Join pre-release parts with "."

Signed-off-by: Eric Meadows-Jönsson <eric.meadows.jonsson@gmail.com>

Author: ericmj

lib/elixir/lib/version.ex

@@ -529,10 +529,11 @@ defimpl String.Chars, for: Version do
   end
 
   defp pre(pre) do
-    Enum.map(["-"] ++ pre, fn
-      int when is_integer(int) -> Integer.to_string(int)
-      string when is_binary(string) -> string
-    end)
+    "-" <>
+      Enum.map_join(pre, ".", fn
+        int when is_integer(int) -> Integer.to_string(int)
+        string when is_binary(string) -> string
+      end)
   end
 end
 

lib/elixir/test/elixir/version_test.exs

@@ -73,6 +73,7 @@ defmodule VersionTest do
     assert V.parse("1.0.0+lol") |> elem(1) |> to_string == "1.0.0+lol"
     assert V.parse("1.0.0-dev+lol") |> elem(1) |> to_string == "1.0.0-dev+lol"
     assert V.parse("1.0.0-0") |> elem(1) |> to_string == "1.0.0-0"
+    assert V.parse("1.0.0-rc.0") |> elem(1) |> to_string == "1.0.0-rc.0"
   end
 
   test "invalid match" do