diff --git a/package.json b/package.json
index f6daacc..065e249 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "main": "main.js",
   "scripts": {
     "start": "electron .",
+    "test": "jest",
     "build": "webpack",
     "package": "electron-packager .  --platform=darwin --arch=x64 --out=packaged --icon=img/out.icns --overwrite",
     "zip": "cd packaged/Alchemy-darwin-x64/ ; zip -r ../Alchemy.zip * ; cd .."
@@ -13,6 +14,7 @@
     "babel-loader": "^6.2.10",
     "babel-preset-es2015": "^6.18.0",
     "babel-preset-react": "^6.16.0",
+    "chai": "^3.5.0",
     "css-loader": "^0.26.1",
     "electron-packager": "^8.5.0",
     "eslint": "^3.13.1",
@@ -21,6 +23,7 @@
     "eslint-plugin-jsx-a11y": "^3.0.2",
     "eslint-plugin-react": "^6.9.0",
     "extract-text-webpack-plugin": "^1.0.1",
+    "jest": "^19.0.2",
     "node-sass": "^4.3.0",
     "sass-loader": "^4.1.1",
     "style-loader": "^0.13.1",
diff --git a/src/helpers/util.js b/src/helpers/util.js
index 2c46c25..9d1ad3a 100644
--- a/src/helpers/util.js
+++ b/src/helpers/util.js
@@ -17,13 +17,11 @@ const uniqueFiles = (files, newArray) =>
     })
   }, files)
 
-const removeByKey = (myObj, deleteKey) =>
-  Object.keys(myObj)
-    .filter(key => key !== deleteKey)
-    .reduce((result, current) => {
-      result[current] = myObj[current]
-      return result
-    }, {})
+const removeByKey = (myObj, deleteKey) => {
+  const newObj = Object.assign({}, myObj)
+  delete newObj[deleteKey]
+  return newObj
+}
 
 module.exports = {
   concatFiles,
diff --git a/test/util.test.js b/test/util.test.js
new file mode 100644
index 0000000..1eaf52a
--- /dev/null
+++ b/test/util.test.js
@@ -0,0 +1,99 @@
+/* global describe, it */
+/* eslint-disable prefer-arrow-callback */
+
+const { expect } = require('chai')
+const { concatFiles, uniqueFiles, removeByKey, replaceSpaceCharacters } = require('../src/helpers/util')
+
+describe('UTIL', function () {
+  describe('concatFiles()', function () {
+    it('concats files', () => {
+      const files = [
+        '/User/test/test.png',
+        '/User/test/test.jpg',
+      ]
+      expect(concatFiles(files)).to.equal('test_test')
+    })
+    it('truncates long file names', () => {
+      const files = [
+        '/User/test/testaaaaaaaaaaaaaaaaaa.png',
+        '/User/test/test.jpg',
+      ]
+      expect(concatFiles(files)).to.equal('testaaaaaa_test')
+    })
+    it('truncates final output name', () => {
+      const files = [
+        '/User/test/testaaaaaaaaaaaaaaaaaa.png',
+        '/User/test/testaaaaaaaaaaaaaaaaaa.png',
+        '/User/test/testaaaaaaaaaaaaaaaaaa.png',
+        '/User/test/testaaaaaaaaaaaaaaaaaa.png',
+        '/User/test/testaaaaaaaaaaaaaaaaaa.png',
+        '/User/test/testaaaaaaaaaaaaaaaaaa.png',
+      ]
+      expect(concatFiles(files)).to.equal('testaaaaaa_testaaaaaa_testaaaaaa_testaaaaaa_testaa')
+    })
+  })
+
+  describe('removeByKey()', function () {
+    it('remove key from an object', () => {
+      const obj = {
+        key1: 'here',
+        key2: 'there'
+      }
+      expect(removeByKey(obj, 'key1')).to.deep.equal({
+        key2: 'there'
+      })
+    })
+
+    it('do nothing if key doesnt exist', () => {
+      const obj = {
+        key1: 'here',
+        key2: 'there'
+      }
+      expect(removeByKey(obj, 'key3')).to.deep.equal({
+        key1: 'here',
+        key2: 'there'
+      })
+    })
+
+
+    it('do nothing if key doesnt exist', () => {
+      const value = 8
+      const obj = {
+        key1: value
+      }
+      expect(removeByKey(obj, 'key1')).to.deep.equal({})
+      expect(value).to.equal(8)
+    })
+  })
+
+  describe('replaceSpaceCharacters()', function () {
+    it('replace space characters with escaped space', () => {
+      const fileName = 'This is a bad file name.png'
+      expect(replaceSpaceCharacters(fileName)).to.equal('This\\ is\\ a\\ bad\\ file\\ name.png')
+    })
+  })
+
+  describe('uniqueFiles()', function () {
+    it('ensures unique files by path', () => {
+      const files = {
+        key1: 'here',
+        key2: 'there'
+      }
+      const newFiles = [
+        {
+          path: 'key1'
+        },
+        {
+          path: 'key3'
+        }
+      ]
+      expect(uniqueFiles(files, newFiles)).to.deep.equal({
+        key1: 'here',
+        key2: 'there',
+        key3: {
+          path: 'key3'
+        }
+      })
+    })
+  })
+})