Reject attributes in debug adapter completions

fix crash when attributes are returned from completion engine

Author: lukaszsamson

apps/debug_adapter/lib/debug_adapter/completions.ex

@@ -64,4 +64,7 @@ defmodule ElixirLS.DebugAdapter.Completions do
       label: name
     }
   end
+
+  # reject attributes as expansion will fail anyway
+  def map(%{type: :attribute}), do: nil
 end

apps/debug_adapter/lib/debug_adapter/server.ex

@@ -1478,6 +1478,7 @@ defmodule ElixirLS.DebugAdapter.Server do
       results =
         ElixirLS.Utils.CompletionEngine.complete(prefix, env, metadata, cursor_position)
         |> Enum.map(&ElixirLS.DebugAdapter.Completions.map/1)
+        |> Enum.reject(&is_nil/1)
 
       %{"targets" => results}
     end