added type parser test

integration/mssql/type_parser.exs

@@ -0,0 +1,28 @@
+defmodule Ecto.Integration.TypeParserTest do
+  use Ecto.Integration.Case, async: Application.get_env(:ecto, :async_integration_tests, true)
+
+  alias Ecto.Integration.TestRepo
+  import Ecto.Query
+
+  alias Ecto.Integration.Post
+  alias Ecto.Integration.Comment
+  alias Ecto.Integration.Permalink
+  alias Ecto.Integration.User
+  alias Ecto.Integration.PostUserCompositePk
+
+  test "joins with column alias" do
+    _p = TestRepo.insert!(%Post{title: "1"})
+    p2 = TestRepo.insert!(%Post{title: "2"})
+    c1 = TestRepo.insert!(%Permalink{url: "1", post_id: p2.id})
+
+    query =
+      from(p in Post,
+        join: c in assoc(p, :permalink),
+        on: c.id == ^c1.id,
+        select: %{post_id: p.id, link_id: c.id}
+      )
+
+    expected = %{link_id: c1.id, post_id: p2.id}
+    assert [expected] = TestRepo.all(query)
+  end
+end