Return an error when starting a server twice

whitfin · Sep 7, 2016 · 4094af7 · 4094af7
1 parent 7e32748
commit 4094af7
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Showing 2 changed files with 4 additions and 5 deletions.
diff --git a/lib/eternal/supervisor.ex b/lib/eternal/supervisor.ex
@@ -66,7 +66,7 @@ defmodule Eternal.Supervisor do
   # table twice. Otherwise, we execute the callback which will create the table.
   defp detect_clash(name, ets_opts, fun) do
     if exists?(name, ets_opts) do
-      { :ok, Process.whereis(name), name }
+      { :error, { :already_started, Process.whereis(name) } }
     else
       fun.()
     end

diff --git a/test/eternal_test.exs b/test/eternal_test.exs
@@ -72,10 +72,9 @@ defmodule EternalTest do
   end
 
   test "starting a table twice finds the previous owner" do
-    { :ok, pid1 } = Eternal.start_link(:existing_table, [], [ quiet: true ])
-    { :ok, pid2 } = Eternal.start_link(:existing_table, [], [ quiet: true ])
-
-    assert(pid1 == pid2)
+    { :ok, pid } = Eternal.start_link(:existing_table, [], [ quiet: true ])
+    result2 = Eternal.start_link(:existing_table, [], [ quiet: true ])
+    assert(result2 == { :error, { :already_started, pid } })
   end
 
   test "deprecation warnings when using new/3" do