Writing Tests

Testo doesn't care where a test lives, as long as it can be wrapped in a Closure.

Where to Write Tests

• In methods — in regular classes without TestCase inheritance.
• In functions — in standalone functions outside classes.
• In attributes — directly on the method being tested. See Inline Tests.

Test Discovery

Depending on the configuration, Testo can discover tests in several ways:

• Explicit — the #[Test] attribute marks a method, function, or class.
• Conventions — naming patterns like testSomething() methods or *Test classes.
• Custom strategies — you can implement your own test discovery, for example by function-call (like PEST, but without execution) or by class parent, like PHPUnit.

All approaches can be combined in one project or even in one Test Suite.

Less Code

• Parameterization — instead of copying a test for each data set, write one test and pass it different values via data providers.
• Interceptor attributes — extract repetitive boilerplate into reusable attributes.