Tests: Add unit test coverage for Amend_Check_Result trait

[noruzzamans]

Description

This pull request introduces a comprehensive unit test suite for the WordPress\Plugin_Check\Traits\Amend_Check_Result trait (includes/Traits/Amend_Check_Result.php).

Amend_Check_Result is a core architectural trait composed by over 25 check classes across WordPress/plugin-check (including Plugin_Content_Check, Direct_File_Access_Check, File_Type_Check, Trademarks_Check, Setting_Sanitization_Check, Write_File_Check, Safe_Redirect_Check, and No_Unfiltered_Uploads_Check) to format and record issue notices into Check_Result.

While companion traits such as File_Editor_URL, Readme_Utils, Language_Utils, License_Utils, Version_Utils, and Amend_DB_Base_Prefix possess dedicated unit tests under tests/phpunit/tests/Traits/, Amend_Check_Result previously lacked dedicated unit test coverage.

Test Coverage Highlights

The new test suite in tests/phpunit/tests/Traits/Amend_Check_Result_Tests.php validates:

• Error Reporting (add_result_error_for_file): Confirms that errors are added to the result stack, error count increments, and warning stack remains unaffected.
• Warning Reporting (add_result_warning_for_file): Confirms that warnings are added to the result stack, warning count increments, and error stack remains unaffected.
• Boolean Flag Casting (add_result_message_for_file): Verifies proper casting of truthy and falsy values to error versus warning stacks.
• Plugin Path Stripping: Asserts that absolute file paths within the plugin root have the base path stripped, producing clean relative file paths in message metadata.
• Relative Path Handling: Validates that paths already relative to the plugin root are preserved.
• Default Arguments: Verifies defaults for line (0), column (0), docs (''), and severity (5).
• Custom Arguments: Validates proper preservation of custom line, column, documentation URL, and severity levels.
• Editor Link Integration: Asserts integration with File_Editor_URL and wp_plugin_check_validation_error_source_url filter to populate 'link' in message metadata.
• Permission Fallback: Confirms editor link defaults to null when the user lacks edit capabilities and no custom filter is set.
• Message Accumulation: Ensures multiple errors and warnings across different files and coordinates accumulate without collision.

Quality & Standards

• 100% test-only addition (0 production code modifications).
• Fully validated with composer lint (PHPCS VIPWPCS / WordPress-Core).
• Fully validated with composer phpstan (PHPStan Level 8, 0 errors).
• All 10 tests and 45 assertions pass cleanly via PHPUnit.

[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.

If you're merging code through a pull request on GitHub, copy and paste the following into the bottom of the merge commit message.

Co-authored-by: noruzzamans <noruzzaman@git.wordpress.org>
Co-authored-by: davidperezgar <davidperez@git.wordpress.org>

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

[davidperezgar]

Thanks for your contribution. The test setup creates a symlink in WP_PLUGIN_DIR, but tear_down() never removes it. This leaves global fixture state behind for the remainder of the suite — and potentially in the wp-env volume — which can affect later tests that enumerate plugins or use the same path. Please clean it up in tear_down(), ideally tracking whether this test class created the symlink so it does not remove one owned by another test.

[noruzzamans]

Thanks for catching this, @davidperezgar! That's a great point regarding global fixture state leakage and preserving symlinks owned by other tests or prior suite runs.

I have updated the test class in commit 8496bb1b:

1. Added a $fixture_symlink_created property to explicitly track when symlink() was created by this test class.
2. In tear_down(), safely unlink() the fixture symlink only if $fixture_symlink_created is true and reset tracking state.

Local PHPCS (composer run-script lint) and PHPStan analyse pass cleanly with 0 errors.