Add unit tests for `marketing/channels` API

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

@@ -0,0 +1,69 @@
+<?php
+/**
+ * Test the API controller class that handles the marketing channels REST response.
+ *
+ * @package WooCommerce\Admin\Tests\Admin\API
+ */
+
+namespace Automattic\WooCommerce\Tests\Admin\API;
+
+use Automattic\WooCommerce\Admin\Marketing\MarketingChannelInterface;
+use Automattic\WooCommerce\Admin\Marketing\MarketingChannels as MarketingChannelsService;
+use WC_REST_Unit_Test_Case;
+use WP_REST_Request;
+
+/**
+ * MarketingChannels API controller test.
+ *
+ * @class MarketingChannelsTest.
+ */
+class MarketingChannelsTest extends WC_REST_Unit_Test_Case {
+	/**
+	 * Endpoint.
+	 *
+	 * @var string
+	 */
+	const ENDPOINT = '/wc-admin/marketing/channels';
+
+	/**
+	 * 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 registered marketing channels are returned by the endpoint.
+	 */
+	public function test_returns_registered_marketing_channels() {
+		// Register marketing channel.
+		$test_channel_1 = $this->createMock( MarketingChannelInterface::class );
+		$test_channel_1->expects( $this->any() )->method( 'get_slug' )->willReturn( 'test-channel-1' );
+		$test_channel_1->expects( $this->any() )->method( 'get_name' )->willReturn( 'Test Channel One' );
+		$this->marketing_channels_service->register( $test_channel_1 );
+
+		$request  = new WP_REST_Request( 'GET', self::ENDPOINT );
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertCount( 1, $data );
+		$this->assertEquals( 'test-channel-1', $data[0]['slug'] );
+		$this->assertEquals( 'Test Channel One', $data[0]['name'] );
+	}
+
+}