Why is using PHPUnit better than creating your own testing script?

Question

Looking through the docs, I see that PHPUnit only offers these functions:

http://www.phpunit.de/manual/current/en/writing-tests-for-phpunit.html#writing-tests-for-phpunit.assertions

All of them can be very easily implemented in a custom testing script, within less than 1K lines...

PHPUnit has 2 MB of files (around 200), which include a huge amount of classes. Also, PHPUnit only runs from the command-line :(

Wouldn't creating my own script be a better idea?

Answer 1

PHPUnit is a beast. It's large, sometimes a little counter-intuitive, and it has it's flaws. Your code would - naturally - be intuitive, and flawless for your direct requirements. I too have often pondered if it wouldn't be a step forward to write my own testing framework, but... it's not. You can finish a rudimentary testing framework in a day, but:

• PHPUnit is integrated in most modern IDE's;
• PHPUnit nicely works with XDebug for code-coverage reports;
• PHPUnit can work together with Selenium for integration tests;
• PHPUnit is used by many programmers, meaning your tests are instantly clear to a lot of them;
• PHPUnit can be integrated into a CI setup such as Travis CI.
• PHPUnit has a mocking library;
• Most importantly: PHPUnit works.

There are a lot of reasons against writing your own.

Answer 2

Two points that @hakre didn't touch upon:

Code coverage

Doing pretty reporting on code coverage (visualizing how much code got executed) is not all that easy even so xDebug enables you do get going rather quickly there are a couple of edge cases and annoyances that take up quite some time to build.

PHPUnit helps you out with a nice report.

Reporting

The most important thing when testing is the ability to quickly figure out what went wrong.

Building a nice diff yourself for all the stuff in PHP (exceptions, objects, strings, xml, json, etc.) is quite time consuming

Also at some point you will want to move to a continous Integration server like Jenkins and a testing framework like PHPUnit will already produce all the needed artifacts (junit.xml, clover.xml) that enables you to set up CI for your projects in half an hour.

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So all in all even if you don't use all the advanced features and helpers (like mocking, process isolation to test legacy code, outputBuffering, exception helpers) you get a base setup that will be able to grow with you when your project grows and get more mature.

CLI only

Btw. there is a web interface to phpunit called Visual PHPUnit that runs in a browser. Even so, to be honest, I don't have any clue as to why anyone would want that. Maybe with out refresh but I'd rather a script loop on a cli terminal than. But to each their own :)