Excluded source files in build directory

Fixes #456

apps/remote_control/lib/lexical/remote_control/search/indexer.ex

@@ -40,7 +40,7 @@ defmodule Lexical.RemoteControl.Search.Indexer do
 
     project_files =
       project
-      |> indexable_files
+      |> indexable_files()
       |> MapSet.new()
 
     previously_indexed_paths = MapSet.new(path_to_ids, fn {path, _} -> path end)
@@ -176,10 +176,12 @@ defmodule Lexical.RemoteControl.Search.Indexer do
 
   def indexable_files(%Project{} = project) do
     root_dir = Project.root_path(project)
+    build_dir = build_dir()
 
     [root_dir, "**", @indexable_extensions]
     |> Path.join()
     |> Path.wildcard()
+    |> Enum.reject(&contained_in?(&1, build_dir))
   end
 
   # stat(path) is here for testing so it can be mocked
@@ -199,4 +201,11 @@ defmodule Lexical.RemoteControl.Search.Indexer do
       _ -> Mix.Project.deps_path()
     end
   end
+
+  defp build_dir do
+    case RemoteControl.Mix.in_project(&Mix.Project.build_path/0) do
+      {:ok, path} -> path
+      _ -> Mix.Project.build_path()
+    end
+  end
 end