Hello! Is there anyway I can set up an environment variable that is replaced at build time? For instance, I want my source code to have an IP address pointing to localhost, but when I release a build I want it to be replaced with my server's address

I use closure-defines for this kind of configuration. https://clojurescript.org/reference/compiler-options#closure-defines & goog-define https://cljs.github.io/api/cljs.core/goog-define where the second argument would be your default localhost address

☝️ Same. There's a section on how to use them in the user guide, too: https://shadow-cljs.github.io/docs/UsersGuide.html#closure-defines.

that's perfect, thanks!

I use deps.edn and aliases with a namespace containing a map with all the variables.

Hi, I’m looking to use shadow-cljs to self-host a cljs project in a web worker. I feel like I’m close and probably configuring my build wrong… In my shadow-cljs.edn config I have my cljs worker build configured like this;

{:builds {:cljs-worker {:target :browser
                        :output-dir "resources/public/js"
                        :asset-path "/js"
                        :compiler-options {:optimizations :simple}
                        :modules {:cljs-worker-base {:entries [shadow.cljs.bootstrap.env]}
                                  :cljs-worker {:init-fn workers.cljs.core/init!
                                                :depends-on #{:cljs-worker-base}
                                                :web-worker true}}}

(ns workers.cljs.core
  (:require [cljs.env :as env]
            [cljs.js :as cljs]
            [shadow.cljs.bootstrap.browser :as boot]))

(defn- process-response
  [{:keys [error value] :as result}]

  (when (some? error)
    (js/console.log "ERROR")
    (js/console.error error))

  (when (some? value)
    (js/console.log "VALUE")
    (js/console.log value))

  result)

(defonce compile-state-ref (env/default-compiler-env))

(defn evaluate [code]
  (cljs/eval-str
   compile-state-ref
   code
   nil
   {:eval cljs/js-eval
    :load (partial boot/load compile-state-ref)}
   process-response))

(defn init! []
  (boot/init compile-state-ref {:path "/js"} #(evaluate "(+ 1 1)")))

:cljs-worker
  {:target :bootstrap
   :output-dir "resources/public/js"
   :asset-path "/js"
   :compiler-options {:optimizations :simple}
   :modules {:cljs-worker-base {:entries [shadow.cljs.bootstrap.env]}
             :cljs-worker {:entries [cljs.js]
                           :exclude #{cljs.js}
                           :macros []
                           :init-fn workers.cljs.core/init!
                           :depends-on #{:cljs-worker-base}
                           :web-worker true}}}

@oconn failed to download boostrap file:/js/index.transit.json looks like you are trying to do this directly from the filesystem? that won't work, you need a http server. you can use :dev-http

:modules does nothing in :bootstrap

you need the browser build and the bootstrap build. separate.

@thheller - Looks like index.transit.json is loaded directly in shadow.cljs.bootstrap.browser/init. I’m running a dev server using;

:devtools {:http-root "resources/public"
           :http-port 9000
           :preloads [shadow.remote.runtime.cljs.browser]} 

:cljs-worker
  {:target :bootstrap
   :output-dir "resources/public/js/workers/cljs"
   :compiler-options {:optimizations :simple}
   :entries [cljs.js workers.cljs.core]
   :exclude #{cljs.js}
   :macros []}

I am running into something interesting, I have to access the :cause field of an cljs.core/ExceptionInfo and noticed it's being mangled by an release build. Now figuring out how to protect against the mangling.

https://github.com/clojure/core.async/blob/472340f947789513775d2dde5a478ea1ab03d333/src/main/clojure/cljs/core/async/interop.cljs#L13

The cause I want to read out is build here in this async.interop. Advanced compilation mangles the class name, and the cause field, making it inaccessible for ex-cause.

@oconn no. your :modules control that in your case will be cljs-worker.js in the :output-dir

you load that in the html and then bootstrap init

again failed to download boostrap file:/js/index.transit.json this error suggests that you just loaded the index.html directly from the filesystem in the browser instead of

@deplect in general if something gets mangled that you don't want mangled you need externs. see https://shadow-cljs.github.io/docs/UsersGuide.html#_simplified_externs just add cause one line to preserve it

@thheller amazing, was just writing my own extern, but this is magic. Thank you