simonbo

simonbo

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

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  Your Yarn packages are out of date!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

Most Liked

noelrappin

noelrappin

Author of Modern Front-End Development for Rails

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.

Where Next?

Popular Pragmatic Bookshelf topics Top

johnp
Running the examples in chapter 5 c under pytest 5.4.1 causes an AttributeError: ‘module’ object has no attribute ‘config’. In particula...
New
telemachus
Python Testing With Pytest - Chapter 2, warnings for “unregistered custom marks” While running the smoke tests in Chapter 2, I get these...
New
mikecargal
Title: Hands-On Rust (Chapter 11: prefab) Just played a couple of amulet-less games. With a bit of debugging, I believe that your can_p...
New
adamwoolhether
When trying to generate the protobuf .go file, I receive this error: Unknown flag: --go_opt libprotoc 3.12.3 MacOS 11.3.1 Googling ...
New
AndyDavis3416
@noelrappin Running the webpack dev server, I receive the following warning: ERROR in tsconfig.json TS18003: No inputs were found in c...
New
jskubick
I’m under the impression that when the reader gets to page 136 (“View Data with the Database Inspector”), the code SHOULD be able to buil...
New
New
oaklandgit
Hi, I completed chapter 6 but am getting the following error when running: thread 'main' panicked at 'Failed to load texture: IoError(O...
New
jonmac
The allprojects block listed on page 245 produces the following error when syncing gradle: “org.gradle.api.GradleScriptException: A prob...
New
creminology
Skimming ahead, much of the following is explained in Chapter 3, but new readers (like me!) will hit a roadblock in Chapter 2 with their ...
New

Other popular topics Top

AstonJ
Or looking forward to? :nerd_face:
498 13326 269
New
brentjanderson
Bought the Moonlander mechanical keyboard. Cherry Brown MX switches. Arms and wrists have been hurting enough that it’s time I did someth...
New
Rainer
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
New
PragmaticBookshelf
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
AstonJ
If you are experiencing Rails console using 100% CPU on your dev machine, then updating your development and test gems might fix the issu...
New
PragmaticBookshelf
Author Spotlight Jamis Buck @jamis This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
New
NewsBot
Node.js v22.14.0 has been released. Link: Release 2025-02-11, Version 22.14.0 'Jod' (LTS), @aduh95 · nodejs/node · GitHub
New
RobertRichards
Hair Salon Games for Girls Fun Girls Hair Saloon game is mainly developed for kids. This game allows users to select virtual avatars to ...
New
mindriot
Ok, well here are some thoughts and opinions on some of the ergonomic keyboards I have, I guess like mini review of each that I use enoug...
New

Sub Categories: