https://github.com/trismegiste/scarymutantsandnicetests

Scary Mutants and Nice Tests is tool to test PhpUnit tests with on-the-fly-produced mutants
https://github.com/trismegiste/scarymutantsandnicetests

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Scary Mutants and Nice Tests is tool to test PhpUnit tests with on-the-fly-produced mutants

• Host: GitHub
• URL: https://github.com/trismegiste/scarymutantsandnicetests
• Owner: Trismegiste
• Created: 2013-06-03T08:00:40.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-06-05T09:38:07.000Z (over 11 years ago)
• Last Synced: 2023-03-15T19:06:15.662Z (almost 2 years ago)
• Language: PHP
• Size: 137 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Scary Mutants and Nice Tests

A wrapper for PHPUnit to test your tests. Highly experimental.

## What

"Yo dawg, I herd you like tests so I put a mutant in your tests

so u can test your tests" - xzibit

That's the spirit. 

## How

More seriously, this tool makes 3 things :

 * scans all classes in your phpunit-tested package (with a phpunit.xml)

 * intercepts the bootstrap autoloader to make its own loading

 * creates a mutant on the fly to replace the autoloaded class

## Why

Because we can ! In fact it's an effective way to validate if your tests

are doing their job or not. If a mutant passes the tests, it means your test is

not complete, even if you have 100% code-coverage.

Futhermore, objects and classes, like species, evolve and are mutating with time.

A nice unit test is efficient if it can select, like darwinism, the good class

from the buggy (scary) mutants.

## How much

Beware, since there is a parsing and an evaluation of each autoloaded classes,

this could be slow, very slow.

Despite tests on multiple packages, a test could break even without mutant :

 - failure on autoloading

 - files not found because of relative path

 - no PSR-0 compliant

...

## Where

... is the mutant ? Nowhere, it is created by a Visitor on the fly. 

It is in the Visitor folder and is named : "MadScientist".

## When

... to press Ctrl-C ? Well, mutation causes not only failure but also 

immortal creatures. Your tests could infinitly loop and then you have to break it.

## Who

... are the mutants ? At this time, I only alter false to true and true to false.

By modifiying constants' classes to produce mutants, you can tests if future 

minor alterations will break unit tests. Future plans include :

 - default values of properties

 - default values of arguments

 - hard-coded magic number

 - Liskov substitution

## Not invented here

That's right. Other tools already exist but they require php extensions, some

compiling of C modules... The point here is it is full PHP. Even X-Debug is not

required.