Add 'Testing' documentation

Signed-off-by: Greg Haskins <[email protected]>

Author: ghaskins

doc/cljdoc.edn

@@ -3,4 +3,5 @@
   ["Workflows" {:file "doc/workflows.md"}]
   ["Activities" {:file "doc/activities.md"}]
   ["Workers" {:file "doc/workers.md"}]
-  ["Client" {:file "doc/client.md"}]]}
+  ["Client" {:file "doc/client.md"}]
+  ["Testing" {:file "doc/testing.md"}]]}

doc/testing.md

@@ -0,0 +1,42 @@
+# Testing Your Workflows
+
+## Overview
+
+This Temporal Clojure SDK provides a test framework to facilitate Workflow unit-testing. The test framework includes an in-memory implementation of the Temporal service.
+
+You can use the provided environment with a Clojure unit testing framework of your choice, such as `clojure.test`.
+
+## Example
+
+```clojure
+(ns my.tests
+  (:require [clojure.test :refer :all]
+            [taoensso.timbre :as log]
+            [temporal.client.core :as c]
+            [temporal.testing.env :as e]
+            [temporal.workflow :refer [defworkflow]]
+            [temporal.activity :refer [defactivity] :as a]))
+
+(def task-queue "MyTaskQueue")
+
+(defactivity greet-activity
+  [ctx {:keys [name] :as args}]
+  (log/info "greet-activity:" args)
+  (str "Hi, " name))
+
+(defworkflow greeter-workflow
+  [ctx {:keys [args]}]
+  (log/info "greeter-workflow:" args)
+  @(a/invoke greet-activity args))
+
+(deftest my-test
+  (testing "Verifies that we can invoke our greeter workflow"
+    (let [{:keys [client] :as env} (e/create {:queue-name task-queue})
+          (c/create-workflow client greeter-workflow {:task-queue task-queue})]
+      (c/start workflow {:name "Bob"})
+      (is (= @(c/get-result workflow) "Hi, Bob")))))
+```
+
+The primary difference between this test and a real-world application is the use of ([temporal.testing.env/create](https://cljdoc.org/d/io.github.manetu/temporal-sdk/CURRENT/api/temporal.testing.env#create)) function.  This method simultaneously creates an instance of the in-memory Temporal service *and* a client already connected to this environment.
+
+Typical tests may opt to create the testing environment within a [fixture](https://clojuredocs.org/clojure.test/use-fixtures), but this is left as an exercise to the reader.  The testing environment may be cleanly shutdown with ([stop](https://cljdoc.org/d/io.github.manetu/temporal-sdk/CURRENT/api/temporal.testing.env#stop))