Change move handler to carry blocks over (#14144)

* Change move handler to carry blocks and mutes over

When user A blocks user B and B moves to a new account C, make A block C
accordingly.

Note that it only works if A's instance is aware of the Move, that is,
if B is on A's instance or has followers there.

* Also notify instances with known people blocking you when moving

* Add automatic account notes when blocking/muting an account that had no note

spec/workers/move_worker_spec.rb

@@ -4,20 +4,29 @@ require 'rails_helper'
 
 describe MoveWorker do
   let(:local_follower)   { Fabricate(:user, email: 'bob@example.com', account: Fabricate(:account, username: 'bob')).account }
+  let(:blocking_account) { Fabricate(:user, email: 'bar@example.com', account: Fabricate(:account, username: 'bar')).account }
+  let(:muting_account)   { Fabricate(:user, email: 'foo@example.com', account: Fabricate(:account, username: 'foo')).account }
   let(:source_account)   { Fabricate(:account, protocol: :activitypub, domain: 'example.com') }
   let(:target_account)   { Fabricate(:account, protocol: :activitypub, domain: 'example.com') }
   let(:local_user)       { Fabricate(:user) }
   let!(:account_note)    { Fabricate(:account_note, account: local_user.account, target_account: source_account) }
 
+  let(:block_service) { double }
+
   subject { described_class.new }
 
   before do
     local_follower.follow!(source_account)
+    blocking_account.block!(source_account)
+    muting_account.mute!(source_account)
+
+    allow(UnfollowFollowWorker).to receive(:push_bulk)
+    allow(BlockService).to receive(:new).and_return(block_service)
+    allow(block_service).to receive(:call)
   end
 
   shared_examples 'user note handling' do
     it 'copies user note' do
-      allow(UnfollowFollowWorker).to receive(:push_bulk)
       subject.perform(source_account.id, target_account.id)
       expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(source_account.acct)
       expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(account_note.comment)
@@ -26,7 +35,6 @@ describe MoveWorker do
     it 'merges user notes when needed' do
       new_account_note = AccountNote.create!(account: account_note.account, target_account: target_account, comment: 'new note prior to move')
 
-      allow(UnfollowFollowWorker).to receive(:push_bulk)
       subject.perform(source_account.id, target_account.id)
       expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(source_account.acct)
       expect(AccountNote.find_by(account: account_note.account, target_account: target_account).comment).to include(account_note.comment)
@@ -34,15 +42,29 @@ describe MoveWorker do
     end
   end
 
+  shared_examples 'block and mute handling' do
+    it 'makes blocks carry over and add a note' do
+      subject.perform(source_account.id, target_account.id)
+      expect(block_service).to have_received(:call).with(blocking_account, target_account)
+      expect(AccountNote.find_by(account: blocking_account, target_account: target_account).comment).to include(source_account.acct)
+    end
+
+    it 'makes mutes carry over and add a note' do
+      subject.perform(source_account.id, target_account.id)
+      expect(muting_account.muting?(target_account)).to be true
+      expect(AccountNote.find_by(account: muting_account, target_account: target_account).comment).to include(source_account.acct)
+    end
+  end
+
   context 'both accounts are distant' do
     describe 'perform' do
       it 'calls UnfollowFollowWorker' do
-        allow(UnfollowFollowWorker).to receive(:push_bulk)
         subject.perform(source_account.id, target_account.id)
         expect(UnfollowFollowWorker).to have_received(:push_bulk).with([local_follower.id])
       end
 
       include_examples 'user note handling'
+      include_examples 'block and mute handling'
     end
   end
 
@@ -51,12 +73,12 @@ describe MoveWorker do
 
     describe 'perform' do
       it 'calls UnfollowFollowWorker' do
-        allow(UnfollowFollowWorker).to receive(:push_bulk)
         subject.perform(source_account.id, target_account.id)
         expect(UnfollowFollowWorker).to have_received(:push_bulk).with([local_follower.id])
       end
 
       include_examples 'user note handling'
+      include_examples 'block and mute handling'
     end
   end
 
@@ -71,6 +93,7 @@ describe MoveWorker do
       end
 
       include_examples 'user note handling'
+      include_examples 'block and mute handling'
 
       it 'does not fail when a local user is already following both accounts' do
         double_follower = Fabricate(:user, email: 'eve@example.com', account: Fabricate(:account, username: 'eve')).account