated PHPUnit coverage for wp_get_default_extension_for_mime_type() as part of the #65819 test cleanup effort. No production code changes.

Changes:

• Adds a test class with an explicit @covers annotation.
• Checks the first mapped extension for JPEG, PNG, PDF, and MP3 MIME types.
• Verifies that an unknown MIME type returns false.

File	Description
tests/​phpunit/​tests/​functions/​wpGetDefaultExtensionForMimeType.php	Adds data-driven tests for known MIME types and a test for unknown MIME types.

_{Review effort: Balanced}

[github-actions]

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Props shailu25, lancewillett.

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[lancewillett]

Please extend the existing Tests_Functions::test_wp_get_default_extension_for_mime_type() at tests/phpunit/tests/functions.php:2269–2277 instead. It already covers JPEG's first-extension choice, PNG, and unknown MIME types. PDF/MP3 are new literal rows, but do not require duplicating those existing scenarios in a second class.

Existing coverage.

This is a request to keep the coverage lean, not a reported runtime regression.

_{AI review · gpt-6}

[Copilot]

🟢 Approval recommended

No active review issues are identified for the test-only MIME-to-extension coverage update.

No open issues 🎉

_{Review effort: Balanced}

[shail-mehta]

Thanks for the review!

Addressed in 4378927

[lancewillett]

The revised patch addresses the earlier review requests.

Validated with the related helper patches on current trunk, randomized seed 1101: single-site 773 tests / 1,831 assertions; multisite 764 / 1,822. No failures or errors. The two existing PHPUnit warning-expectation deprecations and one skip were unchanged from the baseline.

Current-head CI and Copilot review checked.

_{AI review · gpt-6}

[lancewillett]

PR #15279 landed in https://core.trac.wordpress.org/changeset/65164