Updated with tests and fixed class paths

src/Gateway.php

@@ -516,7 +516,7 @@ public function deletePlan(array $parameters = array())
      */
     public function listPlans(array $parameters = array())
     {
-        return $this->createRequest('App\Lib\Omnipay\Stripe\Message\ListPlansRequest', $parameters);
+        return $this->createRequest('\Omnipay\Stripe\Message\ListPlansRequest', $parameters);
     }
 
     /**

src/Message/ListPlansRequest.php

@@ -13,7 +13,7 @@
  * @see Omnipay\Stripe\Gateway
  * @link https://stripe.com/docs/api/curl#list_plans
  */
-class ListPlansRequest extends \Omnipay\Stripe\Message\AbstractRequest
+class ListPlansRequest extends AbstractRequest
 {
     public function getData()
     {

tests/GatewayTest.php

@@ -152,6 +152,13 @@ public function testDeletePlan()
         $this->assertSame('basic', $request->getId());
     }
 
+    public function testListPlans()
+    {
+        $request = $this->gateway->listPlans(array());
+
+        $this->assertInstanceOf('Omnipay\Stripe\Message\ListPlansRequest', $request);
+    }
+
     public function testCreateSubscription()
     {
         $request = $this->gateway->createSubscription(array('plan' => 'basic'));

tests/Message/ListPlansTest.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Omnipay\Stripe\Message;
+
+use Omnipay\Tests\TestCase;
+
+class ListInvoicesRequestTest extends TestCase
+{
+    public function setUp()
+    {
+        $this->request = new ListPlansRequest($this->getHttpClient(), $this->getHttpRequest());
+    }
+
+    public function testEndpoint()
+    {
+        $this->assertSame('https://api.stripe.com/v1/plans', $this->request->getEndpoint());
+    }
+
+    public function testSendSuccess()
+    {
+        $this->setMockHttpResponse('ListPlans.txt');
+        $response = $this->request->send();
+
+        $this->assertTrue($response->isSuccessful());
+        $this->assertFalse($response->isRedirect());
+        $this->assertNotNull($response->getList());
+        $this->assertNull($response->getMessage());
+    }
+
+    /**
+     * According to documentation: https://stripe.com/docs/api/php#list_plans
+     * This request should never throw an error.
+     */
+    public function testSendFailure()
+    {
+        this->assertTrue(true);
+    }
+}

tests/Mock/ListPlansSuccess.txt

@@ -0,0 +1,46 @@
+HTTP/1.1 200 OK
+Server: nginx
+Date: Mon, 29 Feb 2016 02:40:46 GMT
+Content-Type: application/json
+Content-Length: 6247
+Connection: keep-alive
+Access-Control-Allow-Credentials: true
+Cache-Control: no-cache, no-store
+
+{
+  "object" => "list",
+  "url" => "/v1/plans",
+  "has_more" => false,
+  "data" => [
+    {
+      "id": "test-1",
+      "object": "plan",
+      "amount": 29995,
+      "created": 1483391153,
+      "currency": "usd",
+      "interval": "year",
+      "interval_count": 1,
+      "livemode": false,
+      "metadata": {
+      },
+      "name": "Test 1",
+      "statement_descriptor": "Test 1",
+      "trial_period_days": 14
+    },
+    {
+      "id": "test-2",
+      "object": "plan",
+      "amount": 29995,
+      "created": 1483391153,
+      "currency": "usd",
+      "interval": "year",
+      "interval_count": 1,
+      "livemode": false,
+      "metadata": {
+      },
+      "name": "Test 1",
+      "statement_descriptor": "Test 2",
+      "trial_period_days": 14
+    }
+  ]
+}