WP Tests Starter

Note: You're reading the documentation for the development branch towards version 2.0.0. You'll find the documentation for version 1.0 at the branch version-1

Wp Tests starter is a library that assist you in setting up integration tests for your plugin or library with WordPress core using the official wordpress-develop repository. The main difference to unit tests is that you don't need (and typically don't want) to mock any WordPress function. Instead, you have a fully booted WordPress core in place with an actual connection to a database server.

So if you're mapping your objects to WordPress posts in a ORM-style way your integration test would look like this:

public function testPersistBook(): void {

    $book = new Book('The Da Vinci Code', 'Dan Brown', '2003');
    $testee = new BookRepository($GLOBALS['wpdb']);
    $testee->persist($book); // maps book to WP_Post object and post meta

    self::assertGreaterThan(0, $book->id());

    $wpPost = get_post($book->id());

    self::assertSame('The Da Vinci Code', $wpPost->post_title);
    self::assertSame('2003', get_post_meta($book->id(), '_publishing_year', true));
    self::assertSame('Dan Brown', get_post_meta($book->id(), '_author', true));
}

No mocks required. Just WordPress working inside a PHPUnit test case.

Installation

In order to use Wp Tests Starter you need: a PHP environment with Composer and a MySQL server with a dedicated test database. This database should be completely ephemeral, so do not use any database that contains important data. You'll also need the following four Composer packages installed as dev dependencies:

• inpsyde/wp-tests-starter
• yoast/phpunit-polyfills
• wordpress/wordpress taken from wordpress-develop repository
• phpunit/phpunit

As the last one is not available on packagist.org, you'll have to add the repo manually to your composer.json file by adding:

"repositories": [
    {
        "type": "vcs",
        "url": "https://github.com/WordPress/wordpress-develop"
    }
]

Now you can run

composer require --dev inpsyde/wp-tests-starter yoast/phpunit-polyfills wordpress/wordpress phpunit/phpunit

Note that this will take a while as Composer will analyze the entire WordPress repository on GitHub. (Once a composer.lock is in place it will go faster on the next install run)

Setup your tests

To set up your PHPUnit tests you need two files in place: phpunit.xml.dist and a boostrap.php which gets loaded by PHPUnit before your actual tests are executed. The shown examples of these two files assume a directory structure of your library like this:

├ src/
|  └ MyModule.php
├ tests/
|  ├integration/
|  |  └ MyModuleTest.php
|  └boostrap.php
├ vendor/
├ composer.json
└ phpunit.xml.dist

The following example of the phpunit.xml.dist file tells PHPUnit where the test files resides and contains the database credentials as an environment variable:

<phpunit
    bootstrap="tests/bootstrap.dist.php"
>
    <php>
        <env name="WPTS_DB_URL" value="mysql://user:password@host/db_name?table_prefix=wp_test_"/>
    </php>
    
    <testsuites>
        <testsuite name="integration">
            <directory suffix="Test.php">./tests/integration</directory>
        </testsuite>
    </testsuites>
</phpunit>

The tests/boostrap.php finally loads Wp Tests Starter and WordPress:

<?php

declare(strict_types=1);

namespace MyProject\Tests;

use Inpsyde\WpTestsStarter\WpTestsStarter;

$projectDir = dirname(__DIR__);

require_once $projectDir . '/vendor/autoload.php';

$starter = new WpTestsStarter(
    $projectDir . '/vendor/wordpress/wordpress', // path to the WordPress library
    getenv('WPTS_DB_URL') // Databse credentials in URL format, set in phpunit.xml.dist
);

// Some configuration:
$starter
    // Install WP core as multisite
    ->testAsMultisite()
    // boostrap your plugin or module code
    ->addActivePlugin(static function()  {
        (new MyModule())->init();
    })
    // add filters early
    ->addFilter('my_app.modules', static function(array $modules): array {
        // whatever, it's just an example
        return  $modules;
    })
    //finally load WordPress
    ->bootstrap();

These files just show a short way to run integration tests with WP Tests Starter. You have several other configuration options available through the methods of the WpTestsStarter object.

Run PHPUnit

With this configuration in place you can run PHPUnit to execute all test classes in tests/integration with

vendor/bin/phpunit

On every run, WP Starter will write the configuration to vendor/wordpress/wordpress/wp-config.php and load the WordPress internal bootstrap script which ensures installation of the database tables for example.

Configuration

DB Url

In order to not have to maintain several environment variables you can pass all databse credentials and options via a single parameter like this:

mysql://user:password@localhost:3306/test_db?table_prefix=wp_tests_&charset=utf8mb4&collation=utf8_general_ci

This URL can be passed to WpTestsStarter either by constructor parameter or by useDbUrl() method:

<?php
//either
$starter = new WpTestsStarter($baseDir, $dbUrl);
// or
$starter->useDbUrl($dbUrl);

The URL example above would turn into the following WordPress constants and globals:

<?php
define('DB_HOST', 'localhost:3306');
define('DB_USER', 'user');
define('DB_PASSWORD', 'password');
define('DB_NAME', 'test_db');
define('DB_CHARSET', 'utf8mb4');
define('DB_COLLATE', 'utf8_general_ci');
$GLOBALS['table_prefix'] = 'wp_tests_'

Basically all the values of this URL are optional but keep in mind that you want to have a complete configuration for WordPress. Alternatively you can use explicit values:

$starter
    ->useDbHost('localhost')
    ->useDbUser('user');
    // and so on

License

This repository is a free software, and is released under the terms of the GNU General Public License version 2 or (at your option) any later version. See LICENSE for complete license.

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