Fix follow suggestions potentially including silenced or blocked accounts (#29306)

spec/models/account_suggestions/friends_of_friends_source_spec.rb

@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe AccountSuggestions::FriendsOfFriendsSource do
+  describe '#get' do
+    subject { described_class.new }
+
+    let!(:bob) { Fabricate(:account, discoverable: true, hide_collections: false) }
+    let!(:alice) { Fabricate(:account, discoverable: true, hide_collections: true) }
+    let!(:eve) { Fabricate(:account, discoverable: true, hide_collections: false) }
+    let!(:mallory) { Fabricate(:account, discoverable: false, hide_collections: false) }
+    let!(:eugen) { Fabricate(:account, discoverable: true, hide_collections: false) }
+    let!(:john) { Fabricate(:account, discoverable: true, hide_collections: false) }
+    let!(:jerk) { Fabricate(:account, discoverable: true, hide_collections: false) }
+    let!(:neil) { Fabricate(:account, discoverable: true, hide_collections: false) }
+    let!(:larry) { Fabricate(:account, discoverable: true, hide_collections: false) }
+
+    context 'with follows and blocks' do
+      before do
+        bob.block!(jerk)
+        FollowRecommendationMute.create!(account: bob, target_account: neil)
+
+        # bob follows eugen, alice and larry
+        [eugen, alice, larry].each { |account| bob.follow!(account) }
+
+        # alice follows eve and mallory
+        [john, mallory].each { |account| alice.follow!(account) }
+
+        # eugen follows eve, john, jerk, larry and neil
+        [eve, mallory, jerk, larry, neil].each { |account| eugen.follow!(account) }
+      end
+
+      it 'returns eligible accounts', :aggregate_failures do
+        results = subject.get(bob)
+
+        # eve is returned through eugen
+        expect(results).to include([eve.id, :friends_of_friends])
+
+        # john is not reachable because alice hides who she follows
+        expect(results).to_not include([john.id, :friends_of_friends])
+
+        # mallory is not discoverable
+        expect(results).to_not include([mallory.id, :friends_of_friends])
+
+        # larry is not included because he's followed already
+        expect(results).to_not include([larry.id, :friends_of_friends])
+
+        # jerk is blocked
+        expect(results).to_not include([jerk.id, :friends_of_friends])
+
+        # the suggestion for neil has already been rejected
+        expect(results).to_not include([neil.id, :friends_of_friends])
+      end
+    end
+
+    context 'with deterministic order' do
+      before do
+        # bob follows eve and mallory
+        [eve, mallory].each { |account| bob.follow!(account) }
+
+        # eve follows eugen, john, and jerk
+        [jerk, eugen, john].each { |account| eve.follow!(account) }
+
+        # mallory follows eugen, john, and neil
+        [neil, eugen, john].each { |account| mallory.follow!(account) }
+
+        john.follow!(eugen)
+        john.follow!(neil)
+      end
+
+      it 'returns eligible accounts in the expected order' do
+        expect(subject.get(bob)).to eq [
+          [eugen.id, :friends_of_friends], # followed by 2 friends, 3 followers total
+          [john.id, :friends_of_friends], # followed by 2 friends, 2 followers total
+          [neil.id, :friends_of_friends], # followed by 1 friend, 2 followers total
+          [jerk.id, :friends_of_friends], # followed by 1 friend, 1 follower total
+        ]
+      end
+    end
+  end
+end

spec/models/account_suggestions/source_spec.rb

@@ -11,14 +11,16 @@ RSpec.describe AccountSuggestions::Source do
     end
 
     context 'with follows and follow requests' do
-      let!(:account_domain_blocked_account) { Fabricate(:account, domain: 'blocked.host') }
-      let!(:account) { Fabricate(:account) }
-      let!(:blocked_account) { Fabricate(:account) }
-      let!(:eligible_account) { Fabricate(:account) }
-      let!(:follow_recommendation_muted_account) { Fabricate(:account) }
-      let!(:follow_requested_account) { Fabricate(:account) }
-      let!(:following_account) { Fabricate(:account) }
-      let!(:moved_account) { Fabricate(:account, moved_to_account: Fabricate(:account)) }
+      let!(:account_domain_blocked_account) { Fabricate(:account, domain: 'blocked.host', discoverable: true) }
+      let!(:account) { Fabricate(:account, discoverable: true) }
+      let!(:blocked_account) { Fabricate(:account, discoverable: true) }
+      let!(:eligible_account) { Fabricate(:account, discoverable: true) }
+      let!(:follow_recommendation_muted_account) { Fabricate(:account, discoverable: true) }
+      let!(:follow_requested_account) { Fabricate(:account, discoverable: true) }
+      let!(:following_account) { Fabricate(:account, discoverable: true) }
+      let!(:moved_account) { Fabricate(:account, moved_to_account: Fabricate(:account), discoverable: true) }
+      let!(:silenced_account) { Fabricate(:account, silenced: true, discoverable: true) }
+      let!(:undiscoverable_account) { Fabricate(:account, discoverable: false) }
 
       before do
         Fabricate :account_domain_block, account: account, domain: account_domain_blocked_account.domain
@@ -40,6 +42,8 @@ RSpec.describe AccountSuggestions::Source do
           .and not_include(follow_requested_account)
           .and not_include(following_account)
           .and not_include(moved_account)
+          .and not_include(silenced_account)
+          .and not_include(undiscoverable_account)
       end
     end
   end