CollectionViewTextItem should copy accessibilityLabel to the cell

ios/chrome/browser/ui/collection_view/cells/collection_view_text_item_unittest.mm

 // Copyright 2016 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/ui/collection_view/cells/collection_view_text_item.h"
 
 #import <CoreGraphics/CoreGraphics.h>
 #import <UIKit/UIKit.h>
 
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_text_cell.h"
 #import "ios/chrome/browser/ui/collection_view/cells/test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest_mac.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 
+// Test that accessory type is copied over to the cell from the item.
 TEST(CollectionViewTextItemTest, ConfigureCellPortsAccessoryType) {
   CollectionViewTextItem* item =
       [[CollectionViewTextItem alloc] initWithType:0];
   item.accessoryType = MDCCollectionViewCellAccessoryCheckmark;
   CollectionViewTextCell* cell = [[[item cellClass] alloc] init];
   EXPECT_TRUE([cell isMemberOfClass:[CollectionViewTextCell class]]);
   EXPECT_EQ(MDCCollectionViewCellAccessoryNone, [cell accessoryType]);
   [item configureCell:cell];
   EXPECT_EQ(MDCCollectionViewCellAccessoryCheckmark, [cell accessoryType]);
 }
 
+// Test that text properties are copied over to the cell from the item.
 TEST(CollectionViewTextItemTest, ConfigureCellPortsTextCellProperties) {
   CollectionViewTextItem* item =
       [[CollectionViewTextItem alloc] initWithType:0];
   item.text = @"some text";
   item.detailText = @"some detail text";
   CollectionViewTextCell* cell = [[[item cellClass] alloc] init];
   EXPECT_TRUE([cell isMemberOfClass:[CollectionViewTextCell class]]);
   EXPECT_FALSE([cell textLabel].text);
   EXPECT_FALSE([cell detailTextLabel].text);
   [item configureCell:cell];
   EXPECT_NSEQ(@"some text", [cell textLabel].text);
   EXPECT_NSEQ(@"some detail text", [cell detailTextLabel].text);
 }
 
+// Test that if the item has no accessibilityLabel, the cell gets one composed
+// of the text and detailText.
+TEST(CollectionViewTextItemTest, ConfigureCellDerivesAccessibilityLabel) {
+  CollectionViewTextItem* item =
+      [[CollectionViewTextItem alloc] initWithType:0];
+  item.text = @"some text";
+  item.detailText = @"some detail text";
+  CollectionViewTextCell* cell = [[[item cellClass] alloc] init];
+  EXPECT_TRUE([cell isMemberOfClass:[CollectionViewTextCell class]]);
+  EXPECT_FALSE([cell textLabel].accessibilityLabel);
+  [item configureCell:cell];
+  EXPECT_NSEQ(@"some text, some detail text", [cell accessibilityLabel]);
+}
+
+// Test that if the item has a non-empty accessibilityLabel, this is copied
+// over to the cell.
+TEST(CollectionViewTextItemTest, ConfigureCellPortsAccessibilityLabel) {
+  CollectionViewTextItem* item =
+      [[CollectionViewTextItem alloc] initWithType:0];
+  item.accessibilityLabel = @"completely different label";
+  // Also set text and detailText to verify that the derived
+  // accessibilityLabel is not composed of those.
+  item.text = @"some text";
+  item.detailText = @"some detail text";
+  CollectionViewTextCell* cell = [[[item cellClass] alloc] init];
+  EXPECT_TRUE([cell isMemberOfClass:[CollectionViewTextCell class]]);
+  EXPECT_FALSE([cell textLabel].accessibilityLabel);
+  [item configureCell:cell];
+  EXPECT_NSEQ(@"completely different label", [cell accessibilityLabel]);
+}
+
 }  // namespace