Print dynamic(none()) as none()

Author: josevalim

lib/elixir/lib/module/types.ex

@@ -27,6 +27,7 @@ defmodule Module.Types do
       # TODO: Reuse context from patterns and guards
       # TODO: Simplify pair types
       # TODO: Handle local calls
+      # TODO: Improve errors on bad apply if one of the arguments are empty
       {{fun, arity}, {:infer, pair_types}}
     end
   end

lib/elixir/lib/module/types/descr.ex

@@ -1145,9 +1145,17 @@ defmodule Module.Types.Descr do
 
   defp dynamic_to_quoted(descr) do
     cond do
-      term_type?(descr) -> [{:dynamic, [], []}]
-      single = indivisible_bitmap(descr) -> [single]
-      true -> [{:dynamic, [], [to_quoted(descr)]}]
+      term_type?(descr) ->
+        [{:dynamic, [], []}]
+
+      single = indivisible_bitmap(descr) ->
+        [single]
+
+      true ->
+        case to_quoted(descr) do
+          {:none, _meta, []} = none -> [none]
+          descr -> [{:dynamic, [], [descr]}]
+        end
     end
   end
 

lib/elixir/test/elixir/module/types/descr_test.exs

@@ -1163,6 +1163,7 @@ defmodule Module.Types.DescrTest do
 
     test "none" do
       assert none() |> to_quoted_string() == "none()"
+      assert dynamic(none()) |> to_quoted_string() == "none()"
     end
 
     test "negation" do