Add unit tests for `marketing/campaigns` API

plugins/woocommerce/tests/php/src/Admin/API/MarketingCampaignsTest.php

@@ -0,0 +1,140 @@
+<?php
+/**
+ * Test the API controller class that handles the marketing campaigns REST response.
+ *
+ * @package WooCommerce\Admin\Tests\Admin\API
+ */
+
+namespace Automattic\WooCommerce\Tests\Admin\API;
+
+use Automattic\WooCommerce\Admin\Marketing\MarketingCampaign;
+use Automattic\WooCommerce\Admin\Marketing\MarketingChannelInterface;
+use Automattic\WooCommerce\Admin\Marketing\MarketingChannels as MarketingChannelsService;
+use WC_REST_Unit_Test_Case;
+use WP_REST_Request;
+
+/**
+ * MarketingCampaigns API controller test.
+ *
+ * @class MarketingCampaignsTest.
+ */
+class MarketingCampaignsTest extends WC_REST_Unit_Test_Case {
+	/**
+	 * Endpoint.
+	 *
+	 * @var string
+	 */
+	const ENDPOINT = '/wc-admin/marketing/campaigns';
+
+	/**
+	 * Set up.
+	 */
+	public function setUp(): void {
+		parent::setUp();
+
+		// Register an administrator user and log in.
+		$this->user = $this->factory->user->create(
+			array(
+				'role' => 'administrator',
+			)
+		);
+		wp_set_current_user( $this->user );
+
+		/**
+		 * MarketingChannels class.
+		 *
+		 * @var MarketingChannelsService $marketing_channels_service
+		 */
+		$this->marketing_channels_service = wc_get_container()->get( MarketingChannelsService::class );
+	}
+
+	/**
+	 * Tests that the marketing campaigns for all registered channels are aggregated and returned by the endpoint.
+	 */
+	public function test_returns_aggregated_marketing_campaigns() {
+		// Create a mock marketing channel.
+		$test_channel_1 = $this->createMock( MarketingChannelInterface::class );
+		$test_channel_1->expects( $this->any() )->method( 'get_slug' )->willReturn( 'test-channel-1' );
+		// Create a mock marketing campaign.
+		$test_campaign_1 = $this->createMock( MarketingCampaign::class );
+		$test_campaign_1->expects( $this->any() )->method( 'get_id' )->willReturn( 'test-campaign-1' );
+		$test_campaign_1->expects( $this->any() )->method( 'get_channel' )->willReturn( $test_channel_1 );
+		// Return the sample campaign by the mock marketing channel.
+		$test_channel_1->expects( $this->any() )->method( 'get_campaigns' )->willReturn( [ $test_campaign_1 ] );
+		// Register the marketing channel.
+		$this->marketing_channels_service->register( $test_channel_1 );
+
+		// Create a second mock marketing channel.
+		$test_channel_2 = $this->createMock( MarketingChannelInterface::class );
+		$test_channel_2->expects( $this->any() )->method( 'get_slug' )->willReturn( 'test-channel-2' );
+		// Create a mock marketing campaign for the second marketing channel.
+		$test_campaign_2 = $this->createMock( MarketingCampaign::class );
+		$test_campaign_2->expects( $this->any() )->method( 'get_id' )->willReturn( 'test-campaign-2' );
+		$test_campaign_2->expects( $this->any() )->method( 'get_channel' )->willReturn( $test_channel_2 );
+		// Return the sample campaign by the second mock marketing channel.
+		$test_channel_2->expects( $this->any() )->method( 'get_campaigns' )->willReturn( [ $test_campaign_2 ] );
+		// Register the second marketing channel.
+		$this->marketing_channels_service->register( $test_channel_2 );
+
+		$request  = new WP_REST_Request( 'GET', self::ENDPOINT );
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertCount( 2, $data );
+		$this->assertEquals(
+			[
+				'test-campaign-1',
+				'test-campaign-2',
+			],
+			array_column( $data, 'id' )
+		);
+		$this->assertEquals(
+			[
+				'test-channel-1',
+				'test-channel-2',
+			],
+			array_column( $data, 'channel' )
+		);
+	}
+
+	/**
+	 * Tests that the marketing campaigns are paginated and then returned by the endpoint.
+	 */
+	public function test_paginates_marketing_campaigns() {
+		// Create a mock marketing channel.
+		$test_channel_1 = $this->createMock( MarketingChannelInterface::class );
+		$test_channel_1->expects( $this->any() )->method( 'get_slug' )->willReturn( 'test-channel-1' );
+		// Return mock campaigns by the mock marketing channel.
+		$test_channel_1->expects( $this->any() )->method( 'get_campaigns' )->willReturn(
+			[
+				$this->createMock( MarketingCampaign::class ),
+				$this->createMock( MarketingCampaign::class ),
+				$this->createMock( MarketingCampaign::class ),
+				$this->createMock( MarketingCampaign::class ),
+				$this->createMock( MarketingCampaign::class ),
+			]
+		);
+		// Register the marketing channel.
+		$this->marketing_channels_service->register( $test_channel_1 );
+
+		$endpoint = self::ENDPOINT;
+		$request  = new WP_REST_Request( 'GET', $endpoint );
+		$request->set_query_params(
+			[
+				'page'     => '1',
+				'per_page' => '2',
+			]
+		);
+		$response = $this->server->dispatch( $request );
+		$headers  = $response->get_headers();
+
+		$this->assertCount( 2, $response->get_data() );
+
+		$this->assertArrayHasKey( 'Link', $headers );
+		$this->assertArrayHasKey( 'X-WP-Total', $headers );
+		$this->assertArrayHasKey( 'X-WP-TotalPages', $headers );
+		$this->assertEquals( 5, $headers['X-WP-Total'] );
+		$this->assertEquals( 3, $headers['X-WP-TotalPages'] );
+	}
+
+}