Image Diff based testing

package.json

@@ -29,6 +29,7 @@
   "devDependencies": {
     "browserify": "13.0.0",
     "buffer": "~5.0.2",
+    "data-uri-to-buffer": "^2.0.0",
     "get-pixels": "~3.3.0",
     "grunt": "^0.4.5",
     "grunt-browserify": "^5.0.0",
@@ -38,6 +39,7 @@
     "image-filter-core": "~1.0.0",
     "image-filter-threshold": "~1.0.0",
     "imagemagick": "^0.1.3",
+    "looks-same": "^3.2.1",
     "matchdep": "^0.3.0",
     "plotly.js": "~1.21.2",
     "save-pixels": "~2.3.4",

test/image-manip.js

@@ -1,6 +1,8 @@
 'use strict';
 
 var test = require('tape');
+var looksSame = require('looks-same');
+var DataURItoBuffer = require('data-uri-to-buffer');
 
 // We should only test headless code here.
 // http://stackoverflow.com/questions/21358015/error-jquery-requires-a-window-with-a-document#25622933
@@ -23,13 +25,27 @@ test("Preload", function(t) {
 });
 
 test("Inverted image isn't identical", function (t) {
-  t.notEqual(sequencer.images.image1.steps[1].output.src, sequencer.images.image1.steps[2].output.src);
-  t.end();
+  var step1 = sequencer.images.image1.steps[1].output.src;
+  var step2 = sequencer.images.image1.steps[2].output.src;
+  step1 = DataURItoBuffer(step1);
+  step2 = DataURItoBuffer(step2);
+  looksSame(step1,step2,function(err,res){
+    if(err) console.log(err);
+    t.equal(res,false);
+    t.end();
+  });
 });
 
 test("Twice inverted image is identical to original image", function (t) {
-  t.equal(sequencer.images.image1.steps[1].output.src, sequencer.images.image1.steps[3].output.src);
-  t.end();
+  var step1 = sequencer.images.image1.steps[1].output.src;
+  var step3 = sequencer.images.image1.steps[3].output.src;
+  step1 = DataURItoBuffer(step1);
+  step3 = DataURItoBuffer(step3);
+  looksSame(step1,step3,function(err,res){
+    if(err) console.log(err);
+    t.equal(res,true);
+    t.end();
+  });
 });
 
 test("PixelManipulation works for PNG images", function (t) {