main.cljs

(ns can-i-stub.main
  (:require [cljs.nodejs :as nodejs]
            [cljs.spec.alpha :as s]
            [clojure.spec.test.alpha :as stest]))

(nodejs/enable-util-print!)

(defn add2 [a b] 10.1)

(s/fdef add2 :args (s/cat :a int? :b int?) :ret int?)

(defn -main [& args]
  (println ::a (add2 1 2))
  (stest/instrument `add2 {:stub #{`add2}})
  (println ::b (add2 1 2))
  (stest/unstrument `add2)
  (println ::c (add2 1 2)))

(set! *main-cli-fn* -main)

node.clj

(require 'cljs.build.api)

(cljs.build.api/build
  "src"
  {:main      'can-i-stub.main
   :output-to "main.js"
   :target    :nodejs})

project.clj

(defproject can-i-stub "0.1.0-SNAPSHOT"
  :description "FIXME: write this!"
  :url "http://example.com/FIXME"
  :dependencies [[org.clojure/clojure "1.9.0-beta3"]
                 [org.clojure/clojurescript "1.9.946"]
                 [org.clojure/test.check "0.9.0"]]
  :jvm-opts ^:replace ["-Xmx1g" "-server"]
  :plugins [[lein-npm "0.6.2"]]
  :npm {:dependencies [[source-map-support "0.4.0"]]}
  :source-paths ["src" "target/classes"]
  :clean-targets ["out" "release"]
  :target-path "target")