Add router macro for HEAD requests (#962)

lib/plug/router.ex

@@ -381,6 +381,14 @@ defmodule Plug.Router do
     compile(:get, path, options, contents)
   end
 
+  @doc """
+  Dispatches to the path only if the request is a HEAD request.
+  See `match/3` for more examples.
+  """
+  defmacro head(path, options, contents \\ []) do
+    compile(:head, path, options, contents)
+  end
+
   @doc """
   Dispatches to the path only if the request is a POST request.
   See `match/3` for more examples.

test/plug/router_test.exs

@@ -144,6 +144,10 @@ defmodule Plug.RouterTest do
       resp(conn, 200, inspect(conn.assigns))
     end
 
+    head "/head" do
+      resp(conn, 200, "")
+    end
+
     post "/post" do
       resp(conn, 200, "")
     end
@@ -451,6 +455,11 @@ defmodule Plug.RouterTest do
     assert conn.resp_body =~ ~s(an_option: :a_value)
   end
 
+  test "declare and call HEAD requests" do
+    conn = call(Sample, conn(:head, "/head"))
+    assert conn.status == 200
+  end
+
   test "declare and call POST requests" do
     conn = call(Sample, conn(:post, "/post"))
     assert conn.status == 200