ActionView::Template::Error (ReferenceError: Map is not defined)

Actual behavior

while try to update react-rails from 1.5 to 2.3.4, it seems there is a big change, i’ve no idea how to fix these problems. I don’t think i am the only person.

System configuration

Sprockets or Webpacker version: i just don’t know how to check this React-Rails version: 2.3.4 Rect_UJS version: i just don’t know how to check this Rails version: 5.1.4 Ruby version: ruby 2.3.3p222 (2016-11-21 revision 56859) [x86_64-linux] Since I user docker-compose, Dockerfile: FROM rails:onbuild

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1. upgrade rails to 5.1.4
2. upgrade react-rails to 2.3.4
3. bundle install
4. modify the application.rb as you mentioned
5. rails g react:install
6. add prerender: true to my componet
7. restart my docker container, then get error:
8. below is the debug result by web-console,maybe some help:

[p-salido]

@oiahoon I had this issue, resolved it by adding babel-polyfill.

Step 1: download https://npm-cdn.herokuapp.com/babel-polyfill@6.26.0/dist/polyfill.min.js (per https://babeljs.io/docs/usage/polyfill/), put it in vendor/assets/javascripts

Step 2: add to application.js or something like vendor/assets/javascripts/vendor.js if you have it:

//= require babel-polyfill.min

[BookOfGreg]

You don’t have to only use ES6, we prefer ES6 to ES5 but in general ES5 is more compatible with things.

Now I think about it, if you’re using therubyracer as the JS runtime, you may need to swap to mini_racer as mini_racer uses a newer version of Chrome’s LibV8 which may enable ES6 features such as Map.

We dropped therubyracer support a few versions back.