Upstream Chrome on iOS source code [4/11].

ios/chrome/browser/ui/collection_view/collection_view_controller_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/collection_view_controller.h"
+
+#include "base/ios/weak_nsobject.h"
+#import "base/mac/scoped_nsobject.h"
+#import "ios/chrome/browser/ui/collection_view/cells/collection_view_item.h"
+#import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
+#import "ios/chrome/test/base/scoped_block_swizzler.h"
+#include "ios/chrome/test/block_cleanup_test.h"
+#import "ios/third_party/material_components_ios/src/components/CollectionCells/src/MaterialCollectionCells.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Checks that key methods are called.
+// CollectionViewItem can't easily be mocked via OCMock as one of the methods to
+// mock returns a Class type.
+@interface MockCollectionViewItem : CollectionViewItem
+@property(nonatomic, assign) BOOL configureCellCalled;
+@end
+
+@implementation MockCollectionViewItem
+
+@synthesize configureCellCalled = _configureCellCalled;
+
+- (void)configureCell:(MDCCollectionViewCell*)cell {
+  self.configureCellCalled = YES;
+  [super configureCell:cell];
+}
+
+@end
+
+namespace {
+
+typedef NS_ENUM(NSInteger, SectionIdentifier) {
+  SectionIdentifierFoo = kSectionIdentifierEnumZero,
+};
+
+typedef NS_ENUM(NSInteger, ItemType) {
+  ItemTypeFooBar = kItemTypeEnumZero,
+  ItemTypeFooBiz,
+};
+
+class CollectionViewControllerTest : public BlockCleanupTest {};
+
+}  // namespace
+
+TEST_F(CollectionViewControllerTest, InitDefaultStyle) {
+  base::scoped_nsobject<CollectionViewController> controller(
+      [[CollectionViewController alloc]
+          initWithStyle:CollectionViewControllerStyleDefault]);
+  EXPECT_EQ(nil, controller.get().appBar);
+}
+
+TEST_F(CollectionViewControllerTest, InitAppBarStyle) {
+  base::scoped_nsobject<CollectionViewController> controller(
+      [[CollectionViewController alloc]
+          initWithStyle:CollectionViewControllerStyleAppBar]);
+  EXPECT_NE(nil, controller.get().appBar);
+}
+
+TEST_F(CollectionViewControllerTest, CellForItemAtIndexPath) {
+  base::scoped_nsobject<CollectionViewController> controller(
+      [[CollectionViewController alloc]
+          initWithStyle:CollectionViewControllerStyleDefault]);
+  [controller loadModel];
+
+  [[controller collectionViewModel]
+      addSectionWithIdentifier:SectionIdentifierFoo];
+  base::scoped_nsobject<MockCollectionViewItem> someItem(
+      [[MockCollectionViewItem alloc] initWithType:ItemTypeFooBar]);
+  [[controller collectionViewModel] addItem:someItem
+                    toSectionWithIdentifier:SectionIdentifierFoo];
+
+  ASSERT_EQ(NO, [someItem configureCellCalled]);
+  [controller collectionView:[controller collectionView]
+      cellForItemAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0]];
+  EXPECT_EQ(YES, [someItem configureCellCalled]);
+}
+
+TEST_F(CollectionViewControllerTest, ReconfigureCells) {
+  base::scoped_nsobject<CollectionViewController> controller(
+      [[CollectionViewController alloc]
+          initWithStyle:CollectionViewControllerStyleDefault]);
+  [controller loadModel];
+
+  CollectionViewModel* model = [controller collectionViewModel];
+  [model addSectionWithIdentifier:SectionIdentifierFoo];
+
+  base::scoped_nsobject<MockCollectionViewItem> firstReconfiguredItem(
+      [[MockCollectionViewItem alloc] initWithType:ItemTypeFooBar]);
+  [model addItem:firstReconfiguredItem
+      toSectionWithIdentifier:SectionIdentifierFoo];
+
+  base::scoped_nsobject<MockCollectionViewItem> secondReconfiguredItem(
+      [[MockCollectionViewItem alloc] initWithType:ItemTypeFooBiz]);
+  [model addItem:secondReconfiguredItem
+      toSectionWithIdentifier:SectionIdentifierFoo];
+
+  base::scoped_nsobject<MockCollectionViewItem> firstNonReconfiguredItem(
+      [[MockCollectionViewItem alloc] initWithType:ItemTypeFooBiz]);
+  [model addItem:firstNonReconfiguredItem
+      toSectionWithIdentifier:SectionIdentifierFoo];
+
+  base::scoped_nsobject<MockCollectionViewItem> thirdReconfiguredItem(
+      [[MockCollectionViewItem alloc] initWithType:ItemTypeFooBiz]);
+  [model addItem:thirdReconfiguredItem
+      toSectionWithIdentifier:SectionIdentifierFoo];
+
+  base::scoped_nsobject<MockCollectionViewItem> secondNonReconfiguredItem(
+      [[MockCollectionViewItem alloc] initWithType:ItemTypeFooBiz]);
+  [model addItem:secondNonReconfiguredItem
+      toSectionWithIdentifier:SectionIdentifierFoo];
+
+  // The collection view is not visible on screen, so it has not created any of
+  // its cells.  Swizzle |cellsForItemAtIndexPath:| and inject an implementation
+  // for testing that always returns a non-nil cell.
+  base::scoped_nsobject<MDCCollectionViewCell> dummyCell(
+      [[MDCCollectionViewCell alloc] init]);
+  {
+    ScopedBlockSwizzler swizzler([UICollectionView class],
+                                 @selector(cellForItemAtIndexPath:),
+                                 ^(id self) {
+                                   return dummyCell.get();
+                                 });
+
+    NSArray* itemsToReconfigure = @[
+      firstReconfiguredItem, secondReconfiguredItem, thirdReconfiguredItem
+    ];
+    [controller reconfigureCellsForItems:itemsToReconfigure
+                 inSectionWithIdentifier:SectionIdentifierFoo];
+  }
+
+  EXPECT_TRUE([firstReconfiguredItem configureCellCalled]);
+  EXPECT_TRUE([secondReconfiguredItem configureCellCalled]);
+  EXPECT_TRUE([thirdReconfiguredItem configureCellCalled]);
+
+  EXPECT_FALSE([firstNonReconfiguredItem configureCellCalled]);
+  EXPECT_FALSE([secondNonReconfiguredItem configureCellCalled]);
+}