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Mantle Testkit

Mantle Testkit is a standalone package for using the Mantle Testing Framework on non-Mantle based projects. That means that you can use the great features of the Mantle Testing Framework on your existing projects/plugins/themes without needing to do any more refactoring.

This document acts as a guide to transitioning your project to using Mantle Testkit for use of the Mantle Testing Library outside of Mantle.


Testkit should only be used on projects that do not use or define a Mantle application.

Getting Started

This guide assumes that you are working within a wp-content/-rooted WordPress project.

Install mantle-framework/testkit as a dependency

composer require --dev mantle-framework/testkit

Change Test Case

Unit Tests should extend themselves from Testkit's Test_Case class in place of core's WP_UnitTestCase class.

use Mantle\Testkit\Test_Case as Testkit;

class Test_Case extends Testkit {

public function test_example() {
$this->go_to( home_url( '/' ) );
$this->assertQueryTrue( 'is_home', 'is_archive' );

public function test_factory() {
$post = static::factory()->post->create_and_get(); // WP_Post.

// ...

Adjusting Unit Test Bootstrap

Commonly unit tests live inside of plugins or themes. For this use case, we're going to adjust a theme's unit test bootstrap file to load the test framework. Mantle will already be loaded from PHPUnit.

* Testing using Mantle Framework

// Install Mantle Testing Framework normally.

// Install Mantle Testing Framework with some callbacks.
->before( ... )
->after( ... )
->loaded( function() {
// The loaded callback is fired on 'wp_loaded'.
// You can use this callback to load the main file of a plugin, theme, etc.

// Setup any dependencies once WordPress is loaded, such as themes.
switch_theme( 'twentytwenty' );

For more information, read more about the Installation Manager.

Running Tests

Run your tests using ./vendor/bin/phpunit or add a Composer script to allow for composer phpunit.