Modern Front-End Development for Rails - Webpacker and Unexpected token errors

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1

Hello,

While trying to run the code examples from the book I always encounter the same issues that seem to be caused, maybe among other potential suspects, by webpacker.

I mostly get Unexpected token errors when webpacker tries to compile. It seems that Typescript isn’t well parsed.

By following some of the instructions described in webpacker’s README I managed sometimes before the use of Stimulus and React in the book to make it works. However once both frameworks present, I did not find my way through all those errors, to be honest.

So at this point, I can’t move forward in the book it became quite a struggle to fix here and there potential versions conflicts.

Would not it be interesting to freeze the versions of some gems/library in the Gemfile and the package.json?

Also before trying to run anything in a project directory, yarn always asks to proceed to do an integrity check, a bundle exec rails whatever can’t be run until it’s done. I don’t know if it can also play in upgrading automatically the versions that aren’t locked and thus maybe cause some issues later on.

error Couldn't find an integrity file                                                                                                     
error Found 1 errors.                                                                                                                     


========================================
  Your Yarn packages are out of date!
  Please run `yarn install --check-files` to update.
========================================


To disable this check, please change `check_yarn_integrity`
to `false` in your webpacker config file (config/webpacker.yml).


yarn check v1.22.4
info Visit https://yarnpkg.com/en/docs/cli/check for documentation about this command.

Thanks for the help, I really enjoy the book and would love to move forward through the practical aspect. :slight_smile:

Simon

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2

So, there are some versioning issues here. My plan has been to wait until the book goes final to lock the versions in the source code – it makes it easier for me to keep up while the book is in progress.

There are issues with Webpacker 5.1 and the Stimulus controllers (see https://github.com/stimulusjs/stimulus/issues/303), and I haven’t incorporated that fix into the book yet, so I’d try fixing Webpacker to ~5.0 and see if that helps.

2 Likes