Unit Test Implementation in Magento 2

As in the previous blog, we have learned a few commands to perform unit testing. Today we will create a small custom module in Magento 2 and will write test cases for it.

Let’s start, now I am assuming that you are aware of the Magento Directory structure and know how to create a custom module in Magento 2.

In this blog, we are going to create a model for calculator where we can perform basic addition operation.

Step 1: Create your custom module and register it, in my case, I have created a module Webkul_HelloUnitTest.

Step 2: Create a model  Calculator here :
app/code/<vendorname>/<modulename>/Model/Calculator.php

<?php

namespace Webkul\HelloUnitTest\Model;

class Calculator {
    /**
     * This function will perform the addition of two numbers
     *
     * @param float $a
     * @param float $b
     * @return float
     */
    public function addition($a ,$b) {
        return $a + $b;
    }
}

Above We have a class calculator and inside it, there is a function addition that will receive 2 values and return the addition as a result.

Now let’s create a unit test model for the above.

Step 3:  Create a test model here :
app/code/<vendorname>/<modulename>/Test/Unit/Model/Calculator.php

<?php

namespace Webkul\HelloUnitTest\Test\Unit\Model;

class Calculator extends  \PHPUnit\Framework\TestCase {

    protected $_objectManager;
    protected $_desiredResult;
    protected $_actulResult;
    protected $_calculator;
    /**
     * Unset the variables and objects after use
     *
     * @return void
     */
    public function tearDown(): void {
        
    }

    /**
     * Used to set the values to variables or objects.
     *
     * @return void
     */
    public function setUp(): void {
        $this->_objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
        $this->_calculator = $this->_objectManager->getObject("Webkul\HelloUnitTest\Model\Calculator");
        //can do stuff
    }
    /**
     * This function will perform the addition of two numbers
     *
     * @param float $a
     * @param float $b
     * @return float
     */
    public function testAddition() { 
         $this->_actulResult = $this->_calculator->addition(7.0,3.0);
         $this->_desiredResult = 10.0;
         $this->assertEquals($this->_desiredResult, $this->_actulResult);
    }
}

Step 4: Run any of the commands of my previous blog.
Here I have a command to run the test for the particular file.

php vendor/bin/phpunit -c dev/tests/unit/phpunit.xml.dist app/code/Webkul/HelloUnitTest/Test/Unit/Model/Calculator.php

This will return the below output.
On Success :

On Failure: When I changed the logic to subtract.

A few types of Assertions are as below  :

assertTrue($x)	Fail if $x is false
assertFalse($x)	Fail if $x is true
assertNull($x)	Fail if $x is set
assertNotNull($x)	Fail if $x not set
assertIsA($x, $t)	Fail if $x is not the class or type $t
assertNotA($x, $t)	Fail if $x is of the class or type $t
assertEqual($x, $y)	Fail if $x == $y is false
assertNotEqual($x, $y)	Fail if $x == $y is true
assertWithinMargin($x, $y, $m)	Fail if abs($x - $y) < $m is false
assertOutsideMargin($x, $y, $m)	Fail if abs($x - $y) < $m is true
assertIdentical($x, $y)	Fail if $x == $y is false or a type mismatch
assertNotIdentical($x, $y)	Fail if $x == $y is true and types match
assertReference($x, $y)	Fail unless $x and $y are the same variable
assertClone($x, $y)	Fail unless $x and $y are identical copies
assertPattern($p, $x)	Fail unless the regex $p matches $x
assertNoPattern($p, $x)	Fail if the regex $p matches $x
expectError($x)	Fail if matching error does not occour
expectException($x)	Fail if matching exception is not thrown
ignoreException($x)	Swallows any upcoming matching exception
assert($e)	Fail on failed expectation object

Note: If you want to go deep in the topic you can check PHPUnit.

If you require technical support, feel free to email us at [email protected].

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