First attempt on Elixir location tests

test/elixir_sense/location_test.exs

@@ -0,0 +1,32 @@
+defmodule ElixirSense.LocationTest do
+  use ExUnit.Case, async: false
+
+  import ElixirSense.Location
+
+  setup do
+    elixir_src = Path.join(File.cwd!(), "/test/misc/mock_elixir_src")
+    Application.put_env(:elixir_sense, :elixir_src, elixir_src)
+
+    on_exit(fn ->
+      Application.delete_env(:elixir_sense, :elixir_src)
+    end)
+  end
+
+  describe "find_mod_fun_source/3" do
+    test "returns location of a core Elixir function" do
+      assert %ElixirSense.Location{type: :function, line: 2017, column: 3, file: file} =
+               find_mod_fun_source(String, :length, 1)
+
+      assert String.ends_with?(file, "/mock_elixir_src/lib/elixir/lib/string.ex")
+    end
+  end
+
+  describe "find_type_source/3" do
+    test "returns location of a core Elixir type" do
+      assert %ElixirSense.Location{type: :typespec, line: 269, column: 3, file: file} =
+               find_type_source(String, :t, 0)
+
+      assert String.ends_with?(file, "/mock_elixir_src/lib/elixir/lib/string.ex")
+    end
+  end
+end