How to test exceptions and error conditions in PHPUnit?

To test exceptions and error conditions in PHPUnit, you can use the expectException() and expectExceptionMessage() methods.

Here's an example of how you can test for an exception:

Create a test case class that extends PHPUnit\Framework\TestCase.

use PHPUnit\Framework\TestCase;

class MyTestClass extends TestCase
{
    // Your test methods go here
}

In your test method, use the expectException() method and pass the expected exception class as a parameter.

public function testMyMethod()
{
    $this->expectException(MyException::class);

    // Call the method that should throw the exception
    MyTestClass::myMethod();
}

If you want to check the exception message as well, you can use the expectExceptionMessage() method.

public function testMyMethod()
{
    $this->expectException(MyException::class);
    $this->expectExceptionMessage('This is the expected exception message');

    // Call the method that should throw the exception
    MyTestClass::myMethod();
}

Run the test using PHPUnit and it will check whether the specified exception is thrown and whether the exception message matches.

These methods enable you to ensure that your code correctly throws exceptions in response to specific conditions, allowing you to validate error handling and propagation.