Support /authorize-interaction route used by Mastodon

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

changelog.d/authorize-interaction.add

@@ -0,0 +1 @@
+Support /authorize-interaction route used by Mastodon

lib/pleroma/web/router.ex

@@ -465,6 +465,8 @@ defmodule Pleroma.Web.Router do
     get("/main/ostatus", UtilController, :show_subscribe_form)
     get("/ostatus_subscribe", RemoteFollowController, :follow)
     post("/ostatus_subscribe", RemoteFollowController, :do_follow)
+
+    get("/authorize_interaction", RemoteFollowController, :authorize_interaction)
   end
 
   scope "/api/pleroma", Pleroma.Web.TwitterAPI do

lib/pleroma/web/twitter_api/controllers/remote_follow_controller.ex

@@ -121,6 +121,13 @@ def do_follow(%{assigns: %{user: nil}} = conn, _) do
     render(conn, "followed.html", %{error: "Insufficient permissions: follow | write:follows."})
   end
 
+  # GET /authorize_interaction
+  #
+  def authorize_interaction(conn, %{"uri" => uri}) do
+    conn
+    |> redirect(to: Routes.remote_follow_path(conn, :follow, %{acct: uri}))
+  end
+
   defp handle_follow_error(conn, {:mfa_token, followee, _} = _) do
     render(conn, "follow_login.html", %{error: "Wrong username or password", followee: followee})
   end

test/pleroma/web/plugs/frontend_static_plug_test.exs

@@ -82,6 +82,7 @@ test "api routes are detected correctly" do
       "api",
       "main",
       "ostatus_subscribe",
+      "authorize_interaction",
       "oauth",
       "objects",
       "activities",

test/pleroma/web/twitter_api/remote_follow_controller_test.exs

@@ -455,4 +455,38 @@ test "local avatar is not proxied" do
       assert avatar_url == "#{Pleroma.Web.Endpoint.url()}/localuser/avatar.png"
     end
   end
+
+  describe "GET /authorize_interaction - authorize_interaction/2" do
+    test "redirects to /ostatus_subscribe", %{conn: conn} do
+      Tesla.Mock.mock(fn
+        %{method: :get, url: "https://mastodon.social/users/emelie"} ->
+          %Tesla.Env{
+            status: 200,
+            headers: [{"content-type", "application/activity+json"}],
+            body: File.read!("test/fixtures/tesla_mock/emelie.json")
+          }
+
+        %{method: :get, url: "https://mastodon.social/users/emelie/collections/featured"} ->
+          %Tesla.Env{
+            status: 200,
+            headers: [{"content-type", "application/activity+json"}],
+            body:
+              File.read!("test/fixtures/users_mock/masto_featured.json")
+              |> String.replace("{{domain}}", "mastodon.social")
+              |> String.replace("{{nickname}}", "emelie")
+          }
+      end)
+
+      conn =
+        conn
+        |> get(
+          remote_follow_path(conn, :authorize_interaction, %{
+            uri: "https://mastodon.social/users/emelie"
+          })
+        )
+
+      assert redirected_to(conn) ==
+               remote_follow_path(conn, :follow, %{acct: "https://mastodon.social/users/emelie"})
+    end
+  end
 end