From 9fe3f4f6d85bde55ff8b4c2be6846bfb46786278 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20=C5=81=C4=99picki?=
 <michallepicki@users.noreply.github.com>
Date: Fri, 18 Mar 2022 22:32:14 +0100
Subject: [PATCH 1/2] Give better names to types regression tests

---
 lib/elixir/test/elixir/module/types/types_test.exs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/elixir/test/elixir/module/types/types_test.exs b/lib/elixir/test/elixir/module/types/types_test.exs
index 383a5880dd8..22c260c1371 100644
--- a/lib/elixir/test/elixir/module/types/types_test.exs
+++ b/lib/elixir/test/elixir/module/types/types_test.exs
@@ -706,7 +706,7 @@ defmodule Module.Types.TypesTest do
              ) == :none
     end
 
-    test "other recursive" do
+    test "map patterns with pinned keys and field access" do
       assert warning(
                [x, y],
                (
@@ -719,7 +719,7 @@ defmodule Module.Types.TypesTest do
              ) == :none
     end
 
-    test "other recursive2" do
+    test "map patterns with pinned keys" do
       assert warning(
                [x, y],
                (

From 782643672147a11bd615d6033af8708f985f9178 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20=C5=81=C4=99picki?=
 <michallepicki@users.noreply.github.com>
Date: Sat, 19 Mar 2022 23:20:01 +0100
Subject: [PATCH 2/2] Change map updates type checking direction

closes #11709
---
 lib/elixir/lib/module/types/expr.ex                |  2 +-
 lib/elixir/test/elixir/module/types/map_test.exs   | 10 +++++-----
 lib/elixir/test/elixir/module/types/types_test.exs | 12 ++++++++++++
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/lib/elixir/lib/module/types/expr.ex b/lib/elixir/lib/module/types/expr.ex
index 02363cb0042..1fb7ea3651a 100644
--- a/lib/elixir/lib/module/types/expr.ex
+++ b/lib/elixir/lib/module/types/expr.ex
@@ -151,7 +151,7 @@ defmodule Module.Types.Expr do
          dynamic_value_pairs =
            Enum.map(arg_pairs, fn {:required, key, _value} -> {:required, key, :dynamic} end),
          args_type = {:map, dynamic_value_pairs ++ [{:optional, :dynamic, :dynamic}]},
-         {:ok, type, context} <- unify(args_type, map_type, stack, context) do
+         {:ok, type, context} <- unify(map_type, args_type, stack, context) do
       # Retrieve map type and overwrite with the new value types from the map update
       {:map, pairs} = resolve_var(type, context)
 
diff --git a/lib/elixir/test/elixir/module/types/map_test.exs b/lib/elixir/test/elixir/module/types/map_test.exs
index 5324c845399..da6818f2e54 100644
--- a/lib/elixir/test/elixir/module/types/map_test.exs
+++ b/lib/elixir/test/elixir/module/types/map_test.exs
@@ -201,8 +201,8 @@ defmodule Module.Types.MapTest do
 
     assert {:error,
             {:unable_unify,
-             {{:map, [{:required, {:atom, :bar}, :dynamic}, {:optional, :dynamic, :dynamic}]},
-              {:map, [{:required, {:atom, :foo}, {:atom, :a}}]},
+             {{:map, [{:required, {:atom, :foo}, {:atom, :a}}]},
+              {:map, [{:required, {:atom, :bar}, :dynamic}, {:optional, :dynamic, :dynamic}]},
               _}}} =
              quoted_expr(
                (
@@ -231,8 +231,8 @@ defmodule Module.Types.MapTest do
             {:unable_unify,
              {{:map,
                [
-                 {:required, {:atom, :field}, {:atom, :b}},
                  {:required, {:atom, :foo}, {:var, 1}},
+                 {:required, {:atom, :field}, {:atom, :b}},
                  {:optional, :dynamic, :dynamic}
                ]},
               {:map,
@@ -276,12 +276,12 @@ defmodule Module.Types.MapTest do
     assert {:error,
             {:unable_unify,
              {{:map,
-               [{:required, {:atom, :not_field}, :dynamic}, {:optional, :dynamic, :dynamic}]},
-              {:map,
                [
                  {:required, {:atom, :field}, {:atom, nil}},
                  {:required, {:atom, :__struct__}, {:atom, Module.Types.MapTest.Struct2}}
                ]},
+              {:map,
+               [{:required, {:atom, :not_field}, :dynamic}, {:optional, :dynamic, :dynamic}]},
               _}}} =
              quoted_expr(
                (
diff --git a/lib/elixir/test/elixir/module/types/types_test.exs b/lib/elixir/test/elixir/module/types/types_test.exs
index 22c260c1371..fcec53f2267 100644
--- a/lib/elixir/test/elixir/module/types/types_test.exs
+++ b/lib/elixir/test/elixir/module/types/types_test.exs
@@ -732,5 +732,17 @@ defmodule Module.Types.TypesTest do
                )
              ) == :none
     end
+
+    test "map updates with var key" do
+      assert warning(
+               [state0, key0],
+               (
+                 state1 = %{state0 | key0 => true}
+                 key1 = key0
+                 state2 = %{state1 | key1 => true}
+                 state2
+               )
+             ) == :none
+    end
   end
 end