Unit tests for batch fetching

AsyncDisplayKitTests/ASBatchFetchingTests.m

@@ -0,0 +1,102 @@
+/* Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <XCTest/XCTest.h>
+
+#import "ASBatchFetching.h"
+
+@interface ASBatchFetchingTests : XCTestCase
+
+@end
+
+@implementation ASBatchFetchingTests
+
+#define PASSING_RECT (CGRect){0,0,1,1}
+#define PASSING_SIZE (CGSize){1,1}
+#define PASSING_POINT (CGPoint){1,1}
+#define VERTICAL_RECT(h) (CGRect){0,0,0,h}
+#define VERTICAL_SIZE(h) (CGSize){0,h}
+#define VERTICAL_OFFSET(y) (CGPoint){0,y}
+#define HORIZONTAL_RECT(w) (CGRect){0,0,w,0}
+#define HORIZONTAL_SIZE(w) (CGSize){w,0}
+#define HORIZONTAL_OFFSET(x) (CGPoint){x,0}
+
+- (void)testBatchNullState {
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionUp, CGRectZero, CGSizeZero, CGPointZero, 0.0);
+  XCTAssert(shouldFetch == NO, @"Should not fetch in the null state");
+}
+
+- (void)testBatchAlreadyFetching {
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  [context beginBatchFetching];
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionUp, PASSING_RECT, PASSING_SIZE, PASSING_POINT, 1.0);
+  XCTAssert(shouldFetch == NO, @"Should not fetch when context is already fetching");
+}
+
+- (void)testUnsupportedScrollDirections {
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  BOOL fetchRight = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionRight, PASSING_RECT, PASSING_SIZE, PASSING_POINT, 1.0);
+  XCTAssert(fetchRight == NO, @"Should not fetch for scrolling right");
+  BOOL fetchDown = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionDown, PASSING_RECT, PASSING_SIZE, PASSING_POINT, 1.0);
+  XCTAssert(fetchDown == NO, @"Should not fetch for scrolling down");
+  BOOL fetchUp = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionUp, PASSING_RECT, PASSING_SIZE, PASSING_POINT, 1.0);
+  XCTAssert(fetchUp == YES, @"Should fetch for scrolling up");
+  BOOL fetchLeft = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionLeft, PASSING_RECT, PASSING_SIZE, PASSING_POINT, 1.0);
+  XCTAssert(fetchLeft == YES, @"Should fetch for scrolling left");
+}
+
+- (void)testVerticalScrollToExactLeading {
+  CGFloat screen = 1.0;
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  // scroll to 1-screen top offset, height is 1 screen, so bottom is 1 screen away from end of content
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionUp, VERTICAL_RECT(screen), VERTICAL_SIZE(screen * 3.0), VERTICAL_OFFSET(screen * 1.0), 1.0);
+  XCTAssert(shouldFetch == YES, @"Fetch should begin when vertically scrolling to exactly 1 leading screen away");
+}
+
+- (void)testVerticalScrollToLessThanLeading {
+  CGFloat screen = 1.0;
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  // 3 screens of content, scroll only 1/2 of one screen
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionUp, VERTICAL_RECT(screen), VERTICAL_SIZE(screen * 3.0), VERTICAL_OFFSET(screen * 0.5), 1.0);
+  XCTAssert(shouldFetch == NO, @"Fetch should not begin when vertically scrolling less than the leading distance away");
+}
+
+- (void)testVerticalScrollingPastContentSize {
+  CGFloat screen = 1.0;
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  // 3 screens of content, top offset to 3-screens, height 1 screen, so its 1 screen past the leading
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionUp, VERTICAL_RECT(screen), VERTICAL_SIZE(screen * 3.0), VERTICAL_OFFSET(screen * 3.0), 1.0);
+  XCTAssert(shouldFetch == YES, @"Fetch should begin when vertically scrolling past the content size");
+}
+
+- (void)testHorizontalScrollToExactLeading {
+  CGFloat screen = 1.0;
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  // scroll to 1-screen left offset, width is 1 screen, so right is 1 screen away from end of content
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionLeft, HORIZONTAL_RECT(screen), HORIZONTAL_SIZE(screen * 3.0), HORIZONTAL_OFFSET(screen * 1.0), 1.0);
+  XCTAssert(shouldFetch == YES, @"Fetch should begin when horizontally scrolling to exactly 1 leading screen away");
+}
+
+- (void)testHorizontalScrollToLessThanLeading {
+  CGFloat screen = 1.0;
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  // 3 screens of content, scroll only 1/2 of one screen
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionRight, HORIZONTAL_RECT(screen), HORIZONTAL_SIZE(screen * 3.0), HORIZONTAL_OFFSET(screen * 0.5), 1.0);
+  XCTAssert(shouldFetch == NO, @"Fetch should not begin when horizontally scrolling less than the leading distance away");
+}
+
+- (void)testHorizontalScrollingPastContentSize {
+  CGFloat screen = 1.0;
+  ASBatchContext *context = [[ASBatchContext alloc] init];
+  // 3 screens of content, left offset to 3-screens, width 1 screen, so its 1 screen past the leading
+  BOOL shouldFetch = ASDisplayShouldFetchBatchForContext(context, ASScrollDirectionUp, HORIZONTAL_RECT(screen), HORIZONTAL_SIZE(screen * 3.0), HORIZONTAL_OFFSET(screen * 3.0), 1.0);
+  XCTAssert(shouldFetch == YES, @"Fetch should begin when vertically scrolling past the content size");
+}
+
+@end