Automate tests using Headless Chrome + Karma runner

.travis.yml

@@ -1,9 +1,16 @@
+sudo: true
+
 language: node_js
 node_js:
-  - "8.11.3"
-before_install: npm install -g grunt-cli
+  - "lts/*"
+
+# Setup headless Chrome support
+# https://docs.travis-ci.com/user/gui-and-headless-browsers/#Using-the-Chrome-addon-in-the-headless-mode
+addons:
+  chrome: stable
+before_install:
+  - google-chrome-stable --headless --disable-gpu --remote-debugging-port=9222 http://localhost &
+
 notifications:
   email: false
   irc: "irc.mozilla.org#filer"
-env:
-  - "FILER_UPSTREAM_URI=\"default\" FILER_UPSTREAM_BRANCH=\"default\" FILER_UPSTREAM_REMOTE_NAME=\"default\""

CONTRIBUTING.md

@@ -17,10 +17,13 @@ npm install
 
 You can now run the following `npm` scripts:
 
-* `npm test` will build Filer and the tests in `tests/` and start a web server at http://localhost:1234 where you can run the tests.
-* `npm lint` will run `eslint` on the `src` and `tests` directories.
+* `npm run lint` will run `eslint` on the `src` and `tests` directories.
+* `npm run test:manual` will build the tests, and allow you to run them in a browser manually by loading http://localhost:1234.
+* `npm run karma-mocha` will build Filer and the tests, and finally run the tests in a headless Chrome browser.
+* `npm test` will run `lint` followed by `karma-chrome`, and is what we do on Travis.
 * `npm run build` will bundle two versions of Filer: `dist/filer.js` (unminified) and `dist/filer.min.js` (minified) as well as source map files.
 
+
 Once you've done some hacking and you'd like to have your work merged, you'll need to
 make a pull request. If you're patch includes code, make sure to check that all the
 unit tests pass, including any new tests you wrote. Finally, make sure you add yourself

karma.conf.js

@@ -0,0 +1,18 @@
+module.exports = function(config) {
+  config.set({
+    browsers: ['ChromeHeadless'],
+    singleRun: true,
+    basePath: '',
+    files: ['tests/dist/index.js'],
+
+    frameworks: ['mocha', 'chai'],
+    reporters: ['mocha'],
+    client: {
+      mocha: {
+        ui: 'bdd',
+        timeout: 5000,
+        slow: 250
+      }
+    }
+  });
+};

package.json

@@ -18,9 +18,13 @@
   "license": "BSD-2-Clause",
   "scripts": {
     "lint": "eslint src tests",
-    "test": "parcel tests/index.html --out-dir tests/dist",
+    "test:manual": "parcel tests/index.html --out-dir tests/dist",
+    "pretest": "npm run lint",
+    "test": "npm run travis",
     "prebuild": "parcel build --global Filer src/index.js --no-minify --out-file filer.js",
-    "build": "parcel build --global Filer src/index.js --out-file filer.min.js --detailed-report"
+    "build": "parcel build --global Filer src/index.js --out-file filer.min.js --detailed-report",
+    "prekarma-mocha": "parcel build tests/index.js --out-dir tests/dist",
+    "karma-mocha": "karma start karma.conf.js"
   },
   "repository": {
     "type": "git",
@@ -33,6 +37,11 @@
   "devDependencies": {
     "chai": "^4.1.2",
     "eslint": "^5.0.1",
+    "karma": "^2.0.4",
+    "karma-chai": "^0.1.0",
+    "karma-chrome-launcher": "^2.2.0",
+    "karma-mocha": "^1.3.0",
+    "karma-mocha-reporter": "^2.2.5",
     "mocha": "^5.2.0",
     "parcel-bundler": "^1.9.6"
   },