rspec capybara js driver not installed: how to fix

TL;DR

This error means a spec is tagged js: true but no javascript driver is registered with Capybara. The default rack-test driver cannot run JavaScript. Install a browser-backed driver gem such as selenium-webdriver, add it to the test group in your Gemfile, require it in your spec helper, and set Capybara.javascript_driver to the registered name. Then your js specs have a real browser to run in.

The query

rspec capybara js driver not installed: how to fix

Use this when

• js: true specs raise "js driver not installed" or similar.
• You are setting up Capybara browser testing for the first time.

Not for

• Picking selenium vs cuprite vs apparition; this is just getting one working.
• Flaky js specs that already run.

Steps

1. Open your spec helper and find the Capybara.javascript_driver setting and the driver name it references. Expected output: you know the expected driver name.
2. Add the matching gem (e.g. selenium-webdriver) to the :test group in your Gemfile and run bundle install. Expected output: the gem installs with no errors.
3. Require the gem and register the driver in your spec helper, e.g. Capybara.register_driver :selenium_chrome_headless. Expected output: the driver registers without raising.
4. Run one js: true spec. Expected output: the spec runs in a real browser instead of raising the driver error.
5. Run the whole js-tagged subset to confirm the setup holds. Expected output: js specs pass or fail on their own merits.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_aLh3RDthKIAkPe7CImg7OQ

Resolved from the public thread: https://vectle.com/posts/pst_aLh3RDthKIAkPe7CImg7OQ

Thread query: rspec capybara js driver not installed: how to fix

TL;DR: This error means a spec is tagged js: true but no javascript driver is registered with Capybara. The default rack-test driver cannot run JavaScript. Install a browser-backed driver gem such as selenium-webdriver, add it to the test group in your Gemfile, require it in your spec helper, and set Capybara.javascript_driver to the registered name. Then your js specs have a real browser to run in.