Fongo Component

A component using fongo as in-memory mock of MongoDB. Useful for unit testing Mongo-dependant components (eg. repositories). Compatible with mongo-component from system.

Installation

Add the following dependency to your project.clj file:

Usage

Require the library:

(require '[component.fongo :refer [new-fongo]
         '[com.stuartsierra.component :as component])

Starting the component will create a :db key:

(-> (new-fongo "test")
    (component/start)
    :db)

Using with repositories

An example repository protocol:

(defprotocol Repository
  (find-by-id [repo id])
  (save [repo object]))

Could be implemented with system as:

(defrecord MongoRepositoryComponent [mongo-db]
  component/Lifecycle Repository

  (start [component]
    (println ";; Starting MongoRepositoryComponent")
    component)

  (stop [component]
    (println ";; Stopping MongoRepositoryComponent"))

  (find-by-id [repo id]
    (mc/find-one-as-map (:db mongo-db) "documents" {:_id (ObjectId. id)}))

  (save [repo object]
    (mc/insert-and-return (:db mongo-db) "documents" object)))

(defn mongo-repo-component []
  (->MongoRepositoryComponent {}))

And tested with fongo-component:

(def system
  (->
    (component/system-map
       :mongo-db (new-fongo "test")
       :repo     (repository/mongo-repo-component))
    (component/system-using
       {:repo [:mongo-db]})))

(deftest mongo-repository
  (alter-var-root #'system component/start)
  (is (:repo system) "mongo repository has been added to system")
  (testing "saving and getting object"
    (let [repo (:repo system)]
      (let [saved (repository/save repo {:name "test"})]
        (is (not (nil? (:_id saved))))
        (is (= saved (repository/find-by-id repo (.toString (:_id saved))))))))
  (alter-var-root #'system component/stop)
  (is (nil? (:repo system)) "mongo repository has been removed from system"))

License

Copyright © 2014 Piotr Jagielski

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.