importmap-rails VS import-maps

With importmaps (https://github.com/rails/importmap-rails) and Hotwire (https://hotwired.dev/), you write plain js and serve it.

Also packages are served via CDN. There is no tree shaking. Rails got rid of the whole bundling step.

Importmap audit - “checks the NPM registry for known security issues”

It worked, but JS changes were not coming through. Digging into the Importmap docs (see 'sweeping the cache', it monitors changes according to the setting config.importmap.cache_sweepers. So, by adding the locations where I have my JS files, I also got JS changes passed through.

You can't use TypeScript, or anything that requires pre-compile, with importmap. answered issue

Let's begin by installing the necessary dependencies. The first gem generates the importmap object, manages caching, and helps with library installations, among other things. I recommend reading the entire readme to become familiar with its capabilities. The second gem will be discussed later, it is used to compile JSX files. Gemfile

Yeah, those were brand new right around the time I started this project a few years ago with Rails 7 (or was it 6.1?). I actually ended up removing them in favor of importmap-rails since I wanted as simple of a frontend as possible and I wasn't sure of relying on what was, at the time, a brand new way of doing frontend work. Things change so quickly in JS-land that I'm always hesitant to make something a dependency unless it has a strong track record of being continuously maintained.

source "https://rubygems.org" git_source(:github) { |repo| "https://github.com/#{repo}.git" } ruby "3.1.0" # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main" gem "rails", "~> 7.0.4", ">= 7.0.4.2" # The original asset pipeline for Rails [https://github.com/rails/sprockets-rails] gem "sprockets-rails" # Use sqlite3 as the database for Active Record gem "sqlite3", "~> 1.4" # Use the Puma web server [https://github.com/puma/puma] gem "puma", "~> 5.0" # Use JavaScript with ESM import maps [https://github.com/rails/importmap-rails] gem "importmap-rails" # Hotwire's SPA-like page accelerator [https://turbo.hotwired.dev] gem "turbo-rails" # Hotwire's modest JavaScript framework [https://stimulus.hotwired.dev] gem "stimulus-rails" # Build JSON APIs with ease [https://github.com/rails/jbuilder] gem "jbuilder" gem "mongoid" gem "mongoid-grid_fs" gem 'bootstrap', '~> 5.2.2' #sourced from https://github.com/twbs/bootstrap-rubygem gem 'rack-cors' # Windows does not include zoneinfo files, so bundle the tzinfo-data gem gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ] # Reduces boot times through caching; required in config/boot.rb gem "bootsnap", require: false

Also, installing StimulusReflex seems quite not easy for the moment: It seems there are some quirks along the way if you're using import-maps for managing javascript dependencies as I do. Embracing the Rails way at least prevents you from this sort of issue.

If you're using importmap-rails, you'll need to pin stimulus-multiselect:

Long time huge fan of JS. I appreciate your calling out the multi-paradigm aspect; having these first class functions & prototype based inheritance has been so flexible.

TC39 has done a great job shaping the language over the years. New capabilities are usually well thought out & integrate well. Async await has been amazing.

The one major miss that makes me so sad and frustrated is modules; js has gotten better everywhere except it's near requirement for build tooling. Being able to throw some scripts on a page and go is still an unparalleled experience in the world, is so direct & tactile an experience. EcmaScript Modules was supposed to improve things, help get us back, but imports using url specifiers made the whole thing non-modular, was a miss. We're still tangled & torn. Import-maps has finally fixed but it's no where near as straightforward, and it still doesn't work in workers, which leaves us infuriatingly shirt of where the past was. https://github.com/WICG/import-maps/issues/2

makes sure your app is getting the download it expects. Adoption is probably pretty minimal though. https://developer.mozilla.org/en-US/docs/Web/Security/Subres...

I think the big thing making this unlikely though is that very few folks use cdns these days. We designed ESM as a module system for the language, but then took a good fraction of a decade to build import-maps, to let us actually use modules in a modular way. Good news, we can finally use modules modularly! https://caniuse.com/import-maps

Bad news? Oh import-maps only works for the simplest case. Doesn't work in webworkers/service workers. https://github.com/WICG/import-maps/issues/2

The point is that single page apps almost always are bundled together, as using CDNs hasn't even been technically possible.

Also, CDNs are kind of somewhat pointless, now that http caches are partitioned by origin (for security reasons). They might have better anycast infrastructure to get the content out faster, but without the caching there's no inherent advantage. The user will download the same jquery file again in each site they go to, no already having it cached anymore. Bah humbug!

https://github.com/WICG/import-maps/issues/2

Bare specifiers has been the tragedy of ESM. Nice module syntax... that is utterly u deoyable & which has had to have awful de-modularizing specifiers hard-coded into each file to make it work. Abominable sin to introduce "modules" to JS/es2015 then spend a decade dragging everyone along with no story for how to have modular modules.

Import-maps are like "here" to fix this on the web... finally... except they only are shipping to the happiest sunniest easiest case, with Web Workers being totally shit out of luck in spite of some very simple straightforward suggested paths forward. https://github.com/WICG/import-maps/issues/2

I think Deno is making pretty good tradeoffs along the way here. This looks like package.json at surface level, but there is a nightmare of complexity under the surface. Typescript, ESM, cjs all have various pressures they create & in Node it's just incredibly tight & tense dealing with packaging, where-as Deno's happy path of Typescript first does not slowly tatters one over time. It really has been super pleasant being free of the previous world, and having something much more web-platform centric, more intented, with less assembly & less building, and more doing the actual coding.

I really hope import-maps eventually get broader support. Maybe this long-dwelling webworker issue should be brought up with WinterCG.

Import maps proposal

The concept of Import Maps was born in 2018 and made its long way until it was declared a new web standard implemented by Chrome in 2021 and some other browsers.

For package managers, you can use something like import maps to let the user specify which path points to what package, and resolve it properly.

Huh. I was about to complain that this breaks with web standards, but apparently it's being proposed as a standard feature: https://github.com/WICG/import-maps

Interesting!