WordPressでWP_Rewriteの単体テストのサンプルです。

test-wp-rewrite.php

<?php
/**
 * WP_Rewriteテスト
 *
 * @package   InfoTown
 * @author    Hiroshi Sawai <info@info-town.jp>
 * @copyright Hiroshi Sawai
 */
class InfoTown_Rewrite_Test extends WP_UnitTestCase {
	/**
	 * @group rewrite
	 */
	public function test_wp_rewrite_empty_rule() {
		global $wp_rewrite;
		$rules = $wp_rewrite->rewrite_rules();
		$this->assertEmpty( $rules );
	}

	/**
	 * Test permalink.
	 *
	 * @group rewrite
	 */
	public function test_wp_rewrite_permalink() {
		/** @var WP_Rewrite $wp_rewrite */
		global $wp_rewrite;
		// Set permalink.
		$wp_rewrite->set_permalink_structure( '/%category%/%post_id%.html' );
		// Test rewrite rule is not empty
		$this->assertNotEmpty( $wp_rewrite->rewrite_rules() );
		// Test permalink rule.
		$this->assertEquals( '/%category%/%post_id%.html', $wp_rewrite->permalink_structure );
		$cat     = $this->factory->category->create_and_get(
			[
				'name' => 'Sample category',
				'slug' => 'sample'
			]
		);
		$post_id = $this->factory->post->create( [ 'post_category' => [ $cat->term_id ] ] );
		$actual  = get_permalink( $post_id );
		// Test permalink.
		$this->assertEquals(
			'http://example.org/' . $cat->slug . '/' . $post_id . '.html',
			$actual
		);
	}

	/**
	 * Test extra permastruct.
	 *
	 * @group rewrite
	 */
	public function test_wp_rewrite_extra_permastruct_category() {
		/** @var WP_Rewrite $wp_rewrite */
		global $wp_rewrite;
		// Set extra rule(category rule).
		$wp_rewrite->add_rewrite_tag( '%category%', '(.+?)', 'category_name=' );
		$wp_rewrite->add_permastruct( 'category', '/category/%category%', false );
		$wp_rewrite->flush_rules();
		// Set post.
		$cat = $this->factory->category->create_and_get(
			[
				'name' => 'Test category',
				'slug' => 'test'
			]
		);
		$this->factory->post->create( [ 'post_category' => [ $cat->term_id ] ] );
		$this->go_to( '/category/' . $cat->slug );
		// Test rule.
		$this->assertTrue( is_category() );
		$this->assertEquals( 'http://example.org/category/test', get_category_link( $cat->term_id ) );
	}

	/**
	 * @group rewrite
	 */
	public function test_wp_rewrite_extra_permastruct_year() {
		/** @var WP_Rewrite $wp_rewrite */
		global $wp_rewrite;
		$wp_rewrite->add_rewrite_tag( '%year%', '([0-9]{4})', 'year=' );
		$wp_rewrite->add_permastruct( 'year', '/year/%year%', false );
		$wp_rewrite->flush_rules();
		$date = new \DateTime();
		$year = $date->format( 'Y' );
		$this->factory->post->create();
		$this->go_to( '/year/' . $year );
		$this->assertTrue( is_year() );
	}

	/**
	 * @group rewrite
	 */
	public function test_wp_rewrite_extra_permastruct_date() {
		/** @var WP_Rewrite $wp_rewrite */
		global $wp_rewrite;
		$wp_rewrite->add_permastruct( 'date', '%year%/%monthnum%/%day%', false );
		$wp_rewrite->flush_rules();
		$date = new \DateTime();
		$this->factory->post->create();
		$this->go_to( '/date/' . $date->format( 'Y' ) . '/' . $date->format( 'm' ) . '/' . $date->format( 'd' ) );
		$this->assertTrue( is_date() );
	}
}