Using Jasmine in the browser

The jasmine-browser-runner NPM module runs your Jasmine specs in a browser. It’s suitable for interactive use with normal browsers as well as running specs in CI builds using either headless Chrome or Saucelabs.

Getting started

npm install --save-dev jasmine-browser-runner jasmine-core
npx jasmine-browser-runner init

yarn add -D jasmine-browser-runner jasmine-core
npx jasmine-browser-runner init

If you intend to use ES modules, add --esm to the jasmine-browser-runner init command.

Then, customize spec/support/jasmine-browser.json to suit your needs. You can change the spec files, helpers, and source files that are loaded, specify the Jasmine env’s configuration, and more.

You can also use the --config option to specify a different file. This file can be a JSON file or a javascript file that exports a object that looks like the JSON above.

Running specs interactively

To start the server so that you can run the specs interactively (particularly useful for debugging):

npx jasmine-browser-runner serve

Then visit http://localhost:8888/ in the browser of your choice.

Run the tests on the command line

npx jasmine-browser-runner runSpecs

The specs will be run in a browser (Firefox by default). Once the run is finished, jasmine-browser-runner will exit 0 if everything passed and nonzero if any specs failed or were filtered out.

To use a browser other than Firefox, add a browser field to jasmine-browser.json:

{
  // ...
  "browser": "chrome"
}

Its value can be "internet explorer", "firefox", "safari", "MicrosoftEdge", "chrome", or "headlessChrome".

ES module support

If a source, spec, or helper file’s name ends in .mjs, it will be loaded as an ES module rather than a regular script. Note that ES modules can only be loaded from other ES modules. So if your source files are ES modules, your spec files need to be ES modules too.

To allow spec files to import source files via relative paths, set the specDir config field to something that’s high enough up to include both spec and source files, and set srcFiles to []. You can autogenerate such a configuration by running npx jasmine-browser-runner init --esm.

Import maps are also supported:

{
   // ...
   "importMap": {
     "moduleRootDir": "node_modules", 
     "imports": {
       "some-lib":"some-lib/dist/index.mjs",
       "some-lib/": "some-lib/dist/",
       "some-cdn-lib": "https://example.com/some-cdn-lib"
      }
   }
}

Use with Rails

You can use jasmine-browser-runner to test your Rails application’s JavaScript, whether you use the Asset Pipeline or Webpacker.

Webpacker

Run yarn add --dev jasmine-browser-runner.
Run npx jasmine-browser-runner init.

Edit spec/support/jasmine-browser.json as follows:

 {
   "srcDir": ".",
   "srcFiles": [],
   "specDir": "public/packs/js",
   "specFiles": [
     "specs-*.js"
   ],
   "helpers": [],
   // ...
 }

Create app/javascript/packs/specs.js (or app/javascript/packs/specs.jsx if you use JSX) as follows:

 (function() {
   'use strict';
    
   function requireAll(context) {
     context.keys().forEach(context);
   }

   requireAll(require.context('spec/javascript/helpers/', true, /\.js/));
   requireAll(require.context('spec/javascript/', true, /[sS]pec\.js/));
 })();

Add 'spec/javascript' to the additional_paths array in config/webpacker.yml.
Put your spec files in spec/javascript.

To run the specs:

Run bin/webpack --watch.
Run npx jasmine-browser-runner.
visit http://localhost:8888.

Asset Pipeline

Run yarn init if there isn’t already package.json file in the root of the Rails application.
Run yarn add --dev jasmine-browser-runner.
Run npx jasmine-browser-runner init.

Edit spec/support/jasmine-browser.json as follows:

 {
   "srcDir": "public/assets",
   "srcFiles": [
     "application-*.js"
   ],
   "specDir": "spec/javascript",
   "specFiles": [
     "**/*[sS]pec.?(m)js"
   ],
   "helpers": [
     "helpers/**/*.?(m)js"
   ],
   // ...
 }

Put your spec files in spec/javascript.

To run the specs:

Either run bundle exec rake assets:precompile or start the Rails application in an environment that’s configured to precompile assets.
Run npx jasmine-browser-runner.
Visit http://localhost:8888.

Remote Grid support (Saucelabs, BrowserStack, etc.)

jasmine-browser-runner can run your Jasmine specs on a remote grid provider like Saucelabs, BrowserStack or your own Selenium Grid. To use a remote grid hub, set the browser object in your config file as follows:

// jasmine-browser.json
{
  // ...
  // BrowserStack
  "browser": {
    "name": "safari",
    "useRemoteSeleniumGrid": true,
    "remoteSeleniumGrid": {
      "url": "https://hub-cloud.browserstack.com/wd/hub",
      "bstack:options": {
        "browserVersion": "16",
        "os": "OS X",
        "osVersion": "Monterey",
        "local": "true",
        "localIdentifier": "tunnel ID",
        "debug": "true",
        "userName": "your BrowserStack username",
        "accessKey": "your BrowserStack access key"
      }
    }
  }
}

// jasmine-browser.json
{
  // ...
  // Saucelabs
  "browser": {
    "name": "safari",
    "useRemoteSeleniumGrid": true,
    "remoteSeleniumGrid": {
      "url": "https://ondemand.saucelabs.com/wd/hub",
      "platformName": "macOS 12",
      "sauce:options": {
        "tunnel-identifier": "tunnel ID",
        "userName": "your Saucelabs username",
        "accessKey": "your Saucelabs access key"
      }
    }
  }
}

When using a remote grid provider, all properties of the browser object are optional except for name which will be passed as the browserName capability, and useRemoteSeleniumGrid which must be set to a value of true. if a remoteSeleniumGrid object is included, any values it contains, with the exception of the url will be used as capabilties sent to the grid hub url. if no value is specified for the url then a default of http://localhost:4445/wd/hub is used.

Want more control?

const path = require('path');
const jasmineBrowser = require('jasmine-browser-runner');

const config = require(path.resolve('spec/support/jasmine-browser.json'));
config.projectBaseDir = path.resolve('some/path');

jasmineBrowser.startServer(config, { port: 4321 });