Const In PHPUnit Test Case

Question

I have a const limit in my php function as given below.

 const limit = 5 ;
 function limit_check($no_of_page)
 {
       if($no_of_page < const limit)
       return true;       else    return false;
 }

Now I want to write the unit cases for this using PHPUnit, but in unit cases I want to reset the limit so that my test cases not fail if someone resets limit. How to set the php const in my unit test function?

Answer 1

Normally, you have set this limit for a coding reason, and therefore, you should check and enforce this limit as it likely has a reason for being there. However, if not, then you could have something more like the following:

class FOO
{
    const limit = 5;
    private $PageNumberLimit;

    public function __construct($PageLimit = self::limit)
    {
        $this->SetPageLimit($PageLimit);
    }

    public function SetPageLimit($PageLimit)
    {
        $this->PageNumberLimit = $PageLimit;
    }

    public function limit_check($no_of_page)
    {
        if($no_of_page < $this->PageNumberLimit)
            return true;
        else
            return false;
    }
}

Then the tests:

class FOO_TEST extends PHPUnit_Framework_TestCase
{
    protected $FooClass;

    protected function setUp()
    {
        $this->FooClass = new FOO();
    }

    public function testConstantValue()
    {
        $ReflectObject = new ReflectionClass('FOO');
        $this->assertEquals(5, $ReflectObject->getConstant('limit'), 'Test that the default Page Limit of 5 was not changed');
    }

    public function testDefaultLimitUsed()
    {
        $ReflectObject = new ReflectionClass('FOO');
        $this->assertEquals($ReflectObject->getConstant('limit'), $this->FooClass->PageNumberLimit, 'Test that the default Page Limit is used by matching value to constant.');
    }

    public function testlimit_check()
    {
        $this->assertTrue($this->FooClass->limit_check(4), 'Page Number is less than Limit');
        $this->assertFalse($this->FooClass->limit_check(5), 'Page Number is equal to Limit');
        $this->assertFalse($this->FooClass->limit_check(6), 'Page Number is greater than Limit');
    }

    public static function PageNumberDataProvider()
    {
        return array(
            array(4),
            array(5),
            array(6),
            );
    }

    /**
     * @dataProvider PageNumberDataProvider
     */
    public function testSetPageLimitWithConstructor($NumberOfPages)
    {
        $Foo = new FOO($NumberOfPages);         // Create the class using the constructor

        $this->assertTrue($Foo->limit_check($NumberOfPages - 1), 'Page Number is less than Limit');
        $this->assertFalse($Foo->limit_check($NumberOfPages), 'Page Number is equal to Limit');
        $this->assertFalse($Foo->limit_check($NumberOfPages + 1), 'Page Number is greater than Limit');
    }

    /**
     * @dataProvider PageNumberDataProvider
     */
    public function testSetPageLimitWithSetPageLimit($NumberOfPages)
    {
        $this->FooClass->SetPageLimit($NumberOfPages);          // Set the number using the public function

        $this->assertTrue($Foo->limit_check($NumberOfPages - 1), 'Page Number is less than Limit');
        $this->assertFalse($Foo->limit_check($NumberOfPages), 'Page Number is equal to Limit');
        $this->assertFalse($Foo->limit_check($NumberOfPages + 1), 'Page Number is greater than Limit');
    }
}