phpunitHow to expect an error with PHPUnit?

PHPUnit is a unit testing framework for the PHP programming language. It can be used to expect errors in a program by writing test cases that check for expected errors.

For example, the following code block will expect an error when the function divideByZero is called:

<?php

class ErrorTest extends \PHPUnit\Framework\TestCase
{
    public function testDivideByZero()
    {
        $this->expectException(\DivisionByZeroError::class);
        divideByZero();
    }
}

When the test is run, the following output will be displayed:

PHPUnit 8.5.8 by Sebastian Bergmann and contributors.

E                                                                   1 / 1 (100%)

Time: 00:00.001, Memory: 6.00 MB

There was 1 error:

1) ErrorTest::testDivideByZero
DivisionByZeroError: Division by zero

/path/to/ErrorTest.php:7

ERRORS!
Tests: 1, Assertions: 0, Errors: 1.

Code explanation

1. $this->expectException(\DivisionByZeroError::class); - This line tells PHPUnit to expect an error of type DivisionByZeroError.
2. divideByZero(); - This line calls the function divideByZero which will cause the error.

Helpful links

• PHPUnit Documentation
• PHPUnit Tutorial

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