[hmbashar]

Summary

Adds tests for Plugin_Upgrader_Skin, which had no coverage (0% on Codecov).

• The constructor uses the defaults and the arguments, and detects an active plugin and a network active plugin.
• after() activates an active plugin again in a frame, but not an inactive plugin, a failed update or an update without an installed plugin.
• after() links to activate the plugin and to the Plugins page, and leaves out the link to activate it after a failure or for a user who cannot activate plugins.
• The update_plugin_complete_actions filter receives the links and the plugin file, and no feedback is given when the links are removed.
• The update count is decremented after a successful update only.

Testing

vendor/bin/phpunit --filter 'Tests_Admin_PluginUpgraderSkin::'
vendor/bin/phpunit -c tests/phpunit/multisite.xml --filter 'Tests_Admin_PluginUpgraderSkin::'
vendor/bin/phpcs tests/phpunit/tests/admin/pluginUpgraderSkin.php

Mutation check: 18 changes to class-plugin-upgrader-skin.php (the conditions of the frame and of the links, the filter, the separator, the nonce, the update count) were each caught by a test. The change to the network active check is caught by the multisite run only.

The skin collects its feedback in the test, because show_message() ends all output buffers.

Trac ticket: https://core.trac.wordpress.org/ticket/66551

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Sonnet 5.5
Used for: Written with AI and manually reviewed by me.

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