Added test namespace/task.

README.md

@@ -12,6 +12,8 @@ Leiningen is a build tool for Clojure designed to not set your hair on fire.
 
     $ lein deps # install dependencies in lib/
 
+    $ lein test [PRED] # run the project's tests, optionally filtered on PRED
+
     $ lein compile # ahead-of-time compile into classes/
 
     $ lein repl # launch a REPL with the project classpath configured

src/leiningen/test.clj

@@ -0,0 +1,27 @@
+(ns leiningen.test
+  (:refer-clojure :exclude [test])
+  (:use [clojure.test]
+        [clojure.contrib.java-utils :only [file]]
+        [clojure.contrib.find-namespaces :only [find-namespaces-in-dir]]))
+
+(defonce old-test-var test-var)
+
+(defn test-var-matching [pred var]
+  (when (pred (meta var))
+    (old-test-var var)))
+
+(defn run-matching [pred namespaces]
+  (binding [test-var (partial test-var-matching pred)]
+    (apply run-tests namespaces)))
+
+(defn test
+  "Run the projects tests. Second argument is an optional filter predicate that
+  is called with each test's metadata map."
+  [project & [pred]]
+  (let [namespaces (find-namespaces-in-dir (file (:root project) "test"))
+        runner (if pred
+                 (partial run-matching (eval pred))
+                 run-tests)]
+    (doseq [n namespaces]
+      (require n))
+    (apply runner namespaces)))