infection

Infection is a command line tool designed for mutation testing in various programming languages like PHP, Java, and C#. It helps developers identify weak areas in their code by introducing controlled mutations and observing the impact on the tests.

By randomly altering the code's logic, Infection creates multiple variations of the codebase called mutants. It then runs the test suite against each mutant to check if the tests detect these variations. If a mutant survives undetected, it suggests that the test suite does not have adequate coverage.

Infection supports various mutation operations like replacing logical operators, swapping conditions, modifying operands, and more. Developers can configure which mutations to apply using configuration files in their projects.

It offers integration with popular testing frameworks like PHPUnit and PHPspec, making it easy to incorporate into existing testing workflows.

Infection provides various reports outlining the results of the mutation testing, such as mutation score, number of mutants killed, and killed mutant details. These reports help developers assess the effectiveness of their tests and prioritize areas for improvement.

To speed up the process, Infection employs strategies like parallel execution of tests, caching of test results, and selectively mutating only impacted parts of the codebase.

With its flexibility and compatibility across multiple languages, Infection serves as an efficient tool to drive developers towards writing more robust and comprehensive test suites.