Fix line number incrementing. Add test.

lib/lex_luthor.ex

@@ -80,7 +80,7 @@ defmodule LexLuthor do
         lexer
       _ ->
         # Increment lexer position
-        line = (String.slice(string, 0, len) |> String.split(~r{(\r|\n|\r\n)}) |> Enum.count) + lexer.line
+        line = (String.slice(string, 0, len) |> String.split(~r{(\r|\n|\r\n)}) |> Enum.count) - 1 + lexer.line
         lexer = %State{ pos: lexer.pos + len, line: line, states: lexer.states, tokens: lexer.tokens }
 
         # Are we at the end of the string?

test/acceptance_test.exs

@@ -34,4 +34,12 @@ defmodule AcceptanceTest do
       end
   end
 
+  test "String #{inspect "foo\nbar"} has correct line numbers" do
+    {ok, tokens} = ExampleLexer.lex "'foo'\n'bar'"
+    assert ok == :ok
+
+    token = List.last tokens
+    assert token.line == 2
+  end
+
 end