Implement no-op support for Plug.Conn.Adapter.upgrade/3

lib/bandit/http1/adapter.ex

@@ -308,6 +308,9 @@ defmodule Bandit.HTTP1.Adapter do
   @impl Plug.Conn.Adapter
   def inform(_req, _status, _headers), do: {:error, :not_supported}
 
+  @impl Plug.Conn.Adapter
+  def upgrade(_req, _upgrade, _opts), do: {:error, :not_supported}
+
   @impl Plug.Conn.Adapter
   def push(_req, _path, _headers), do: {:error, :not_supported}
 

lib/bandit/http2/adapter.ex

@@ -128,6 +128,9 @@ defmodule Bandit.HTTP2.Adapter do
     GenServer.call(adapter.connection, {:send_headers, adapter.stream_id, headers, false})
   end
 
+  @impl Plug.Conn.Adapter
+  def upgrade(_req, _upgrade, _opts), do: {:error, :not_supported}
+
   @impl Plug.Conn.Adapter
   def push(_adapter, _path, _headers), do: {:error, :not_supported}
 

test/bandit/http1/request_test.exs

@@ -297,6 +297,23 @@ defmodule HTTP1RequestTest do
     end
   end
 
+  describe "upgrade handling" do
+    test "does not update the conn or send any data on unsupported upgrades", context do
+      {:ok, response} =
+        Finch.build(:get, context[:base] <> "/upgrade_unsupported", [{"connection", "close"}])
+        |> Finch.request(context[:finch_name])
+
+      assert response.status == 200
+      assert response.body == "Not supported"
+    end
+
+    def upgrade_unsupported(conn) do
+      conn
+      |> upgrade_adapter(:unsupported, [])
+      |> send_resp(200, "Not supported")
+    end
+  end
+
   test "does not do anything special with EXIT messages from abnormally terminating spwaned processes",
        context do
     errors =

test/bandit/http2/plug_test.exs

@@ -208,6 +208,23 @@ defmodule HTTP2PlugTest do
     |> elem(1)
   end
 
+  describe "upgrade handling" do
+    test "does not update the conn or send any data on unsupported upgrades", context do
+      {:ok, response} =
+        Finch.build(:get, context[:base] <> "/upgrade_unsupported")
+        |> Finch.request(context[:finch_name])
+
+      assert response.status == 200
+      assert response.body == "Not supported"
+    end
+
+    def upgrade_unsupported(conn) do
+      conn
+      |> upgrade_adapter(:unsupported, [])
+      |> send_resp(200, "Not supported")
+    end
+  end
+
   test "raises a Plug.Conn.NotSentError if nothing was set in the conn", context do
     errors =
       capture_log(fn ->