components/Tabs/tests/unit/MDCItemBarTests.m

// Copyright 2019-present the Material Components for iOS authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import <UIKit/UIKit.h>
#import <XCTest/XCTest.h>

#import "../../src/private/MDCItemBar.h"
#import "../../src/private/MDCItemBarStyle.h"

@interface MDCItemBar (Testing)
- (UITabBarItem *)itemAtIndexPath:(NSIndexPath *)indexPath;

// Collection view for items.
@property(nonatomic, strong, nullable) UICollectionView *collectionView;
@end

@interface MDCItemBarTests : XCTestCase

/** The item bar being tested. */
@property(nonatomic, strong) MDCItemBar *itemBar;

@end

@implementation MDCItemBarTests

- (void)setUp {
  [super setUp];

  MDCItemBarStyle *style = [[MDCItemBarStyle alloc] init];
  style.unselectedTitleFont = [UIFont systemFontOfSize:12];
  style.selectedTitleFont = [UIFont systemFontOfSize:12];
  MDCItemBar *itemBar = [[MDCItemBar alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
  [itemBar applyStyle:style];
  UITabBarItem *item1 = [[UITabBarItem alloc] initWithTitle:@"Item 1" image:nil tag:0];
  UITabBarItem *item2 = [[UITabBarItem alloc] initWithTitle:@"Item 2" image:nil tag:1];
  itemBar.items = @[ item1, item2 ];
  itemBar.selectedItem = item1;
  [itemBar layoutIfNeeded];
  self.itemBar = itemBar;
}

- (void)tearDown {
  self.itemBar = nil;

  [super tearDown];
}

- (void)testItemAtIndexPath {
  // Given
  MDCItemBar *itemBar = [[MDCItemBar alloc] init];
  UITabBarItem *item1 = [[UITabBarItem alloc] initWithTitle:@"first tab" image:nil tag:0];
  UITabBarItem *item2 = [[UITabBarItem alloc] initWithTitle:@"second tab" image:nil tag:0];

  // When
  itemBar.items = @[ item1, item2 ];

  // Then
  NSIndexPath *indexPathForFirstItem = [NSIndexPath indexPathForItem:0 inSection:0];
  XCTAssertNotNil([itemBar itemAtIndexPath:indexPathForFirstItem]);
  NSIndexPath *indexPathForSecondItem = [NSIndexPath indexPathForItem:1 inSection:0];
  XCTAssertNotNil([itemBar itemAtIndexPath:indexPathForSecondItem]);
  NSIndexPath *indexPathForThirdItem = [NSIndexPath indexPathForItem:2 inSection:0];
  XCTAssertNil([itemBar itemAtIndexPath:indexPathForThirdItem]);
  NSIndexPath *indexPathWithNonZeroSection = [NSIndexPath indexPathForItem:0 inSection:1];
  XCTAssertNil([itemBar itemAtIndexPath:indexPathWithNonZeroSection]);
  NSIndexPath *indexPathWithItemEqualToNegativeOne = [NSIndexPath indexPathForItem:-1 inSection:0];
  XCTAssertNil([itemBar itemAtIndexPath:indexPathWithItemEqualToNegativeOne]);
}

- (void)testItemBarIsNotAccessibilityElement {
  // Given
  MDCItemBar *itemBar = [[MDCItemBar alloc] init];

  // Then
  XCTAssertFalse(itemBar.isAccessibilityElement);
}

- (void)testItemBarIsAccessibilityTabBar {
  // When
  self.itemBar.accessibilityTraits = UIAccessibilityTraitLink;

  // Then
  XCTAssertEqual(self.itemBar.accessibilityTraits,
                 UIAccessibilityTraitTabBar | UIAccessibilityTraitLink);
}

- (void)testItemBarViewDoesNotIncludesTabInAccessibilityLabel {
  // When
  for (UITabBarItem *item in self.itemBar.items) {
    UIView *view = [self.itemBar accessibilityElementForItem:item];
    XCTAssertTrue([view isKindOfClass:[UIView class]]);
    if ([view isKindOfClass:[UIView class]]) {
      NSString *accessibilityLabel = ((UIView *)view).accessibilityLabel;
      XCTAssertFalse([accessibilityLabel localizedCaseInsensitiveContainsString:@"tab"],
                     @"Item bar items should not include the faked 'tab' information previously "
                     @"used for iOS 9.");
    }
  }
}

- (void)testItemBarViewUsesCustomAccessibilityLabelWhenSetAndNotTitle {
  // Given
  MDCItemBarStyle *style = [[MDCItemBarStyle alloc] init];
  style.unselectedTitleFont = [UIFont systemFontOfSize:12];
  style.selectedTitleFont = [UIFont systemFontOfSize:12];
  MDCItemBar *itemBar = [[MDCItemBar alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
  [itemBar applyStyle:style];
  UITabBarItem *item1 = [[UITabBarItem alloc] initWithTitle:@"Item 1" image:nil tag:0];
  NSString *customLabel = @"Custom label";

  // When
  item1.accessibilityLabel = customLabel;
  itemBar.items = @[ item1 ];
  itemBar.selectedItem = item1;

  // Then
  UIView *view = (UIView *)[itemBar accessibilityElementForItem:item1];
  NSString *accessibilityLabel = view.accessibilityLabel;
  XCTAssertTrue([accessibilityLabel containsString:customLabel]);
}

/**
 Verifies that @c MDCItemBar assigns a @c UIPointerInteraction to each of its cells.
 */
- (void)testItemBarAddsPointerInteractionsToCells {
#ifdef __IPHONE_13_4
  if (@available(iOS 13.4, *)) {
    NSArray *visibleCells = self.itemBar.collectionView.visibleCells;
    XCTAssertEqual(visibleCells.count, self.itemBar.items.count);
    for (NSUInteger itemIndex = 0; itemIndex < visibleCells.count; itemIndex++) {
      UICollectionViewCell *cell = visibleCells[itemIndex];
      XCTAssertEqual(cell.interactions.count, 1,
                     @"cell at index %lu should only have one UIInteraction.",
                     (unsigned long)itemIndex);
      XCTAssert([cell.interactions.firstObject isKindOfClass:[UIPointerInteraction class]],
                @"cell at index %lu should have a UIPointerInteraction.", (unsigned long)itemIndex);
    }
  }
#endif
}

@end