What do I need to do to get the blog to work in rails 4.2?

Question

I have just installed rails 4.2 . I have found this tutorial for making a quick blog: https://www.reinteractive.net/posts/32-ruby-on-rails-3-2-blog-in-15-minutes-step-by-ste

Answer 1

This should solve your problem:
Add gem 'therubyracer', '~> 0.12.1' into your gemfile (or uncomment it - should be already there...)
Then run bundle install

Hope this helps.

Answer 2

I had exactly the same ExecJS::ProgramError on Windows. The only solution that really helped was provided by KeithP here: Rails-4, ExecJS::ProgramError in Pages#welcome, i.e.,

Rollback to gem 'coffee-script-source', '1.8.0'.

Answer 3

There's some info here: ExecJS::RuntimeError in Users#index (RoR)

What I found when I looked into this problem was that in CoffeeScript there's a checkin here that I think broke things for Windows (under certain versions of the cscript runtime): https://github.com/jashkenas/coffeescript/blob/28c07d30cbd2add7ee762c7d532b2c9c972e441a/lib/coffee-script/parser.js

On line 563 it's doing an Object create(lexer) which fails with the error ActionView::Template::Error (TypeError: Object doesn't support this property or method.

Rolling back to CoffeeScript 1.8.0 (before this change) works around this problem. As others have stated in this answer and elsewhere, using a different runtime will workaround this problem too.

To roll back to CoffeeScript 1.8.0 add this to your gemfile:

gem 'coffee-script-source', '1.8.0'

And run these commands:

gem update 'coffee-script-source'
bundle update 'coffee-script-source'

Restart your server and it should be working.