Webpacker in Rails 5 takes a long time to compile not that many files. How can I see what it's doing?

webpack ruby-on-rails-5 webpacker
cmrichards picture cmrichards · Sep 11, 2018 · Viewed 8k times · Source 
[Webpacker] Compiling…

It takes several seconds (6.2 seconds) to compile any of my changes to javascript files. It's really slowing my JS development down.

Is there any way to see what Webpacker in Rails is doing and which files it's spending most of its time on? It also be good if it could show me how much time each npm library was using.

I can manually run the rails webpacker:compile command but there doesn't seem to be any verbose mode on that.

Any help is appreciated, thanks!

Answer

cmrichards picture cmrichards · Sep 11, 2018

I should've RTFM:

If you want to use live code reloading, or you have enough JavaScript that on-demand compilation is too slow, you'll need to run ./bin/webpack-dev-server or ruby ./bin/webpack-dev-server. Windows users will need to run these commands in a terminal separate from bundle exec rails s. This process will watch for changes in the app/javascript/packs/*.js files and automatically reload the browser to match.

Running ./bin/webpack-dev-server uses live code reloading and is super fast!

Related questions

Getting Unexpected Token Export

I am trying to run some ES6 code in my project but I am getting an unexpected token export error. export class MyClass { constructor() { console.log("es6"); } }

Read More
Correct path for img on React.js

I have some problem with my images on my react project. Indeed I always thought that relative path into src attribute was built on the files architecture Here my files architecture: components file1.jsx file2.jsx file3.jsx container img …

Read More
Managing jQuery plugin dependency in webpack

I'm using Webpack in my application, in which I create two entry points - bundle.js for all my JavaScript files/codes, and vendors.js for all libraries like jQuery and React. What do I do in order to use …

Read More