Add some snapshot tests for ASTextNode2 truncation modes. (#1296)

* Add some snapshot tests for ASTextNode2 truncation modes

* Allow some tolerance in snapshots

* Express tolerance percentage correctly

* Code review comments: Move class methods up, combine declaration&initializaiton lines

* Give png files clearer names

* Oops

Tests/ASSnapshotTestCase.h

@@ -26,6 +26,9 @@ NSOrderedSet *ASSnapshotTestCaseDefaultSuffixes(void);
 #define ASSnapshotVerifyView(view__, identifier__) \
 	FBSnapshotVerifyViewWithOptions(view__, identifier__, ASSnapshotTestCaseDefaultSuffixes(), 0);
 
+#define ASSnapshotVerifyViewWithTolerance(view__, identifier__, tolerance__) \
+    FBSnapshotVerifyLayerWithOptions(view__, identifier__, ASSnapshotTestCaseDefaultSuffixes(), tolerance__);
+
 @interface ASSnapshotTestCase : FBSnapshotTestCase
 
 /**

Tests/ASTextNode2SnapshotTests.mm

@@ -15,6 +15,86 @@ @interface ASTextNode2SnapshotTests : ASSnapshotTestCase
 
 @end
 
+@interface LineBreakConfig : NSObject
+
+@property (nonatomic, assign) NSUInteger numberOfLines;
+@property (nonatomic, assign) NSLineBreakMode lineBreakMode;
+
++ (NSArray<LineBreakConfig *> *)configs;
+
+- (instancetype)initWithNumberOfLines:(NSUInteger)numberOfLines lineBreakMode:(NSLineBreakMode)lineBreakMode;
+- (NSString *)breakModeDescription;
+
+@end
+
+@implementation LineBreakConfig
+
++ (NSArray<LineBreakConfig *> *)configs
+{
+  static dispatch_once_t init_predicate;
+  static NSArray<LineBreakConfig *> *allConfigs = nil;
+
+  dispatch_once(&init_predicate, ^{
+    NSMutableArray *setup = [NSMutableArray new];
+    for (int i = 0; i <= 3; i++) {
+      for (int j = NSLineBreakByWordWrapping; j <= NSLineBreakByTruncatingMiddle; j++) {
+        if (j == NSLineBreakByClipping) continue;
+        [setup addObject:[[LineBreakConfig alloc] initWithNumberOfLines:i lineBreakMode:(NSLineBreakMode) j]];
+      }
+
+      allConfigs = [NSArray arrayWithArray:setup];
+    }
+  });
+  return allConfigs;
+}
+
+- (instancetype)initWithNumberOfLines:(NSUInteger)numberOfLines lineBreakMode:(NSLineBreakMode)lineBreakMode
+{
+  self = [super init];
+  if (self != nil) {
+    _numberOfLines = numberOfLines;
+    _lineBreakMode = lineBreakMode;
+
+    return self;
+  }
+  return nil;
+}
+
+- (NSString *)breakModeDescription {
+  NSString *lineBreak = nil;
+  switch (self.lineBreakMode) {
+    case NSLineBreakByTruncatingHead:
+      lineBreak = @"NSLineBreakByTruncatingHead";
+          break;
+    case NSLineBreakByCharWrapping:
+      lineBreak = @"NSLineBreakByCharWrapping";
+          break;
+    case NSLineBreakByClipping:
+      lineBreak = @"NSLineBreakByClipping";
+          break;
+    case NSLineBreakByWordWrapping:
+      lineBreak = @"NSLineBreakByWordWrapping";
+          break;
+    case NSLineBreakByTruncatingTail:
+      lineBreak = @"NSLineBreakByTruncatingTail";
+          break;
+    case NSLineBreakByTruncatingMiddle:
+      lineBreak = @"NSLineBreakByTruncatingMiddle";
+          break;
+    default:
+      lineBreak = @"Unknown?";
+          break;
+  }
+  return lineBreak;
+}
+
+- (NSString *)description
+{
+  return [NSString stringWithFormat:@"numberOfLines: %lu\nlineBreakMode: %@", (unsigned long) self.numberOfLines, [self breakModeDescription]];
+}
+
+@end
+
 @implementation ASTextNode2SnapshotTests
 
 - (void)setUp
@@ -45,13 +125,86 @@ - (void)testTextContainerInset_ASTextNode2
   // trivial test case to ensure ASSnapshotTestCase works
   ASTextNode *textNode = [[ASTextNode alloc] init];
   textNode.attributedText = [[NSAttributedString alloc] initWithString:@"judar"
-                                                            attributes:@{NSFontAttributeName : [UIFont italicSystemFontOfSize:24]}];
+                                                        attributes:@{NSFontAttributeName: [UIFont italicSystemFontOfSize:24]}];
   textNode.textContainerInset = UIEdgeInsetsMake(0, 2, 0, 2);
   ASDisplayNodeSizeToFitSizeRange(textNode, ASSizeRangeMake(CGSizeZero, CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX)));
 
   ASSnapshotVerifyNode(textNode, nil);
 }
 
+- (void)testTextTruncationModes_ASTextNode2
+{
+  UIView *container = [[UIView alloc] initWithFrame:(CGRect) {CGPointZero, (CGSize) {375.0f, 667.0f}}];
+
+  UILabel *textNodeLabel = [[UILabel alloc] init];
+  UILabel *uiLabelLabel = [[UILabel alloc] init];
+  UILabel *description = [[UILabel alloc] init];
+  textNodeLabel.text = @"ASTextNode2:";
+  textNodeLabel.font = [UIFont boldSystemFontOfSize:16.0];
+  textNodeLabel.textColor = [UIColor colorWithRed:0.0 green:0.7 blue:0.0 alpha:1.0];
+  uiLabelLabel.text = @"UILabel:";
+  uiLabelLabel.font = [UIFont boldSystemFontOfSize:16.0];
+  uiLabelLabel.textColor = [UIColor colorWithRed:0.0 green:0.7 blue:0.0 alpha:1.0];
+
+  description.text = @"<Description>";
+  description.font = [UIFont italicSystemFontOfSize:16.0];
+  description.numberOfLines = 0;
+
+  uiLabelLabel.textColor = [UIColor colorWithRed:0.0 green:0.7 blue:0.0 alpha:1.0];
+
+  UILabel *reference = [[UILabel alloc] init];
+  ASTextNode *textNode = [[ASTextNode alloc] init]; // ASTextNode2
+
+  NSMutableAttributedString *refString = [[NSMutableAttributedString alloc] initWithString:@"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua."
+          attributes:@{ NSFontAttributeName : [UIFont systemFontOfSize:18.0f] }];
+  NSMutableAttributedString *asString = [refString mutableCopy];
+
+  reference.attributedText = refString;
+  textNode.attributedText = asString;
+
+  CGSize size = (CGSize) {container.bounds.size.width, 120.0};
+  CGPoint origin = (CGPoint) {CGRectGetWidth(container.bounds) / 2 - size.width / 2, CGRectGetHeight(container.bounds) / 2 - size.height / 2}; // center
+
+  textNode.frame = (CGRect) {origin, size};
+  reference.frame = CGRectOffset(textNode.frame, 0, -160.0f);
+
+  textNodeLabel.bounds = (CGRect) {CGPointZero, (CGSize) {container.bounds.size.width, textNodeLabel.font.lineHeight}};
+  origin = (CGPoint) {textNode.frame.origin.x, textNode.frame.origin.y - textNodeLabel.bounds.size.height};
+  textNodeLabel.frame = (CGRect) {origin, textNodeLabel.bounds.size};
+
+  uiLabelLabel.bounds = (CGRect) {CGPointZero, (CGSize) {container.bounds.size.width, uiLabelLabel.font.lineHeight}};
+  origin = (CGPoint) {reference.frame.origin.x, reference.frame.origin.y - uiLabelLabel.bounds.size.height};
+  uiLabelLabel.frame = (CGRect) {origin, uiLabelLabel.bounds.size};
+
+  uiLabelLabel.bounds = (CGRect) {CGPointZero, (CGSize) {container.bounds.size.width, uiLabelLabel.font.lineHeight}};
+  origin = (CGPoint) {textNode.frame.origin.x, textNode.frame.origin.y - uiLabelLabel.bounds.size.height};
+  uiLabelLabel.frame = (CGRect) {origin, uiLabelLabel.bounds.size};
+
+  uiLabelLabel.bounds = (CGRect) {CGPointZero, (CGSize) {container.bounds.size.width, uiLabelLabel.font.lineHeight}};
+  origin = (CGPoint) {reference.frame.origin.x, reference.frame.origin.y - uiLabelLabel.bounds.size.height};
+  uiLabelLabel.frame = (CGRect) {origin, uiLabelLabel.bounds.size};
+
+  description.bounds = textNode.bounds;
+  description.frame = (CGRect) {(CGPoint) {0, container.bounds.size.height * 0.8}, description.bounds.size};
+
+  [container addSubview:reference];
+  [container addSubview:textNode.view];
+  [container addSubview:textNodeLabel];
+  [container addSubview:uiLabelLabel];
+  [container addSubview:description];
+
+  NSArray<LineBreakConfig *> *c = [LineBreakConfig configs];
+  for (LineBreakConfig *config in c) {
+    reference.lineBreakMode = textNode.truncationMode = config.lineBreakMode;
+    reference.numberOfLines = textNode.maximumNumberOfLines = config.numberOfLines;
+    description.text = config.description;
+    [container setNeedsLayout];
+    NSString *identifier = [NSString stringWithFormat:@"%@_%luLines", [config breakModeDescription], (unsigned long)config.numberOfLines];
+    [ASSnapshotTestCase hackilySynchronouslyRecursivelyRenderNode:textNode];
+    ASSnapshotVerifyViewWithTolerance(container, identifier, 0.01);
+  }
+}
+
 - (void)testTextContainerInsetIsIncludedWithSmallerConstrainedSize_ASTextNode2
 {
   UIView *backgroundView = [[UIView alloc] initWithFrame:CGRectZero];