[Error resolution] How to resolve the error "Could not find a JavaScript runtime." After upgrading Catalina!

error contents

After upgrading from macOS Catalina 10.15.3 to 10.15.6, when I tried $ bin / rspec, the following error occurred.

terminal

$bin/rspec
/.../.../.../vendor/bundle/ruby/2.5.0/gems/execjs2.7.0/lib/execjs/runtimes.rb:58:in `autodetect': 
Could not find a JavaScript runtime. 
See https://github.com/rails/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)

I'm getting an error that the JavaScript runtime cannot be found.

environment

--macOS Catalina 10.15.6 (after version upgrade)

• ruby '2.5.7'
• rails '5.2.3'
• rspec-rails '4.0.0.beta2'

Solution

** Conclusion **: Added "gem'mini_racer', platforms :: ruby" to Gemfile

If you look at the error log, you can see the link on Github, so check the link. After checking, it seems good to add a gem called mini_racer to the Gemfile.

Gemfile

(abridgement)
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'mini_racer', platforms: :ruby
(abridgement)

Uncomment this part of the Gemfile. Then do $ bundle install and When I tried $ bin / rspec again, the test ran normally.