Fix gettext line break reject

lib/langue/formatter/gettext/parser.ex

@@ -7,8 +7,8 @@ defmodule Langue.Formatter.Gettext.Parser do
   def parse(%{render: render, document: document}) do
     {:ok, po} = Gettext.PO.parse_string(render)
     entries = parse_translations(po)
-    top_of_the_file_comment = join_string(po.top_of_the_file_comments)
-    header = join_string(po.headers)
+    top_of_the_file_comment = join_string(po.top_of_the_file_comments, "\n")
+    header = join_string(po.headers, "\n")
 
     %Langue.Formatter.ParserResult{
       entries: entries,
@@ -73,8 +73,9 @@ defmodule Langue.Formatter.Gettext.Parser do
     ]
   end
 
-  defp join_string([]), do: nil
-  defp join_string(list), do: Enum.join(list, "\n")
+  defp join_string(list, joiner \\ "")
+  defp join_string([], _joiner), do: nil
+  defp join_string(list, joiner), do: Enum.join(list, joiner)
 
   defp key_suffix(id), do: ".__KEY__#{id}"
 

lib/langue/formatter/gettext/serializer.ex

@@ -91,7 +91,6 @@ defmodule Langue.Formatter.Gettext.Serializer do
       ["\n" | rest] -> ["" | rest]
       values -> values
     end
-    |> Enum.reject(&(&1 === "\n"))
   end
 
   defp remove_key_suffix(string), do: String.replace(string, ".__KEY___", "")

test/langue/gettext/expectation_test.exs

@@ -172,15 +172,15 @@ defmodule LangueTest.Formatter.Gettext.Expectation do
     def render do
       """
       msgid "test"
-      msgstr ""
-      "a\\n"
-      "a\\n"
+      msgstr "This is a test\\n"
+      "\\n"
+      "multi line break"
       """
     end
 
     def entries do
       [
-        %Entry{index: 1, key: "test", value: "\na\n\na\n", value_type: "string"}
+        %Entry{index: 1, key: "test", value: "This is a test\n\nmulti line break", value_type: "string"}
       ]
     end
   end