browser-host

The browser-host utility creates a browser environment for executing code. Something that you miss to test browser specific things. For example, to test fetch, AbortController and other things.

Example

write a test:

const test = require('tape');

test('equality test', function (t) {
  t.plan(1);
  t.equal(1, 1);
});

run your test in a headless browser:

$ browserify test.js | browser-host

TAP version 13
# equality test
ok 1 should be equal

1..1
# tests 1
# pass  1

# ok

Note that if you use any external modules, probably you need to bundle your test file via browserify or any other bundler first in order to run its contents in the browser environment.

Usage

$ browser-host [entry] [options]

Description:

  The browser-host utility reads file and executes its contents (javascript code)
  in the browser environment. The environment is created
  by headless chrome browser (via puppeteer). If file is a signle dash ('-')
  or absent, browser-host reads from the standard input.

Options:

  -h, --help      print usage
  -b, --browser   run Chrome / Chromium browser in non-headless mode
  --html          print resulting html only
  --mock          path to module to handle requests for mocking a dynamic back-end

Examples:

  $ echo "console.log('hello, world!')" | browser-host
  $ echo "console.log('hello, world!')" > a.js; browser-host a.js

Dynamic backend mock

Using --mock mock.js you can add a custom server-side implementation to provide a stable behavior for your requests. All paths should start from /mock.

mock.js should be a plain commonjs module and export a function that accepts req and res arguments. Note that browser-host uses a plain http module to create a server.

Example:

module.exports = function mock(req, res) {
  const pathname = req.url.split('?').shift();

  if (pathname === '/mock/weather') {
    const r = JSON.stringify({ weather: 'is ok' });

    res.writeHead(200, { 'content-type': 'application/json' });
    res.write(r);
    res.end();
    return;
  }

  res.writeHead(404, { 'content-type': 'text/plain' });
  res.write('404 not found');
  res.end();
}

Install

Install via package manager (npm or yarn):

yarn add browser-host --dev

License

MIT License

Copyright (c) 2019 Aleksey Litvinov