README

test-redundancy

test-redundancy finds the tests in a PHPUnit or Pest suite whose covered lines other tests already cover, and shows what each of them asserts beyond those tests. It runs the tests once with per-test coverage and gives every candidate an action: delete it, merge it into a dataset, review it, or keep it as the only test of an error path. The JSON output is built for AI agents; --format=text is built for people.

Requirements

Installation

composer require --dev pekral/test-redundancy

The tool keeps its local state (the coverage map, the baseline, the file durations and the runner cache) in .test-redundancy/. Add it to .gitignore:

echo ".test-redundancy/" >> .gitignore

Configuration

Optional. Without a test-redundancy.json in the project root, the tool reads src/ and app/, runs 2 parallel processes, and picks vendor/bin/pest when it exists, otherwise vendor/bin/phpunit. The keys source, ignore, env, processes, map and runner are described in Configuration.

Quick start

1. Analyse a test folder and read the report:

   vendor/bin/test-redundancy tests/Unit/Billing --format=text

   [!WARNING] The tests always run in parallel, on the test tokens 1…processes. Never start the tool next to another run of the same suite.

2. Act on each candidate, from the top: the report puts the slowest candidates first. Follow its steps, see How to read a candidate.

3. Verify that every source line the analysed tests covered is still covered:

   vendor/bin/test-redundancy verify

   verify exits with 1 and lists the lost lines when a change dropped coverage.

Without a path, analyse takes the test files the branch changes against origin/HEAD, or against --base. vendor/bin/test-redundancy analyse --help lists every option.

What it does

• Finds candidates: test cases whose covered lines other test cases already cover, every dataset row separately.
• Compares contracts, not only lines: differsBy lists the literals, calls and keys a candidate has and its covering test lacks.
• Says what to do: every candidate has an action and numbered steps; a test of an error path that no covering test asserts is marked keep.
• Starts where it pays: files and candidates are ordered by the time each candidate took, so the slowest redundant tests come first.
• Proves nothing was lost: verify fails when a source line the last analysis covered is no longer covered.
• Compares across files: map builds a per-test coverage map, and analyse --across compares with every mapped test.

Documentation

• Usage: commands, options, how the tool runs your tests, configuration, verify and --across.
• Reading the report: the actions, the JSON fields, error paths, input combinations, failed tests and skipped files.
• Reference: the exact rules for delete and merge-into-dataset, how differsBy names a difference, and how the analysis works.
• Development: the Composer scripts and the CI matrix.

Testing

Contributing needs PHP 8.4+ with pcov.

composer install
composer test

composer check runs the full quality gate: Composer normalize, PHPCS, Pint, Rector, PHPStan, the security audit and the tests with 100% coverage.

Changelog

See CHANGELOG.

Contributing

See CONTRIBUTING.

Security

See the security policy.

License

MIT. See LICENSE.