We need qucikstart-node-script

[Chamber6821]

Now, to start developing a NodeJS application on ClojureScript comfortably, you need to go through 9 circles of hell, when on other platforms it is enough to initialize the project and everything works for you.

The main pain: starting 2 parallel processes. You must first run shadow-cljs watch, which is obvious, and only after the first compilation is complete (which is actually not very obvious) run node out/script.js.

Additional pain: Conjure (a plugin for CLJS support in Neovim) does not automatically correctly connect to nREPL and you need to manually connect it with a command. The instructions are described in Conjure itself, and this resource should become part of the guide for beginners in CLJS.

I created a draft version of such a repository, which requires evaluation. I believe that my or a similar solution should be included in the organization as a quickstart-node-script repository.

[thheller]

nodemon you definitely do not need.

Hot Reload works the same as in the Browser, the :main fn only ever runs once (called init in this post). You basically need a :dev/after-load that does whatever you need to to get actuall hot-reload. nodemon does not hot-reload and instead just restarts the entire process.

Can't comment on the Conjure parts. Never used it.

[Chamber6821]

nodemon used only for manual reload JS Runtime. Manual write stop function it is not comfortable for all things. For example I write code that add listener lambda via process.stdin.on and additional stop function would complicate my code. Manual restart JS Runtime to reset JS state is more simple and relaible than stop function

[Chamber6821]

I was disable auto restart in nodemon

[thheller]

Well, constantly restarting your node process also resets the REPL every time.

You can write your code in a hot-reload friendly way, so that the function that acutally gets called on process.stdin.on is hot-reloaded but only ever attached once. But it does require extra care, so sometimes just nuking everything is easier.

[Chamber6821]

Okey. You are right. Define function aside is more simple and elegant than nodemon

[Chamber6821]

I have some throubles. I write this code

(ns index)

(defn on-input [buffer]
  (prn buffer))

(defn -main []
  (js/process.stdin.on "data" on-input))

And when I change body of on-input with hot reload from shadow I do not see changes when I input text. I think it is relaited with references inside JS

[thheller]

The -main fn uses the on-input at the time it is called. So when the event fires it uses the function from that time. It is an internal reference somewhere where shadow-cljs cannot hot reload it. The actual defn on-input is replaced, but never used again. One common way to handle this is using an intermediate function.

For example:

(ns index)

(defn on-input [buffer]
  (prn buffer))

(defn -main []
  (js/process.stdin.on "data" #(on-input %)))

This way the node internal things holds the anonymous function, which when called calls the actual on-input, which will always take the latest reference, thus works with hot-reload.

[Chamber6821]

I will add this example to README

[Chamber6821]

@thheller I remove nodemon and add usecase with handler reference