Ellide if_set for domain types

Author: josevalim

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

@@ -3630,7 +3630,16 @@ defmodule Module.Types.Descr do
   def map_literal_to_quoted({domains = %{}, fields}, opts) do
     domain_fields =
       for {domain_key, value_type} <- domains do
-        {{domain_key, [], []}, map_value_to_quoted(value_type, opts)}
+        non_optional = remove_optional_static(value_type)
+
+        value_quoted =
+          if empty?(non_optional) do
+            {:not_set, [], []}
+          else
+            map_value_to_quoted(non_optional, opts)
+          end
+
+        {{domain_key, [], []}, value_quoted}
       end
 
     regular_fields_quoted = map_fields_to_quoted(:closed, Enum.sort(fields), opts)

lib/elixir/lib/module/types/of.ex

@@ -281,7 +281,7 @@ defmodule Module.Types.Of do
         {keys, union(old_type, new_type)}
       end)
 
-    {Enum.map(negated -- matched, fn key -> {key, none()} end) ++ single, multiple}
+    {Enum.map(negated -- matched, fn key -> {key, not_set()} end) ++ single, multiple}
   end
 
   defp pairs(pairs, expected, stack, context, of_fun) do

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

@@ -2286,10 +2286,10 @@ defmodule Module.Types.DescrTest do
 
     test "maps as dictionaries" do
       assert closed_map([{domain_key(:integer), integer()}])
-             |> to_quoted_string() == "%{integer() => if_set(integer())}"
+             |> to_quoted_string() == "%{integer() => integer()}"
 
-      assert closed_map([{domain_key(:integer), integer()}, {:float, float()}])
-             |> to_quoted_string() == "%{integer() => if_set(integer()), float: float()}"
+      assert closed_map([{domain_key(:integer), not_set()}, {:float, float()}])
+             |> to_quoted_string() == "%{integer() => not_set(), float: float()}"
     end
 
     test "structs" do

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

@@ -1202,7 +1202,7 @@ defmodule Module.Types.ExprTest do
 
              but got type:
 
-                 %{integer() => if_set(:old)}
+                 %{integer() => :old}
 
              where "key" was given the type:
 
@@ -1212,7 +1212,7 @@ defmodule Module.Types.ExprTest do
 
              where "x" was given the type:
 
-                 # type: %{integer() => if_set(:old)}
+                 # type: %{integer() => :old}
                  # from: types_test.ex:LINE-3
                  x = %{String.to_integer(key) => :old}
              """