shadow-cljs `:esm` target with ESM dependency for node

README.md

Using the REPL build-specific

I'm using Calva with VSCode. My steps

1. watch the build

D:\projects\census\census-geojson (master -> origin) (census-geojson@2.0.0)
λ shadow-cljs watch lib

2. fire runtime in separate terminal

D:\projects\census\census-geojson (master -> origin) (census-geojson@2.0.0)
λ shadow-cljs cljs-repl lib

3. "Jack in" to Calva on VSCode

clj꞉shadow.user꞉> 
; Creating cljs repl session...
; Connecting cljs repl: shadow-cljs...
;   The Calva Connection Log might have more connection progress information.
; Connected session: cljs, repl: node-repl
; Evaluating file: tests.cljs
; SHADOW import error D:\projects\census\census-geojson\.shadow-cljs\builds\node-repl\dev\out\cljs-runtime\shadow.js.shim.module$node_fetch.js
; 
; Execution error (Error) at (<cljs repl>:1).
+ require() of ES Module D:\projects\census\census-geojson\node_modules\node-fetch\src\index.js from D:\projects\census\census-geojson\[stdin] not supported.
+ Instead change the require of index.js in D:\projects\census\census-geojson\[stdin] to a dynamic import() which is available in all CommonJS modules.
:repl/exception!
cljs꞉test.utils.tests꞉> 
; nREPL Connection was closed

package.json

{
  "name": "census-geojson",
  "version": "2.0.0",
  "description": "Convenience functions for working with Census APIs: Statistics, Cartographic GeoJSON, lat/lng -> FIPS, and other niceties.",
  "scripts": {
    "build": "shadow-cljs release lib"
  },
  "type": "module",
  "repository": {
    "type": "git",
    "url": "git+https://github.com/loganpowell/census-geojson.git"
  },
  "keywords": [
    "geojson",
    "census",
    "shapefiles",
    "boundaries",
    "government",
    "usa",
    "cartography"
  ],
  "author": "Logan Powell",
  "license": "MIT",
  "bugs": {
    "url": "https://github.com/loganpowell/census-geojson/issues"
  },
  "homepage": "https://github.com/loganpowell/census-geojson#readme",
  "dependencies": {
    "node-fetch": "^3.2.10",
    "xmlhttprequest": "^1.8.0",
    "xregexp": "^5.1.1"
  }
}

shadow-cljs.edn

{:source-paths ["src"]
 :dependencies [[cljs-ajax "0.8.4"]
                [funcool/cuerdas "2022.06.16-403"]
                [clojusc/defun "0.4.0"]
                [lambdaisland/fetch "1.1.60"]
                [frankiesardo/linked "1.3.0"]
                [net.cgrand/xforms "0.19.2"]]
 :nrepl        {:port 3333}
 :builds       {:lib {:target           :esm
                      :output-dir       "public/census"
                      :modules {:census {:exports {default census.core/census}}}
                      :js-options {:keep-as-import #{"node-fetch"}}
                      :compiler-options {:optimizations :simple}}}}

utils.core.cljc

(ns census.utils.core
  (:require
   [ajax.core           :refer [GET]]
   [lambdaisland.fetch  :as fetch]
   ["node-fetch"        :as node-fetch]
   [clojure.walk         :refer [keywordize-keys]]))
   
 ;; trying to patch fetch when user in Node environment
 (def isNode #? (:cljs (and (exists? js/process)
                         (exists? js/process.versions)
                         (exists? js/process.versions.node))
              :clj false))


 (when isNode (set! js/fetch node-fetch))