Complete the 8 tests for all image transform methods, well done

Tests/Tests/SDCategoriesTests.m

@@ -15,9 +15,12 @@
 #import <SDWebImage/UIImage+MultiFormat.h>
 #import <SDWebImage/UIImage+GIF.h>
 #import <SDWebImage/UIImage+WebP.h>
+#import <SDWebImage/UIImage+Transform.h>
 
 @interface SDCategoriesTests : SDTestCase
 
+@property (nonatomic, strong) UIImage *testImage;
+
 @end
 
 @implementation SDCategoriesTests
@@ -65,8 +68,98 @@
     expect(image).notTo.beNil();
 }
 
+// UIImage+Transform test is hard to write because it's more about visual effect. Current it's tied to the `TestImage.png`, please keep that image or write new test with new image
+- (void)test05UIImageTransformResize {
+    CGSize size = CGSizeMake(200, 100);
+    UIImage *resizedImage = [self.testImage sd_resizedImageWithSize:size scaleMode:SDImageScaleModeFill];
+    expect(CGSizeEqualToSize(resizedImage.size, size)).beTruthy();
+}
+
+- (void)test06UIImageTransformCrop {
+    CGRect rect = CGRectMake(50, 50, 200, 200);
+    UIImage *croppedImage = [self.testImage sd_croppedImageWithRect:rect];
+    expect(CGSizeEqualToSize(croppedImage.size, CGSizeMake(200, 200))).beTruthy();
+    UIColor *startColor = [croppedImage sd_colorAtPoint:CGPointZero];
+    expect([startColor.sd_hexString isEqualToString:@"0x00000000"]).beTruthy();
+}
+
+- (void)test07UIImageTransformRoundedCorner {
+    CGFloat radius = 50;
+    UIRectCorner corners = UIRectCornerAllCorners;
+    CGFloat borderWidth = 1;
+    UIColor *borderCoder = [UIColor blackColor];
+    UIImage *roundedCornerImage = [self.testImage sd_roundedCornerImageWithRadius:radius corners:corners borderWidth:borderWidth borderColor:borderCoder];
+    expect(CGSizeEqualToSize(roundedCornerImage.size, CGSizeMake(300, 300))).beTruthy();
+    UIColor *startColor = [roundedCornerImage sd_colorAtPoint:CGPointZero];
+    expect([startColor.sd_hexString isEqualToString:@"0x00000000"]).beTruthy();
+    // Check the left center pixel, should be border :)
+    UIColor *checkBorderColor = [roundedCornerImage sd_colorAtPoint:CGPointMake(1, 150)];
+    expect([checkBorderColor.sd_hexString isEqualToString:borderCoder.sd_hexString]).beTruthy();
+}
+
+- (void)test08UIImageTransformRotate {
+    CGFloat angle = M_PI_4;
+    UIImage *rotatedImage = [self.testImage sd_rotatedImageWithAngle:angle fitSize:NO];
+    // Not fit size and no change
+    expect(CGSizeEqualToSize(rotatedImage.size, self.testImage.size)).beTruthy();
+    // Fit size, may change size
+    rotatedImage = [self.testImage sd_rotatedImageWithAngle:angle fitSize:YES];
+    CGSize rotatedSize = CGSizeMake(floor(300 * 1.414), floor(300 * 1.414)); // 45º, square length * sqrt(2)
+    expect(CGSizeEqualToSize(rotatedImage.size, rotatedSize)).beTruthy();
+    rotatedImage = [self.testImage sd_rotatedImageWithAngle:angle fitSize:NO];
+}
+
+- (void)test09UIImageTransformFlip {
+    BOOL horizontal = YES;
+    BOOL vertical = YES;
+    UIImage *flippedImage = [self.testImage sd_flippedImageWithHorizontal:horizontal vertical:vertical];
+    expect(CGSizeEqualToSize(flippedImage.size, self.testImage.size)).beTruthy();
+}
+
+- (void)test10UIImageTransformTint {
+    UIColor *tintColor = [UIColor blackColor];
+    UIImage *tintedImage = [self.testImage sd_tintedImageWithColor:tintColor];
+    expect(CGSizeEqualToSize(tintedImage.size, self.testImage.size)).beTruthy();
+    // Check center color, should keep clear
+    UIColor *centerColor = [tintedImage sd_colorAtPoint:CGPointMake(150, 150)];
+    expect([centerColor.sd_hexString isEqualToString:@"0x00000000"]);
+    // Check left color, should be tinted
+    UIColor *leftColor = [tintedImage sd_colorAtPoint:CGPointMake(80, 150)];
+    expect([leftColor.sd_hexString isEqualToString:tintColor.sd_hexString]);
+}
+
+- (void)test11UIImageTransformBlur {
+    CGFloat radius = 50;
+    UIImage *blurredImage = [self.testImage sd_blurredImageWithRadius:radius];
+    expect(CGSizeEqualToSize(blurredImage.size, self.testImage.size)).beTruthy();
+    // Check left color, should be blurred
+    UIColor *leftColor = [blurredImage sd_colorAtPoint:CGPointMake(80, 150)];
+    // Hard-code from the output
+    UIColor *expectedColor = [UIColor colorWithRed:0.431373 green:0.101961 blue:0.0901961 alpha:0.729412];
+    expect([leftColor.sd_hexString isEqualToString:expectedColor.sd_hexString]);
+}
+
+- (void)test12UIImageTransformFilter {
+    // Invert color filter
+    CIFilter *filter = [CIFilter filterWithName:@"CIColorInvert"];
+    UIImage *filteredImage = [self.testImage sd_filteredImageWithFilter:filter];
+    expect(CGSizeEqualToSize(filteredImage.size, self.testImage.size)).beTruthy();
+    // Check left color, should be inverted
+    UIColor *leftColor = [filteredImage sd_colorAtPoint:CGPointMake(80, 150)];
+    // Hard-code from the output
+    UIColor *expectedColor = [UIColor colorWithRed:0.85098 green:0.992157 blue:0.992157 alpha:1];
+    expect([leftColor.sd_hexString isEqualToString:expectedColor.sd_hexString]);
+}
+
 #pragma mark - Helper
 
+- (UIImage *)testImage {
+    if (!_testImage) {
+        _testImage = [UIImage imageWithContentsOfFile:[self testPNGPath]];
+    }
+    return _testImage;
+}
+
 - (NSString *)testJPEGPath {
     NSBundle *testBundle = [NSBundle bundleForClass:[self class]];
     return [testBundle pathForResource:@"TestImage" ofType:@"jpg"];
@@ -82,4 +175,9 @@
     return [testBundle pathForResource:@"TestImageStatic" ofType:@"webp"];
 }
 
+- (NSString *)testPNGPath {
+    NSBundle *testBundle = [NSBundle bundleForClass:[self class]];
+    return [testBundle pathForResource:@"TestImage" ofType:@"png"];
+}
+
 @end