Fix handling of Reject Follow when a matching follow relationship exists (#14479)

* Add tests

* Fix handling of Reject Follow when a matching follow relationship exists

Regression from #12199

app/lib/activitypub/activity/reject.rb

@@ -4,7 +4,7 @@ class ActivityPub::Activity::Reject < ActivityPub::Activity
   def perform
     return reject_follow_for_relay if relay_follow?
     return follow_request_from_object.reject! unless follow_request_from_object.nil?
-    return UnfollowService.new.call(follow_from_object.target_account, @account) unless follow_from_object.nil?
+    return UnfollowService.new.call(follow_from_object.account, @account) unless follow_from_object.nil?
 
     case @object['type']
     when 'Follow'

spec/lib/activitypub/activity/reject_spec.rb

@@ -3,6 +3,14 @@ require 'rails_helper'
 RSpec.describe ActivityPub::Activity::Reject do
   let(:sender)    { Fabricate(:account) }
   let(:recipient) { Fabricate(:account) }
+  let(:object_json) do
+    {
+      id: 'bar',
+      type: 'Follow',
+      actor: ActivityPub::TagManager.instance.uri_for(recipient),
+      object: ActivityPub::TagManager.instance.uri_for(sender),
+    }
+  end
 
   let(:json) do
     {
@@ -10,18 +18,14 @@ RSpec.describe ActivityPub::Activity::Reject do
       id: 'foo',
       type: 'Reject',
       actor: ActivityPub::TagManager.instance.uri_for(sender),
-      object: {
-        id: 'bar',
-        type: 'Follow',
-        actor: ActivityPub::TagManager.instance.uri_for(recipient),
-        object: ActivityPub::TagManager.instance.uri_for(sender),
-      },
+      object: object_json,
     }.with_indifferent_access
   end
 
   describe '#perform' do
     subject { described_class.new(json, sender) }
 
+    context 'rejecting a pending follow request by target' do
       before do
         Fabricate(:follow_request, account: recipient, target_account: sender)
         subject.perform
@@ -36,6 +40,86 @@ RSpec.describe ActivityPub::Activity::Reject do
       end
     end
 
+    context 'rejecting a pending follow request by uri' do
+      before do
+        Fabricate(:follow_request, account: recipient, target_account: sender, uri: 'bar')
+        subject.perform
+      end
+
+      it 'does not create a follow relationship' do
+        expect(recipient.following?(sender)).to be false
+      end
+
+      it 'removes the follow request' do
+        expect(recipient.requested?(sender)).to be false
+      end
+    end
+
+    context 'rejecting a pending follow request by uri only' do
+      let(:object_json) { 'bar' }
+
+      before do
+        Fabricate(:follow_request, account: recipient, target_account: sender, uri: 'bar')
+        subject.perform
+      end
+
+      it 'does not create a follow relationship' do
+        expect(recipient.following?(sender)).to be false
+      end
+
+      it 'removes the follow request' do
+        expect(recipient.requested?(sender)).to be false
+      end
+    end
+
+    context 'rejecting an existing follow relationship by target' do
+      before do
+        Fabricate(:follow, account: recipient, target_account: sender)
+        subject.perform
+      end
+
+      it 'removes the follow relationship' do
+        expect(recipient.following?(sender)).to be false
+      end
+
+      it 'does not create a follow request' do
+        expect(recipient.requested?(sender)).to be false
+      end
+    end
+
+    context 'rejecting an existing follow relationship by uri' do
+      before do
+        Fabricate(:follow, account: recipient, target_account: sender, uri: 'bar')
+        subject.perform
+      end
+
+      it 'removes the follow relationship' do
+        expect(recipient.following?(sender)).to be false
+      end
+
+      it 'does not create a follow request' do
+        expect(recipient.requested?(sender)).to be false
+      end
+    end
+
+    context 'rejecting an existing follow relationship by uri only' do
+      let(:object_json) { 'bar' }
+
+      before do
+        Fabricate(:follow, account: recipient, target_account: sender, uri: 'bar')
+        subject.perform
+      end
+
+      it 'removes the follow relationship' do
+        expect(recipient.following?(sender)).to be false
+      end
+
+      it 'does not create a follow request' do
+        expect(recipient.requested?(sender)).to be false
+      end
+    end
+  end
+
   context 'given a relay' do
     let!(:relay) { Fabricate(:relay, state: :pending, follow_activity_id: 'https://abc-123/456') }