Miraculously disappearing dependencies when using lein cljsbuild auto.

[art-solopov]

I'm trying to write my first ClojureScript project using NPM dependencies.

Here's my project.clj file:

(defproject cljsplay "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [
                 [org.clojure/clojure "1.8.0"]
                 [org.clojure/clojurescript "1.10.339"]
                 ]
  :plugins [[lein-cljsbuild "1.1.7"]]
  :main ^:skip-aot cljsplay.core
  :target-path "target/%s"
  :profiles {:uberjar {:aot :all}}
  :cljsbuild {
              :builds [{
                        :source-paths ["src-cljs"]
                        :compiler {
                                   :output-to "target/cljs/bundle.js"
                                   :pretty-print true
                                   :optimizations :whitespace
                                   :install-deps true
                                   :npm-deps {:moment "2.22"}
                                   }
                        }]}
  )

And here is my src-cljs/core.cljs file:

(ns cljsplay.core
  (:require [moment])
  )

(defn -getApp []
  (.getElementById js/document "app")
  )

(defn -updTime []
  (let [app (-getApp)]
    (set! (.-innerText app) (.format (moment) "YYYY-MM-DD || HH:mm:ss"))
    )
  )

(defn -main
  []
  (.setInterval js/window -updTime 100)
  )

(.addEventListener js/window "load" -main)

When I compile it with lein cljsbuild once, everything seems okay. However, when I try running lein cljsbuild auto, it loses the momentjs. I get this error:

Error: goog.require could not find: module$home$art_solopov$Projects$cljsplay$node_modules$moment$moment

And indeed, when I check the resulting bundle, there is no trace of actual moment.js library.

[leblowl]

@art-solopov I ran into something similar, except I get a different error, like invalid nameToPath or something. On first compilation, the dependency is required in cljs_deps.js. Second compilation, it's missing. I haven't tracked down where in lein-cljsbuild the error is. The code looks pretty simple, but there is also quite a bit of logic. I tested using run-compiler from this library directly (in support subproject), everything works well. I tested using the ClojureScript compiler directly, everything works well. So not sure what's going on just yet.

This isn't a fix for this exact problem, but as an alternative to Leiningen/cljs-build, you can use deps.edn and the ClojureScript compiler directly. The ClojureScript compiler appears to offer the same auto functionality as this plugin. Here is a basic example I drafted:

(require '[cljs.build.api :as cljs])
(require '[cljs.closure :as closure])
(cljs/watch (closure/compilable-input-paths ["src" "src-cljs" "env/dev/cljs"])
         {:asset-path "/js"
          :output-to    "target/cljsbuild/public/js/app.js"
          :output-dir   "target/cljsbuild/public/js"
          :main         'my.app
         
          :install-deps true
          :npm-deps {:moment "2.22"}

          :source-map   true
          :pretty-print true
          :verbose      true})

Update 2019-07-14
@art-solopov Thanks for the simple sample project, I have been using it for testing this issue.

I believe I've narrowed down the issue to the use of cljs.env/*compiler* here https://github.com/emezeske/lein-cljsbuild/blob/master/plugin/src/leiningen/cljsbuild.clj#L137... If I comment the binding, it works. I found cljs.env/*compiler* here https://github.com/clojure/clojurescript/blob/master/src/main/clojure/cljs/env.cljc

I am not very familiar with Clojurescript or lein-cljsbuild code but my guess is that the compiler depends on cljs.env/*compiler* internally and cljsbuild re-binds it to an initial value for each run of the compiler, thus messing up the compiler. The compiler env is defined here for each build: https://github.com/emezeske/lein-cljsbuild/blob/master/plugin/src/leiningen/cljsbuild.clj#L109 and then for each loop of the compiler, it looks like the same immutable compiler env is used: https://github.com/emezeske/lein-cljsbuild/blob/master/plugin/src/leiningen/cljsbuild.clj#L122 ... Maybe the compiler is expecting different state in cljs.env/*compiler*

Related initial commit:
4fb2670

Related update:
8bd20c9

These are from 5-6 years ago. It says Clojurescript was version 0.0-2197 in one commit message...
The initial commit says it was added to support incremental compilation. I thought the Clojurescript incremental compilation just works without the environment binding now.

[abradley2]

This has bit my as well. I can't quite figure out how to move of leiningen and achieve this same configuration with deps.edn