Add test for animated WebP image array

The image array used for +[UIImage animatedImageWithImages:] should share the same size.

Tests/Tests/UIImageMultiFormatTests.m

@@ -22,12 +22,41 @@
 
 @implementation UIImageMultiFormatTests
 
-- (void)testImageOrientationFromImageDataWithInvalidData {
+- (void)test01ImageOrientationFromImageDataWithInvalidData {
     // sync download image
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wundeclared-selector"
     SEL selector = @selector(sd_imageOrientationFromImageData:);
+#pragma clang diagnostic pop
     
-    UIImageOrientation orientation = [[UIImage class] performSelector:selector withObject:nil];
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
+    UIImageOrientation orientation = (UIImageOrientation)[[UIImage class] performSelector:selector withObject:nil];
+#pragma clang diagnostic pop
     expect(orientation).to.equal(UIImageOrientationUp);
 }
 
+- (void)test02AnimatedWebPImageArrayWithEqualSizeAndScale {
+    NSURL *webpURL = [NSURL URLWithString:@"https://isparta.github.io/compare-webp/image/gif_webp/webp/2.webp"];
+    NSData *data = [NSData dataWithContentsOfURL:webpURL];
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wundeclared-selector"
+    SEL selector = @selector(sd_imageWithWebPData:);
+#pragma clang diagnostic pop
+    
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
+    UIImage *animatedImage = [[UIImage class] performSelector:selector withObject:data];
+#pragma clang diagnostic pop
+    CGSize imageSize = animatedImage.size;
+    CGFloat imageScale = animatedImage.scale;
+    [animatedImage.images enumerateObjectsUsingBlock:^(UIImage * _Nonnull image, NSUInteger idx, BOOL * _Nonnull stop) {
+        CGSize size = image.size;
+        CGFloat scale = image.scale;
+        expect(imageSize.width).to.equal(size.width);
+        expect(imageSize.height).to.equal(size.height);
+        expect(imageScale).to.equal(scale);
+    }];
+}
+
 @end