Add ability to auto-approve followbacks

Resolves: https://akkoma.dev/AkkomaGang/akkoma/issues/148

CHANGELOG.md

@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## Added
 - Full compatibility with Erlang OTP26
 - handling of GET /api/v1/preferences
+- ability to auto-approve follow requests from users you are already following
 
 ## Changed
 - OTP builds are now built on erlang OTP26

docs/docs/development/API/differences_in_mastoapi_responses.md

@@ -117,6 +117,7 @@ Has these additional fields under the `akkoma` object:
 
 - `instance`: nullable object with metadata about the user’s instance
 - `status_ttl_days`: nullable int, default time after which statuses are deleted
+- `permit_followback`: boolean, whether follows from followed accounts are auto-approved
 
 ### Source
 

lib/pleroma/user.ex

@@ -160,6 +160,7 @@ defmodule Pleroma.User do
     field(:last_status_at, :naive_datetime)
     field(:language, :string)
     field(:status_ttl_days, :integer, default: nil)
+    field(:permit_followback, :boolean, default: false)
 
     field(:accepts_direct_messages_from, Ecto.Enum,
       values: [:everybody, :people_i_follow, :nobody],
@@ -544,6 +545,7 @@ defmodule Pleroma.User do
         :actor_type,
         :disclose_client,
         :status_ttl_days,
+        :permit_followback,
         :accepts_direct_messages_from
       ]
     )
@@ -972,16 +974,21 @@ defmodule Pleroma.User do
 
   def needs_update?(_), do: true
 
+  # "Locked" (self-locked) users demand explicit authorization of follow requests
+  @spec can_direct_follow_local(User.t(), User.t()) :: true | false
+  def can_direct_follow_local(%User{} = follower, %User{local: true} = followed) do
+    !followed.is_locked || (followed.permit_followback and is_friend_of(follower, followed))
+  end
+
   @spec maybe_direct_follow(User.t(), User.t()) ::
           {:ok, User.t(), User.t()} | {:error, String.t()}
 
-  # "Locked" (self-locked) users demand explicit authorization of follow requests
-  def maybe_direct_follow(%User{} = follower, %User{local: true, is_locked: true} = followed) do
-    follow(follower, followed, :follow_pending)
-  end
-
   def maybe_direct_follow(%User{} = follower, %User{local: true} = followed) do
-    follow(follower, followed)
+    if can_direct_follow_local(follower, followed) do
+      follow(follower, followed)
+    else
+      follow(follower, followed, :follow_pending)
+    end
   end
 
   def maybe_direct_follow(%User{} = follower, %User{} = followed) do
@@ -1331,6 +1338,13 @@ defmodule Pleroma.User do
     |> Repo.all()
   end
 
+  def is_friend_of(%User{} = potential_friend, %User{local: true} = user) do
+    user
+    |> get_friends_query()
+    |> where(id: ^potential_friend.id)
+    |> Repo.exists?()
+  end
+
   def increase_note_count(%User{} = user) do
     User
     |> where(id: ^user.id)

lib/pleroma/web/activity_pub/side_effects.ex

@@ -109,7 +109,7 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
          %User{} = followed <- User.get_cached_by_ap_id(followed_user),
          {_, {:ok, _, _}, _, _} <-
            {:following, User.follow(follower, followed, :follow_pending), follower, followed} do
-      if followed.local && !followed.is_locked do
+      if followed.local && User.can_direct_follow_local(follower, followed) do
         {:ok, accept_data, _} = Builder.accept(followed, object)
         {:ok, _activity, _} = Pipeline.common_pipeline(accept_data, local: true)
       end

lib/pleroma/web/api_spec/operations/account_operation.ex

@@ -723,6 +723,12 @@ defmodule Pleroma.Web.ApiSpec.AccountOperation do
           description:
             "Number of days after which statuses will be deleted. Set to -1 to disable."
         },
+        permit_followback: %Schema{
+          allOf: [BooleanLike],
+          nullable: true,
+          description:
+            "Whether follow requests from accounts the user is already following are auto-approved (when locked)."
+        },
         accepts_direct_messages_from: %Schema{
           type: :string,
           enum: [
@@ -754,6 +760,7 @@ defmodule Pleroma.Web.ApiSpec.AccountOperation do
         discoverable: false,
         actor_type: "Person",
         status_ttl_days: 30,
+        permit_followback: true,
         accepts_direct_messages_from: "everybody"
       }
     }

lib/pleroma/web/api_spec/schemas/account.ex

@@ -122,7 +122,8 @@ defmodule Pleroma.Web.ApiSpec.Schemas.Account do
               nodeinfo: %Schema{type: :object, nullable: true}
             }
           },
-          status_ttl_days: %Schema{type: :integer, nullable: true}
+          status_ttl_days: %Schema{type: :integer, nullable: true},
+          permit_followback: %Schema{type: :boolean}
         }
       },
       source: %Schema{
@@ -224,7 +225,8 @@ defmodule Pleroma.Web.ApiSpec.Schemas.Account do
               # XXX: nodeinfo schema
             }
         },
-        "status_ttl_days" => nil
+        "status_ttl_days" => nil,
+        "permit_followback" => true
       },
       "source" => %{
         "fields" => [],

lib/pleroma/web/mastodon_api/controllers/account_controller.ex

@@ -222,6 +222,7 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
       |> Maps.put_if_present(:language, Pleroma.Web.Gettext.normalize_locale(params[:language]))
       |> Maps.put_if_present(:status_ttl_days, params[:status_ttl_days], status_ttl_days_value)
       |> Maps.put_if_present(:accepts_direct_messages_from, params[:accepts_direct_messages_from])
+      |> Maps.put_if_present(:permit_followback, params[:permit_followback])
 
     # What happens here:
     #

lib/pleroma/web/mastodon_api/views/account_view.ex

@@ -292,7 +292,8 @@ defmodule Pleroma.Web.MastodonAPI.AccountView do
       last_status_at: user.last_status_at,
       akkoma: %{
         instance: render("instance.json", %{instance: instance}),
-        status_ttl_days: user.status_ttl_days
+        status_ttl_days: user.status_ttl_days,
+        permit_followback: user.permit_followback
       },
       # Pleroma extensions
       # Note: it's insecure to output :email but fully-qualified nickname may serve as safe stub

priv/repo/migrations/20240213120000_add_permit_followback.exs

@@ -0,0 +1,9 @@
+defmodule Pleroma.Repo.Migrations.AddPermitFollowback do
+  use Ecto.Migration
+
+  def change do
+    alter table(:users) do
+      add(:permit_followback, :boolean, null: false, default: false)
+    end
+  end
+end

test/pleroma/web/common_api_test.exs

@@ -1061,6 +1061,36 @@ defmodule Pleroma.Web.CommonAPITest do
 
       assert User.following?(follower, followed)
     end
+
+    test "directly follows back a locked, but followback-allowing local user" do
+      uopen = insert(:user, is_locked: false)
+      uselective = insert(:user, is_locked: true, permit_followback: true)
+
+      assert {:ok, uselective, uopen, %{data: %{"state" => "accept"}}} =
+               CommonAPI.follow(uselective, uopen)
+
+      assert User.get_follow_state(uselective, uopen) == :follow_accept
+
+      assert {:ok, uopen, uselective, %{data: %{"state" => "accept"}}} =
+               CommonAPI.follow(uopen, uselective)
+
+      assert User.get_follow_state(uopen, uselective) == :follow_accept
+    end
+
+    test "creates a pending request for locked, non-followback local user" do
+      uopen = insert(:user, is_locked: false)
+      ulocked = insert(:user, is_locked: true, permit_followback: false)
+
+      assert {:ok, ulocked, uopen, %{data: %{"state" => "accept"}}} =
+               CommonAPI.follow(ulocked, uopen)
+
+      assert User.get_follow_state(ulocked, uopen) == :follow_accept
+
+      assert {:ok, uopen, ulocked, %{data: %{"state" => "pending"}}} =
+               CommonAPI.follow(uopen, ulocked)
+
+      assert User.get_follow_state(uopen, ulocked) == :follow_pending
+    end
   end
 
   describe "unfollow/2" do

test/pleroma/web/mastodon_api/views/account_view_test.exs

@@ -65,7 +65,8 @@ defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
           },
           favicon: nil
         },
-        status_ttl_days: 5
+        status_ttl_days: 5,
+        permit_followback: false
       },
       avatar: "http://localhost:4001/images/avi.png",
       avatar_static: "http://localhost:4001/images/avi.png",
@@ -248,7 +249,8 @@ defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
           favicon: "http://localhost:4001/favicon.png",
           nodeinfo: %{version: "2.0"}
         },
-        status_ttl_days: nil
+        status_ttl_days: nil,
+        permit_followback: false
       },
       pleroma: %{
         ap_id: user.ap_id,