diff --git a/.idea/dictionaries/develar.xml b/.idea/dictionaries/develar.xml
index 3b093d007b0..d3ffc1cc326 100644
--- a/.idea/dictionaries/develar.xml
+++ b/.idea/dictionaries/develar.xml
@@ -14,6 +14,7 @@
       <w>coroutine</w>
       <w>crypto</w>
       <w>debian</w>
+      <w>difflet</w>
       <w>disturl</w>
       <w>dpkg</w>
       <w>ebusy</w>
diff --git a/.travis.yml b/.travis.yml
index 8b51253261c..bd52b5f5bab 100755
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,7 @@ os:
   - linux
   - osx
 
-osx_image: xcode7
+osx_image: xcode7.3
 
 dist: trusty
 sudo: required
diff --git a/package.json b/package.json
index 45af010adbe..72561493070 100644
--- a/package.json
+++ b/package.json
@@ -98,8 +98,9 @@
     "babel-plugin-transform-es2015-parameters": "^6.9.0",
     "babel-plugin-transform-es2015-spread": "^6.8.0",
     "decompress-zip": "^0.3.0",
+    "diff": "^2.2.3",
     "electron-download": "^2.1.2",
-    "json-parse-helpfulerror": "^1.0.3",
+    "json8": "^0.9.0",
     "path-sort": "^0.1.0",
     "plist": "^1.2.0",
     "pre-git": "^3.8.4",
diff --git a/src/metadata.ts b/src/metadata.ts
index 80c61611c3f..a2aa9e5c951 100755
--- a/src/metadata.ts
+++ b/src/metadata.ts
@@ -360,6 +360,10 @@ export class Platform {
     return this.name
   }
 
+  toJSON() {
+    return this.name
+  }
+
   public createTarget(type?: string | null, arch: Arch = archFromString(process.arch)): Map<Platform, Map<Arch, Array<string>>> {
     return new Map([[this, new Map([[arch, type == null ? [] : [type]]])]])
   }
diff --git a/test/src/BuildTest.ts b/test/src/BuildTest.ts
index 4c66e5e242a..6fa9a0d378d 100755
--- a/test/src/BuildTest.ts
+++ b/test/src/BuildTest.ts
@@ -13,7 +13,7 @@ import { createYargs } from "out/cliOptions"
 //noinspection JSUnusedLocalSymbols
 const __awaiter = require("out/awaiter")
 
-test("cli", (t) => {
+test("cli", () => {
   const yargs = createYargs()
 
   const base = {
@@ -28,14 +28,14 @@ test("cli", (t) => {
     return normalizeOptions(yargs.parse(input.split(" ")))
   }
 
-  t.deepEqual(parse("--osx"), expected({targets: Platform.OSX.createTarget()}))
-  t.deepEqual(parse("--linux"), expected({targets: Platform.LINUX.createTarget()}))
-  t.deepEqual(parse("--win"), expected({targets: Platform.WINDOWS.createTarget()}))
-  t.deepEqual(parse("-owl"), expected({targets: createTargets([Platform.OSX, Platform.WINDOWS, Platform.LINUX])}))
-  t.deepEqual(parse("-l tar.gz:ia32"), expected({targets: Platform.LINUX.createTarget("tar.gz", Arch.ia32)}))
-  t.deepEqual(parse("-l tar.gz:x64"), expected({targets: Platform.LINUX.createTarget("tar.gz", Arch.x64)}))
-  t.deepEqual(parse("-l tar.gz"), expected({targets: Platform.LINUX.createTarget("tar.gz", archFromString(process.arch))}))
-  t.deepEqual(parse("-w tar.gz:x64"), expected({targets: Platform.WINDOWS.createTarget("tar.gz", Arch.x64)}))
+  assertThat(parse("--osx")).isEqualTo(expected({targets: Platform.OSX.createTarget()}))
+  assertThat(parse("--linux")).isEqualTo(expected({targets: Platform.LINUX.createTarget()}))
+  assertThat(parse("--win")).isEqualTo(expected({targets: Platform.WINDOWS.createTarget()}))
+  assertThat(parse("-owl")).isEqualTo(expected({targets: createTargets([Platform.OSX, Platform.WINDOWS, Platform.LINUX])}))
+  assertThat(parse("-l tar.gz:ia32")).isEqualTo(expected({targets: Platform.LINUX.createTarget("tar.gz", Arch.ia32)}))
+  assertThat(parse("-l tar.gz:x64")).isEqualTo(expected({targets: Platform.LINUX.createTarget("tar.gz", Arch.x64)}))
+  assertThat(parse("-l tar.gz")).isEqualTo(expected({targets: Platform.LINUX.createTarget("tar.gz", archFromString(process.arch))}))
+  assertThat(parse("-w tar.gz:x64")).isEqualTo(expected({targets: Platform.WINDOWS.createTarget("tar.gz", Arch.x64)}))
 })
 
 test("custom buildResources dir", () => assertPack("test-app-one", allPlatforms(), {
diff --git a/test/src/helpers/fileAssert.ts b/test/src/helpers/fileAssert.ts
index 73de032fa20..8f19e26f580 100644
--- a/test/src/helpers/fileAssert.ts
+++ b/test/src/helpers/fileAssert.ts
@@ -1,39 +1,68 @@
 import { stat } from "fs-extra-p"
+import * as json8 from "json8"
+import { green, red, gray } from "chalk"
+import { diffJson } from "diff"
+import { AssertionError } from "assert"
 
 //noinspection JSUnusedLocalSymbols
 const __awaiter = require("out/awaiter")
 
 // http://joel-costigliola.github.io/assertj/
-export function assertThat(path: string) {
-  return new FileAssertions(path)
+export function assertThat(actual: any): Assertions {
+  return new Assertions(actual)
 }
 
-class FileAssertions {
-  constructor (private path: string) {
+function jsonReplacer(key: any, value: any): any {
+  if (value instanceof Map) {
+    return [...value]
+  }
+  return value === undefined ? undefined : value
+}
+
+class Assertions {
+  constructor (private actual: any) {
+  }
+
+  isEqualTo(expected: any) {
+    if (!json8.equal(this.actual, expected)) {
+      throw new AssertionError({
+        message: prettyDiff(JSON.parse(JSON.stringify(this.actual, jsonReplacer)), JSON.parse(JSON.stringify(expected, jsonReplacer)))
+      })
+    }
   }
 
   async isFile() {
-    const info = await stat(this.path)
+    const info = await stat(this.actual)
     if (!info.isFile()) {
-      throw new Error(`Path ${this.path} is not a file`)
+      throw new Error(`Path ${this.actual} is not a file`)
     }
   }
 
   async isDirectory() {
-    const info = await stat(this.path)
+    const info = await stat(this.actual)
     if (!info.isDirectory()) {
-      throw new Error(`Path ${this.path} is not a directory`)
+      throw new Error(`Path ${this.actual} is not a directory`)
     }
   }
 
   async doesNotExist() {
     try {
-      await stat(this.path)
+      await stat(this.actual)
     }
     catch (e) {
       return
     }
 
-    throw new Error(`Path ${this.path} must not exist`)
+    throw new Error(`Path ${this.actual} must not exist`)
   }
+}
+
+function prettyDiff(actual: any, expected: any): string {
+  const diffJson2 = diffJson(expected, actual)
+  const diff = diffJson2.map(part => {
+    if (part.added) return green(part.value.replace(/.+/g, '    - $&'))
+    if (part.removed) return red(part.value.replace(/.+/g, '    + $&'))
+    return gray(part.value.replace(/.+/g, '    | $&'))
+  }).join('')
+  return `\n${diff}\n`
 }
\ No newline at end of file
diff --git a/test/tsconfig.json b/test/tsconfig.json
index fadb37a5762..f0380c64e98 100755
--- a/test/tsconfig.json
+++ b/test/tsconfig.json
@@ -48,7 +48,8 @@
     "../typings/signcode.d.ts",
     "../typings/yargs.d.ts",
     "typings/decompress-zip.d.ts",
-    "typings/json-parse-helpfulerror.d.ts",
+    "typings/diff.d.ts",
+    "typings/json8.d.ts",
     "typings/path-sort.d.ts",
     "typings/plist.d.ts",
     "typings/should.d.ts",
diff --git a/test/typings/diff.d.ts b/test/typings/diff.d.ts
new file mode 100644
index 00000000000..d0027ea50a6
--- /dev/null
+++ b/test/typings/diff.d.ts
@@ -0,0 +1,69 @@
+// Generated by typings
+// Source: https://raw.githubusercontent.com/typed-typings/npm-diff/9b748f41b48c9ddcca5c2a135edd57df25d578cd/lib/index.d.ts
+declare module '~diff/lib/index' {
+// Type definitions for diff
+// Project: https://github.com/kpdecker/jsdiff
+// Definitions by: vvakame <https://github.com/vvakame/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+module JsDiff {
+  interface IDiffResult {
+    value: string;
+    added?: boolean;
+    removed?: boolean;
+  }
+
+  interface IBestPath {
+    newPos: number;
+    componenets: IDiffResult[];
+  }
+
+  class Diff {
+    ignoreWhitespace:boolean;
+
+    constructor(ignoreWhitespace?:boolean);
+
+    diff(oldString:string, newString:string):IDiffResult[];
+
+    pushComponent(components:IDiffResult[], value:string, added:boolean, removed:boolean):void;
+
+    extractCommon(basePath:IBestPath, newString:string, oldString:string, diagonalPath:number):number;
+
+    equals(left:string, right:string):boolean;
+
+    join(left:string, right:string):string;
+
+    tokenize(value:string):any; // return types are string or string[]
+  }
+
+  function diffChars(oldStr:string, newStr:string):IDiffResult[];
+
+  function diffWords(oldStr:string, newStr:string):IDiffResult[];
+
+  function diffWordsWithSpace(oldStr:string, newStr:string):IDiffResult[];
+
+  function diffJson(oldObj: Object, newObj: Object): IDiffResult[];
+
+  function diffLines(oldStr:string, newStr:string):IDiffResult[];
+
+  function diffCss(oldStr:string, newStr:string):IDiffResult[];
+
+  function createPatch(fileName:string, oldStr:string, newStr:string, oldHeader:string, newHeader:string):string;
+
+  function applyPatch(oldStr:string, uniDiff:string):string;
+
+  function convertChangesToXML(changes:IDiffResult[]):string;
+
+  function convertChangesToDMP(changes:IDiffResult[]):{0: number; 1:string;}[];
+}
+
+export = JsDiff;
+}
+declare module 'diff/lib/index' {
+import alias = require('~diff/lib/index');
+export = alias;
+}
+declare module 'diff' {
+import alias = require('~diff/lib/index');
+export = alias;
+}
diff --git a/test/typings/json-parse-helpfulerror.d.ts b/test/typings/json-parse-helpfulerror.d.ts
deleted file mode 100644
index 773f1cf7152..00000000000
--- a/test/typings/json-parse-helpfulerror.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-declare module "json-parse-helpfulerror" {
-  export function parse(data: string): any
-}
\ No newline at end of file
diff --git a/test/typings/json8.d.ts b/test/typings/json8.d.ts
new file mode 100644
index 00000000000..458fca7c29d
--- /dev/null
+++ b/test/typings/json8.d.ts
@@ -0,0 +1,4 @@
+declare module "json8" {
+  export function equal(a: any, b: any): boolean
+  export function serialize(value: any, options?: any): string
+}
\ No newline at end of file