[Payment Request] Error message screen

ios/chrome/browser/payments/payment_request_error_view_controller_unittest.mm

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/payments/payment_request_error_view_controller.h"
+
+#include "base/mac/foundation_util.h"
+#include "base/memory/ptr_util.h"
+#import "ios/chrome/browser/payments/cells/payments_text_item.h"
+#import "ios/chrome/browser/ui/collection_view/collection_view_controller_test.h"
+#include "ios/chrome/grit/ios_strings.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class PaymentRequestErrorViewControllerTest
+    : public CollectionViewControllerTest {
+ protected:
+  CollectionViewController* NewController() override NS_RETURNS_RETAINED {
+    return [[PaymentRequestErrorViewController alloc] init];
+  }
+
+  PaymentRequestErrorViewController* GetPaymentRequestErrorViewController() {
+    return base::mac::ObjCCastStrict<PaymentRequestErrorViewController>(
+        controller());
+  }
+};
+
+// Tests that the correct number of items are displayed after loading the model.
+TEST_F(PaymentRequestErrorViewControllerTest, TestModel) {
+  CreateController();
+  CheckController();
+  CheckTitleWithId(IDS_IOS_PAYMENT_REQUEST_TITLE);
+
+  [GetPaymentRequestErrorViewController() loadModel];
+
+  ASSERT_EQ(1, NumberOfSections());
+  // There should be one item for the error message.
+  ASSERT_EQ(1U, static_cast<unsigned int>(NumberOfItemsInSection(0)));
+
+  // They item should be of type PriceItem.
+  id item = GetCollectionViewItem(0, 0);
+  EXPECT_TRUE([item isMemberOfClass:[PaymentsTextItem class]]);
+}