Don't run pixelmatch if image dims don't match

Author: camdecoster

test/image/compare_pixels_test.js

@@ -126,15 +126,22 @@ for (let mockName of allMockList) {
 
     const img0 = PNG.sync.read(fs.readFileSync(base));
     const img1 = PNG.sync.read(fs.readFileSync(test));
+    let dimensionMismatch = false;
     for (const key of ['height', 'width']) {
         const length0 = img0[key];
         const length1 = img1[key];
         if (length0 !== length1) {
             console.error(key + 's do not match: ' + length0 + ' vs ' + length1);
-            failed.add(mockName);
+            dimensionMismatch = true;
         }
     }
 
+    if (dimensionMismatch) {
+        fs.copyFileSync(test, diff);
+        failed.add(mockName);
+        continue;
+    }
+
     if (virtualWebgl) {
         if (flakyListVirtualWebgl.has(mockName)) threshold = 0.7;
         else threshold = Math.max(0.4, threshold);