Issue related to SapphireTest unit testing library in SIlverStripe

SilverStripe version: 4.13

Issue creating SapphireTest unit test case in SilverStripe:

I created a unit test php file that gets a URL and checks if all the h1 tags having class custom-heading-title has the CSS style color:red to it…
This is the code I have written.(Found by clicking on URL below)

I am executing this code using terminal command
vendor/bin/phpunit app/tests/StyleTest.php and receiving following error

Error: Call to undefined method StyleTest::get()

I tried a lot but was unable to resolve this issue. Would much appreciate if anyone can help me on this. There are no online tutorials for this.

I have put the entire code below if the above link does not work. I have placed this code in app → tests → StyleTest.php

use SilverStripe\Dev\SapphireTest;
use SilverStripe\Control\Director;
use SilverStripe\Control\HTTPRequest;
use SilverStripe\Assets\File;
use SilverStripe\Assets\Image;

class MyTest extends SapphireTest
    public function testCssPropertyExists()
        $page = $this->get('/my-page/');
        $html = $page->getBody();

        $dom = new \DOMDocument();
        $xpath = new \DOMXPath($dom);
        $elements = $xpath->query('//div[@id="my-element"]');

        $this->assertEquals(1, $elements->length);

        $styleAttribute = $elements[0]->getAttribute('style');
        $this->assertStringContainsString('color: red;', $styleAttribute);

    private function get($url)
        $request = new HTTPRequest('GET', $url);
        $controller = Director::test($url);
        $response = $controller->getResponse();

        return $response;

The get() method isn’t defined in your custom class, nor in SapphireTest or any other class in the inheritance chain. So it can’t be called.

I’m guessing you saw $this->get() in the functional testing docs - it’s important to note that the functional testing docs use FunctionalTest as the base class, so you should have class StyleTest extends FunctionalTest if you want to use that functionality.