Script Loader: Remove compression constants and related code by SainathPoojary · Pull Request #8409 · WordPress/wordpress-develop

SainathPoojary · 2025-02-25T19:53:55Z

Remove legacy compression constants (COMPRESS_SCRIPTS, COMPRESS_CSS, ENFORCE_GZIP) and related code.

Before:

After:

Trac ticket: #63017

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

github-actions · 2025-02-25T20:07:33Z

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github-actions · 2025-02-26T07:49:51Z

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

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Props sainathpoojary, westonruter, azaozz.

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… script loading

azaozz · 2025-06-26T19:57:40Z

This looks good. I hope I'll have time this weekend to go over it in more details. One thing to note is that the global $compress_scripts and $compress_css as set in script_concat_settings() would still need to exist for full backwards compatibility.

Would it also be possible to remove checking these constants from class-wp-debug-data.php?

…rd compatibility.

…ebug output

Conflicts are resolved by taking trunk's version and reapplying the removal of the compression code and the `c` argument. Trunk has since moved to `wp_print_script_tag()`, made concatenation opt-in through `wp_should_concatenate_admin_scripts()`, and dropped the `type` attributes from the expected markup in the tests. The removal of the `COMPRESS_SCRIPTS` and `COMPRESS_CSS` rows from the debug data merges cleanly, since trunk already removed them. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Without an `@global` tag, PHPStan treats `$wp_version` as `mixed`, which it rejects when interpolated into the expected loader URLs (`encapsedStringPart.nonString`). The tags are added in the form other tests in these files already use, ahead of a change to those URLs. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Two tests added on trunk since this branch was started expect the `c` argument in the load-scripts.php and load-styles.php URLs, which are no longer printed with it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Scripts and styles have not been compressed from PHP since 5.0.0, so a default of true claimed compression that never happens. The globals are kept for backward compatibility with code that reads them, and a value set by a plugin is still left alone. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

`SCRIPT_DEBUG` disables only concatenation now, and the result of the compression test no longer affects how scripts and styles are loaded, so the header no longer describes the test or its `can_compress_scripts` option. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Nothing reads `$compress_scripts` anymore, so the cases that differed only in its value were redundant, and the test class no longer needs to back up and restore it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

The globals default to false, and the `COMPRESS_SCRIPTS` and `COMPRESS_CSS` constants no longer turn them on, even where the stored result of the compression test used to. A value already set by a plugin is kept. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

The docs standard aligns the types and variable names within a group of tags. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Copilot

🟢 Approval recommended

The endpoints already ignore compression parameters, and regression tests cover the updated settings behavior.

No open issues 🎉

What changed in this PR

Removes obsolete compression controls from the script loader while preserving compatibility globals.

Changes:

Removes compression parameters from concatenated asset URLs.
Defaults compression globals to false without overwriting existing values.
Updates URL expectations and adds settings regression tests.

File	Description
tests/phpunit/tests/dependencies/styles.php	Updates the expected stylesheet URL and global annotations.
tests/phpunit/tests/dependencies/scripts.php	Updates script URLs and removes obsolete compression test setup.
tests/phpunit/tests/dependencies/scriptConcatSettings.php	Tests compression defaults, ignored constants, and preserved globals.
src/wp-includes/script-loader.php	Removes legacy compression handling and updates documentation.

_{Review effort: Balanced}

The removal was merged to the 4.9 branch and first released in 4.9.9, ahead of 5.0.0. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Scripts and styles have not been compressed from PHP since WordPress 4.9.9, when `load-scripts.php` and `load-styles.php` stopped reading the `c` argument in r43580. Even so, the `COMPRESS_SCRIPTS`, `COMPRESS_CSS` and `ENFORCE_GZIP` constants were still documented and read, only to set that unused argument on the loader URLs. That code and documentation are removed. The `$compress_scripts` and `$compress_css` globals are kept for backward compatibility with code that reads them, but they now default to false since nothing is compressed, and a value already set by a plugin is still left alone. The compression test, which still runs in the admin, is to be removed separately. Developed in #8409. Follow-up to r10442, r43580, r64320, r64321. Props sainathpoojary, westonruter, zodiac1978, dpknauss, azaozz. See #44815, #57548, #58302, #65980. Fixes #63017. git-svn-id: https://develop.svn.wordpress.org/trunk@64485 602fd350-edb4-49c9-b593-d223f7449a82

github-actions · 2026-10-18T02:57:16Z

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 64485
GitHub commit: acf82f5

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.

Scripts and styles have not been compressed from PHP since WordPress 4.9.9, when `load-scripts.php` and `load-styles.php` stopped reading the `c` argument in r43580. Even so, the `COMPRESS_SCRIPTS`, `COMPRESS_CSS` and `ENFORCE_GZIP` constants were still documented and read, only to set that unused argument on the loader URLs. That code and documentation are removed. The `$compress_scripts` and `$compress_css` globals are kept for backward compatibility with code that reads them, but they now default to false since nothing is compressed, and a value already set by a plugin is still left alone. The compression test, which still runs in the admin, is to be removed separately. Developed in WordPress/wordpress-develop#8409. Follow-up to r10442, r43580, r64320, r64321. Props sainathpoojary, westonruter, zodiac1978, dpknauss, azaozz. See #44815, #57548, #58302, #65980. Fixes #63017. Built from https://develop.svn.wordpress.org/trunk@64485 git-svn-id: http://core.svn.wordpress.org/trunk@63635 1a063a9b-81f0-0310-95a4-ce76da25c4cd

SainathPoojary force-pushed the remove/compression-constants branch from 26f3114 to 46fcd92 Compare February 26, 2025 05:09

SainathPoojary marked this pull request as ready for review February 26, 2025 07:49

SainathPoojary added 3 commits June 16, 2025 18:49

Script Loader: Remove compression constants and related code

fdbfead

Script Loader: Remove compression parameter from tests

29b4048

Script Loader: Update documentation to clarify usage of constants for…

276ed6a

… script loading

SainathPoojary force-pushed the remove/compression-constants branch from 28be79f to 276ed6a Compare June 16, 2025 13:23

SainathPoojary added 2 commits June 27, 2025 21:30

Script Loader: Restore $compress_scripts and $compress_css for backwa…

81fb948

…rd compatibility.

Script Loader: Remove COMPRESS_SCRIPTS and COMPRESS_CSS checks from d…

140e18d

…ebug output

pento force-pushed the trunk branch from 3af2d27 to 64ede28 Compare July 6, 2026 03:10

westonruter and others added 10 commits October 17, 2026 17:26

Remove the c argument from loader URLs in newer tests

9fd4188

Two tests added on trunk since this branch was started expect the `c` argument in the load-scripts.php and load-styles.php URLs, which are no longer printed with it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Merge branch 'trunk' into remove/compression-constants

9606aca

Add array hint

9b3db70

Align the @global tags added to the concatenation tests

f93baba

The docs standard aligns the types and variable names within a group of tags. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

westonruter requested a balanced review from Copilot October 18, 2026 02:15

Copilot started reviewing on behalf of westonruter October 18, 2026 02:16

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Copilot AI reviewed Oct 18, 2026

View reviewed changes

Correct the version in which PHP compression was removed

8e4e241

The removal was merged to the 4.9 branch and first released in 4.9.9, ahead of 5.0.0. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

github-actions Bot closed this Oct 18, 2026

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Script Loader: Remove compression constants and related code - #8409

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