add highlightStyle options in tests

test/compare.js

@@ -7,32 +7,27 @@ module.exports = function (gm, dir, finish, GM) {
     if (err) return finish(err);
     if (!same) return finish(new Error('Compare should be the same!'));
 
-    // Compare almost similar images for which ImageMagick
-    // returns a exponent-style floating point number
-    gm.compare(__dirname + '/fixtures/compare_1.png', __dirname + '/fixtures/compare_2.png', function(err, same, diff) {
+    // Create a new noisy image
+    gm.noise(0.3).write(dir + '/noise3.png', function (err) {
       if (err) return finish(err);
 
-      // Create a new noisy image
-      gm.noise(0.3).write(dir + '/noise3.png', function (err) {
+      var options = {
+        highlightColor: 'yellow',
+        highlightStyle: 'XOR',
+        file: dir + '/diff.png',
+        tolerance: 0.001
+      };
+
+      // Compare these images and write diff to a file.
+      GM.compare(dir + '/original.jpg', dir + '/noise3.png', options, function(err, same) {
         if (err) return finish(err);
         if (!same) return finish(new Error('Compare should be the same!'));
 
-        var options = {
-          highlightColor: 'yellow',
-          file: dir + '/diff.png',
-          tolerance: 0.001
-        };
-
-        // Compare these images and write to a file.
-        GM.compare(dir + '/original.jpg', dir + '/noise3.png', options, function(err) {
-          if (err) return finish(err);
-
-          fs.exists(options.file, function(exists) {
-            if (exists) finish();
-            else finish(new Error('Diff file does not exist.'));
-          });
+        fs.exists(options.file, function(exists) {
+          if (exists) finish();
+          else finish(new Error('Diff file does not exist.'));
         });
       });
-    });
+    })
   });
-};
+};