From 62cb9dd516eb1f194ccf2a3268908c7ba549fc78 Mon Sep 17 00:00:00 2001
From: anatoly <tolitius@gmail.com>
Date: Mon, 28 Nov 2016 11:30:38 -0500
Subject: [PATCH] #69: stop accepts collections of states

vs. an implicit all and varargs
---
 src/mount/core.cljc                      | 18 ++++++++++++------
 test/core/mount/test/composable_fns.cljc | 12 +++++++++++-
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/src/mount/core.cljc b/src/mount/core.cljc
index c53701c..0545103 100644
--- a/src/mount/core.cljc
+++ b/src/mount/core.cljc
@@ -244,7 +244,7 @@
 (defn start [& states]
   (let [fs (-> states first)]
     (if (coll? fs)
-      (if-not (empty? fs)                ;; (mount/start) vs. (mount/start #{}) vs. (mount/start #{1 2 3})
+      (if-not (empty? fs)                      ;; (mount/start) vs. (mount/start #{}) vs. (mount/start #{1 2 3})
         (apply start fs)
         {:started #{}})
       (let [states (or (seq states)
@@ -252,11 +252,17 @@
         {:started (bring states up <)}))))
 
 (defn stop [& states]
-  (let [states (or states (find-all-states))
-        _ (dorun (map unsub states))     ;; unmark substitutions marked by "start-with"
-        stopped (bring states down >)]
-    (dorun (map rollback! states))       ;; restore to origin from "start-with"
-    {:stopped stopped}))
+  (let [fs (-> states first)]
+    (if (coll? fs)
+      (if-not (empty? fs)                      ;; (mount/start) vs. (mount/start #{}) vs. (mount/start #{1 2 3})
+        (apply stop fs)
+        {:stopped #{}})
+      (let [states (or (seq states)
+                       (find-all-states))
+            _ (dorun (map unsub states))       ;; unmark substitutions marked by "start-with"
+            stopped (bring states down >)]
+        (dorun (map rollback! states))         ;; restore to origin from "start-with"
+        {:stopped stopped}))))
 
 ;; composable set of states
 
diff --git a/test/core/mount/test/composable_fns.cljc b/test/core/mount/test/composable_fns.cljc
index a886413..b8b6ee2 100644
--- a/test/core/mount/test/composable_fns.cljc
+++ b/test/core/mount/test/composable_fns.cljc
@@ -167,4 +167,14 @@
       (let [scope #{}]
         (is (= {:started #{}} (-> (only scope)
                                   mount/start)))
-        (mount/stop)))))
+        (mount/stop)))
+
+    (testing "should not stop anything on empty seq of states"
+      (let [scope #{}]
+        (mount/start)
+        (is (instance? datomic.peer.LocalConnection (dval conn)))
+        (is (= {:stopped #{}} (-> (only scope)
+                                  mount/stop)))
+        (is (instance? datomic.peer.LocalConnection (dval conn)))
+        (mount/stop)
+        (is (instance? mount.core.NotStartedState (dval conn)))))))