rest-api-test-case.php

<?php

/**
 * @rest-api-base-namespace: /wp/v2
 * @rest-api-base-path: /posts
 */
class REST_API_Endpoint_Test extends WP_REST_Unit_Test_Case {

	function test_create_item() {

		$response = $this->create_item( array(
			'title' => 'Test',
		));

		$this->assertResponseEquals( array(
			'code'    => 200,
			'data'    => array(
				'id'     => 1,
				'author' => 1,
			),
			'links'   => array(
				'author' => '/wp/v2/users/1',
			),
		), $response );

		// test for a subset of any data, e.g. a specific key is in the body
		$this->assertResponseContains( array(
			'data'    => array(
				'author' => 1,
			),
			'links'   => array(
				'author' => '/wp/v2/users/1',
			),
		), $response );

		$this->assertResponseCollectionEquals( array(
			...
		));
	}
}