Allow for provision of a Testcontainer instance (#16)

* Allow for provision of a Testcontainer instance

Testcontainers provides many different container implementations that
can be very useful. This simple change allows callers to provide their
own, premade container instance so consumers can flexibly choose their
container type. If no container instance is supplied, then
clj-test-containers falls back to its original behavior.

* Extract  function

* Cleanup, ensure Clojure types instead of Java types

Co-authored-by: Tim Zöller <mail@tim-zoeller.de>

project.clj

@@ -7,7 +7,8 @@
   :dependencies [[org.clojure/clojure "1.10.1"]
                  [org.testcontainers/testcontainers "1.14.3"]]
   :plugins [[metosin/bat-test "0.4.4"]]
-  :bat-test {:report [:pretty {:type :junit 
+  :bat-test {:report [:pretty {:type :junit
                                :output-to "target/junit.xml"}]}
+  :profiles {:dev {:dependencies [[org.testcontainers/postgresql "1.14.3"]]}}
   :target-path "target/%s")
 

src/clj_test_containers/core.clj

@@ -12,23 +12,27 @@
     BindMode/READ_WRITE
     BindMode/READ_ONLY))
 
-(defn create
+(defn init
   "Sets the properties for a testcontainer instance"
-  [{:keys [image-name exposed-ports env-vars command]}]
-  (let [container (GenericContainer. image-name)]
-    (.setExposedPorts container (map int exposed-ports))
+  [{:keys [container exposed-ports env-vars command]}]
+  (.setExposedPorts container (map int exposed-ports))
 
-    (if (some? env-vars)
-      (doseq [pair env-vars]
-        (.addEnv container (first pair) (second pair))))
+  (run! (fn [[k v]] (.addEnv container k v)) env-vars)
 
-    (if (some? command)
-      (.setCommand container command))
+  (when command
+    (.setCommand container command))
 
-    {:container container
-     :exposed-ports (.getExposedPorts container)
-     :env-vars (.getEnvMap container)
-     :host (.getHost container)}))
+  {:container container
+   :exposed-ports (vec (.getExposedPorts container))
+   :env-vars (into {} (.getEnvMap container))
+   :host (.getHost container)})
+
+(defn create
+  "Creates a generic testcontainer and sets its properties"
+  [{:keys [image-name] :as options}]
+  (->> (GenericContainer. image-name)
+       (assoc options :container)
+       init))
 
 (defn create-from-docker-file
   [{:keys [exposed-ports env-vars command docker-file]

test/clj_test_containers/core_test.clj

@@ -1,9 +1,12 @@
 (ns clj-test-containers.core-test
   (:require [clojure.test :refer :all]
-            [clj-test-containers.core :refer :all]))
+            [clj-test-containers.core :refer :all])
+  (:import [org.testcontainers.containers
+            PostgreSQLContainer]))
+
+(deftest create-test
+  (testing "Testing basic testcontainer generic image initialisation"
 
-(deftest init-test
-  (testing "Testing basic testcontainer generic image initialization"
     (let [container (create {:image-name "postgres:12.2"
                              :exposed-ports [5432] 
                              :env-vars {"POSTGRES_PASSWORD" "pw"}})
@@ -30,12 +33,22 @@
 
   (testing "Executing a command in the running Docker container"
     (let [container (create {:image-name "postgres:12.2"
-                             :exposed-ports [5432] 
+                             :exposed-ports [5432]
                              :env-vars {"POSTGRES_PASSWORD" "pw"}})
           initialized-container (start! container)
           result (execute-command! initialized-container ["whoami"])
           stopped-container (stop! container)]
       (is (= 0 (:exit-code result)))
+      (is (= "root\n" (:stdout result)))))
+
+  (testing "Executing a command in the running Docker container with a custom container"
+    (let [container (init {:container (PostgreSQLContainer. "postgres:12.2")
+                           :exposed-ports [5432]
+                           :env-vars {"POSTGRES_PASSWORD" "pw"}})
+          initialized-container (start! container)
+          result (execute-command! initialized-container ["whoami"])
+          stopped-container (stop! container)]
+      (is (= 0 (:exit-code result)))
       (is (= "root\n" (:stdout result))))))
 
 (deftest init-volume-test