test: show diff when test:bin fails

package-lock.json

@@ -1394,6 +1394,23 @@
         "type-detect": "^4.0.5"
       }
     },
+    "chai-diff": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/chai-diff/-/chai-diff-1.0.1.tgz",
+      "integrity": "sha1-bGaJRwDYDNkDUKtORANiXU9TocE=",
+      "dev": true,
+      "requires": {
+        "diff": "^2.2.1"
+      },
+      "dependencies": {
+        "diff": {
+          "version": "2.2.3",
+          "resolved": "https://registry.npmjs.org/diff/-/diff-2.2.3.tgz",
+          "integrity": "sha1-YOr9DSjukG5Oj/ClLBIpUhAzv5k=",
+          "dev": true
+        }
+      }
+    },
     "chalk": {
       "version": "1.1.3",
       "resolved": "https://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",

package.json

@@ -35,6 +35,7 @@
     "babel-runtime": "^5.1.10",
     "benchmark": "~1.0",
     "chai": "^4.2.0",
+    "chai-diff": "^1.0.1",
     "concurrently": "^5.0.0",
     "dirty-chai": "^2.0.1",
     "dtslint": "^0.5.5",
@@ -84,7 +85,7 @@
   "scripts": {
     "format": "prettier --write '**/*.js' && eslint --fix .",
     "check-format": "prettier --check '**/*.js'",
-    "lint": "eslint --max-warnings 0 . ",
+    "lint": "eslint --max-warnings 0 .",
     "dtslint": "dtslint types",
     "test": "grunt",
     "extensive-tests-and-publish-to-aws": "npx mocha tasks/task-tests/ && grunt --stack extensive-tests-and-publish-to-aws",

tasks/test-bin.js

@@ -1,7 +1,10 @@
-const childProcess = require('child_process'),
+const childProcess = require('child_process');
-  fs = require('fs'),
+const fs = require('fs');
-  os = require('os'),
+const os = require('os');
-  expect = require('chai').expect;
+
+const chai = require('chai');
+chai.use(require('chai-diff'));
+const expect = chai.expect;
 
 module.exports = function(grunt) {
   grunt.registerTask('test:bin', function() {
@@ -18,7 +21,7 @@ module.exports = function(grunt) {
     const normalizedOutput = normalizeCrlf(stdout);
     const normalizedExpectedOutput = normalizeCrlf(expectedOutput);
 
-    expect(normalizedOutput).to.equal(normalizedExpectedOutput);
+    expect(normalizedOutput).not.to.be.differentFrom(normalizedExpectedOutput);
   });
 };