[huzaifaalmesbah]

Description

Adds tests for the Plugin_Upgrader callbacks that run around a plugin upgrade: deactivate_plugin_before_upgrade(), active_before(), active_after() and delete_old_plugin(). None of them had tests.

The tests replace the filesystem global with a mock, so no files are touched, and use the wp_doing_cron filter to switch between manual and background upgrades. They cover:

• an error response being passed through by all four callbacks without side effects;
• a missing or empty plugin being a bad_request error;
• an active plugin being deactivated silently (no deactivation hooks) before a manual upgrade, and being left active in cron or when it was already inactive;
• maintenance mode being enabled and disabled for an active plugin in a background upgrade, and left alone for a manual upgrade, an inactive plugin or a bulk upgrade;
• the old plugin being deleted recursively for a plugin in a directory and as a single file otherwise, nothing being deleted when the directory is already gone, and remove_old_failed when the deletion fails.

The maintenance mode test runs in a separate process, because the maintenance file is written with FS_CHMOD_FILE, which WP_Filesystem() defines. Removing or changing each branch of the four callbacks makes at least one test fail.

This is a test-only change; no production code is modified.

Testing Instructions

1. Run the tests on single site:
   npm run test:php -- --filter Tests_Admin_PluginUpgraderUpgradeHooks
2. Run them on multisite:
   npm run test:php -- --filter Tests_Admin_PluginUpgraderUpgradeHooks -c tests/phpunit/multisite.xml
3. Run them in random order:
   npm run test:php -- --filter Tests_Admin_PluginUpgraderUpgradeHooks --order-by=random
4. Run the plugins and upgrade groups:
   npm run test:php -- --group plugins,upgrade
5. Run PHPCS on the test file:
   node ./tools/local-env/scripts/docker.js run --rm php ./vendor/bin/phpcs tests/phpunit/tests/admin/pluginUpgraderUpgradeHooks.php

Trac ticket: https://core.trac.wordpress.org/ticket/65819

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 5.5
Used for: Brainstorming edge-case scenarios and drafting test boilerplate; test architecture, assertions, and local PHPUnit verification were written and validated by me.

[github-actions]

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.

Core Committers: Use this line as a base for the props when committing in SVN:

Props huzaifaalmesbah, lancewillett, mukesh27.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[Copilot]

🟡 Changes recommended

The maintenance test needs per-callback assertions to detect reversed enable/disable behavior.

1 open issue

• Tests fail to verify maintenance state after each callback · New

What changed in this PR

Adds unit coverage for WordPress plugin-upgrade callbacks without changing production code.

Changes:

• Tests error handling and silent plugin deactivation.
• Covers maintenance-mode conditions and old-plugin deletion using a mocked filesystem.

File	Description
tests/​phpunit/​tests/​admin/​pluginUpgraderUpgradeHooks.php	Adds tests for four Plugin_Upgrader callbacks.

_{Review effort: Balanced}

[lancewillett]

Confirmed locally: swapping the maintenance-mode booleans in active_before() and active_after() still passes this test (1 test, 3 assertions). The shared call counts do not distinguish the two callbacks.

Please track the mocked maintenance-file state and assert that it exists immediately after active_before() and is absent immediately after active_after(), or test each callback independently. This should fail when their enable/disable behavior is reversed.

_{AI review · gpt-6}

[lancewillett]

Please strengthen the maintenance-mode case as described in the inline thread. I confirmed that reversing the enable/disable callbacks leaves it green, so it does not yet protect the behavior named by the test. The other local checks pass.

_{AI review · gpt-6}

[mukeshpanchal27]

The tests match the Plugin_Upgrader callbacks, and the mocked filesystem means no real .maintenance file is written. One suggestion inline.

[mukeshpanchal27]

This test runs in a separate process only so it can define FS_CHMOD_FILE. Each separate process starts WordPress again, which slows the suite. A guard would let it run in the normal process:

if ( ! defined( 'FS_CHMOD_FILE' ) ) {
	define( 'FS_CHMOD_FILE', 0644 );
}

The put_contents() expectation would then use FS_CHMOD_FILE instead of 0644, in case an earlier test already defined the constant with another value. With that change, @runInSeparateProcess and @preserveGlobalState disabled could go.

[huzaifaalmesbah]

Thanks, done in 9f4985a. The test now guards the define(), expects FS_CHMOD_FILE, and runs in the main process. The wpUpgrader.php tests that define the constant all run in separate processes, so they are not affected, and the whole tests/admin directory passes in both default and random order.