test-api.php

<?php

/**
 * Class API
 */
class API extends \WP_UnitTestCase {

	/**
	 * @var \DeliciousBrains\Offload\AWS\API
	 */
	private $api;

	/**
	 * @var \WP_Error
	 */
	private $wp_error_response;

	/**
	 * Before each test
	 */
	public function setUp() {
	        /*
		 * Mock the API class so we don't make remote calls
		 * This is a partial mock, in that we are only mocking certain methods
		 */
		$this->api = $this->getMockBuilder( '\DeliciousBrains\Offload\AWS\API' )
		                  ->setConstructorArgs( array( API_KEY, API_SECRET ) )
		                  ->setMethods( array( 'request' ) )
		                  ->getMock();

		$this->wp_error_response = new \WP_Error( 100, 'Issue with AWS' );
	}
	
	function test_get_files() {
		$successful_response       = new \stdClass;
		$successful_response->data = array( array( 'id' => 1, 'name' => 'image.jpg' ) );

		$this->api->expects( $this->any() )
		          ->method( 'request' )
		          ->will( $this->onConsecutiveCalls( $successful_response, $this->wp_error_response, array() ) );

		// Test for successful response
		$this->assertEquals( $successful_response, $this->api->get_files() );

		// Test for WP_Error (Error) response
		$this->assertTrue( is_wp_error( $this->api->get_files() ) );

		// Test for empty array response
		$array_response = $this->api->get_files();
		$this->assertTrue( is_array( $array_response ) );
		$this->assertCount( 0, $array_response );
	}

}