gistfile1.clj

(ns clj-demgen.plugin-test
  (:require [clj-demgen.plugin :refer :all]
            [clojure.test :refer :all]
            [immutant.dev]))

(defn can-resolve? [symbol]
  (not (nil? (resolve symbol))))

(defn can-not-resolve? [symbol]
  (not (can-resolve? symbol)))

(deftest initially-cannot-resolve-plugin-ns []
  (is (can-not-resolve? 'demgen-plugin.test-plugin.core/main)
      "Plugin main namespace cannot be resolved without loading the plugin first."))

(deftest plugin-cannot-be-loaded-without-load-plugin []
  (require 'demgen-plugin.test-plugin.core)
  (is (can-not-resolve? 'demgen-plugin.test-plugin.core/main)
      "When plugin is not loaded require does not make the main namespace availible."))

(deftest load-plugin-test []
  (load-plugin '[demgen-plugin/test-plugin "0.1.0-SNAPSHOT"]
               'demgen-plugin.test-plugin.core)
  (is (can-resolve? 'demgen-plugin.test-plugin.core/main)
      "After loading the plugin the main namespace can be resolved.")

  (unload-plugin '[demgen-plugin/test-plugin "0.1.0-SNAPSHOT"]
                 'demgen-plugin.test-plugin.core)
  (is (can-not-resolve? 'demgen-plugin.test-plugin.core/main)
      "After unloading the plugin the main namespace cannot be resolved."))

gistfile2.clj

(ns clj-demgen.plugin
  (:require [immutant.dev]
            [clojure.set :as set]))

(defn remove-dependencies!
  [& deps]
  (immutant.dev/reload-project!
   (-> (immutant.dev/current-project)
       (update-in [:dependencies] #(vec (set/difference (set %) (set deps)))))))

(defn load-plugin [coordinate main-ns]
  (immutant.dev/add-dependencies! coordinate)
  (require main-ns :reload))

(defn unload-plugin [coordinate main-ns]
  (remove-ns main-ns)
  (remove-dependencies! coordinate))