Merge 1e54bf6ff2 into 3c7f3b190c

.env.production.sample

@@ -86,3 +86,24 @@ S3_ALIAS_HOST=files.example.com
 # -----------------------
 IP_RETENTION_PERIOD=31556952
 SESSION_RETENTION_PERIOD=31556952
+
+# Fetch All Replies Behavior
+# --------------------------
+# When a user expands a post (DetailedStatus view), fetch all of its replies
+# (default: true if unset, set explicitly to ``false`` to disable)
+FETCH_REPLIES_ENABLED=true
+
+# Period to wait between fetching replies (in minutes)
+FETCH_REPLIES_DEBOUNCE=15
+
+# Period to wait after a post is first created before fetching its replies (in minutes)
+FETCH_REPLIES_CREATED_RECENTLY=5
+
+# Max number of replies to fetch - total, recursively through a whole reply tree
+FETCH_REPLIES_MAX_GLOBAL=1000
+
+# Max number of replies to fetch - for a single post
+FETCH_REPLIES_MAX_SINGLE=500
+
+# Max number of replies Collection pages to fetch - total
+FETCH_REPLIES_MAX_PAGES=500

app/controllers/api/v1/statuses_controller.rb

@@ -58,6 +58,15 @@ class Api::V1::StatusesController < Api::BaseController
     statuses = [@status] + @context.ancestors + @context.descendants
 
     render json: @context, serializer: REST::ContextSerializer, relationships: StatusRelationshipsPresenter.new(statuses, current_user&.account_id)
+
+    if !current_account.nil? && @status.should_fetch_replies?
+      ActivityPub::FetchAllRepliesWorker.perform_async(
+        @status.id,
+        {
+          allow_synchronous_requests: true,
+        }
+      )
+    end
   end
 
   def create

app/models/concerns/status/fetch_replies_concern.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module Status::FetchRepliesConcern
+  extend ActiveSupport::Concern
+
+  # enable/disable fetching all replies
+  FETCH_REPLIES_ENABLED = ENV.key?('FETCH_REPLIES_ENABLED') ? ENV['FETCH_REPLIES_ENABLED'] == 'true' : true
+
+  # debounce fetching all replies to minimize DoS
+  FETCH_REPLIES_DEBOUNCE = (ENV['FETCH_REPLIES_DEBOUNCE'] || 15).to_i.minutes
+  CREATED_RECENTLY_DEBOUNCE = (ENV['FETCH_REPLIES_CREATED_RECENTLY'] || 5).to_i.minutes
+
+  included do
+    scope :created_recently, -> { where(created_at: CREATED_RECENTLY_DEBOUNCE.ago..) }
+    scope :not_created_recently, -> { where(created_at: ..CREATED_RECENTLY_DEBOUNCE.ago) }
+    scope :fetched_recently, -> { where(fetched_replies_at: FETCH_REPLIES_DEBOUNCE.ago..) }
+    scope :not_fetched_recently, -> { where(fetched_replies_at: ..FETCH_REPLIES_DEBOUNCE.ago).or(where(fetched_replies_at: nil)) }
+
+    scope :should_not_fetch_replies, -> { local.merge(created_recently).merge(fetched_recently) }
+    scope :should_fetch_replies, -> { local.invert_where.merge(not_created_recently).merge(not_fetched_recently) }
+  end
+
+  def should_fetch_replies?
+    # we aren't brand new, and we haven't fetched replies since the debounce window
+    FETCH_REPLIES_ENABLED && !local? && created_at <= CREATED_RECENTLY_DEBOUNCE.ago && (
+      fetched_replies_at.nil? || fetched_replies_at <= FETCH_REPLIES_DEBOUNCE.ago
+    )
+  end
+end

app/models/status.rb

@@ -27,6 +27,7 @@
 #  edited_at                    :datetime
 #  trendable                    :boolean
 #  ordered_media_attachment_ids :bigint(8)        is an Array
+#  fetched_replies_at           :datetime
 #
 
 class Status < ApplicationRecord
@@ -34,6 +35,7 @@ class Status < ApplicationRecord
   include Discard::Model
   include Paginable
   include RateLimitable
+  include Status::FetchRepliesConcern
   include Status::SafeReblogInsert
   include Status::SearchConcern
   include Status::SnapshotConcern

app/services/activitypub/fetch_all_replies_service.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+class ActivityPub::FetchAllRepliesService < ActivityPub::FetchRepliesService
+  include JsonLdHelper
+
+  # Limit of replies to fetch per status
+  MAX_REPLIES = (ENV['FETCH_REPLIES_MAX_SINGLE'] || 500).to_i
+
+  def call(collection_or_uri, max_pages = nil, request_id: nil)
+    @allow_synchronous_requests = true
+    @filter_by_host = false
+    @collection_or_uri = collection_or_uri
+
+    @items, n_pages = collection_items(collection_or_uri, max_pages)
+    @items = filtered_replies
+    return if @items.nil?
+
+    FetchReplyWorker.push_bulk(@items) { |reply_uri| [reply_uri, { 'request_id' => request_id }] }
+
+    [@items, n_pages]
+  end
+
+  private
+
+  def filtered_replies
+    return if @items.nil?
+
+    # Find all statuses that we *shouldn't* update the replies for, and use that as a filter.
+    # We don't assume that we have the statuses before they're created,
+    # hence the negative filter -
+    # "keep all these uris except the ones we already have"
+    # instead of
+    # "keep all these uris that match some conditions on existing Status objects"
+    #
+    # Typically we assume the number of replies we *shouldn't* fetch is smaller than the
+    # replies we *should* fetch, so we also minimize the number of uris we should load here.
+    uris = @items.map { |item| value_or_id(item) }
+    dont_update = Status.where(uri: uris).should_not_fetch_replies.pluck(:uri)
+
+    # touch all statuses that already exist and that we're about to update
+    Status.where(uri: uris).should_fetch_replies.touch_all(:fetched_replies_at)
+
+    # Reject all statuses that we already have in the db
+    uris = (uris - dont_update).take(MAX_REPLIES)
+
+    Rails.logger.debug { "FetchAllRepliesService - #{@collection_or_uri}: Fetching filtered statuses: #{uris}" }
+    uris
+  end
+end

app/services/activitypub/fetch_replies_service.rb

@@ -3,11 +3,15 @@
 class ActivityPub::FetchRepliesService < BaseService
   include JsonLdHelper
 
-  def call(parent_status, collection_or_uri, allow_synchronous_requests: true, request_id: nil)
+  # Limit of fetched replies
+  MAX_REPLIES = 5
+
+  def call(parent_status, collection_or_uri, allow_synchronous_requests: true, request_id: nil, filter_by_host: true)
     @account = parent_status.account
     @allow_synchronous_requests = allow_synchronous_requests
+    @filter_by_host = filter_by_host
 
-    @items = collection_items(collection_or_uri)
+    @items, = collection_items(collection_or_uri)
     return if @items.nil?
 
     FetchReplyWorker.push_bulk(filtered_replies) { |reply_uri| [reply_uri, { 'request_id' => request_id }] }
@@ -17,25 +21,39 @@ class ActivityPub::FetchRepliesService < BaseService
 
   private
 
-  def collection_items(collection_or_uri)
+  def collection_items(collection_or_uri, max_pages = nil)
     collection = fetch_collection(collection_or_uri)
     return unless collection.is_a?(Hash)
 
     collection = fetch_collection(collection['first']) if collection['first'].present?
     return unless collection.is_a?(Hash)
 
-    case collection['type']
-    when 'Collection', 'CollectionPage'
-      as_array(collection['items'])
-    when 'OrderedCollection', 'OrderedCollectionPage'
-      as_array(collection['orderedItems'])
+    all_items = []
+    n_pages = 1
+    while collection.is_a?(Hash)
+      items = case collection['type']
+              when 'Collection', 'CollectionPage'
+                collection['items']
+              when 'OrderedCollection', 'OrderedCollectionPage'
+                collection['orderedItems']
+              end
+
+      all_items.concat(as_array(items))
+
+      break if all_items.size >= MAX_REPLIES
+      break if !max_pages.nil? && n_pages >= max_pages
+
+      collection = collection['next'].present? ? fetch_collection(collection['next']) : nil
+      n_pages += 1
     end
+
+    [all_items, n_pages]
   end
 
   def fetch_collection(collection_or_uri)
     return collection_or_uri if collection_or_uri.is_a?(Hash)
     return unless @allow_synchronous_requests
-    return if non_matching_uri_hosts?(@account.uri, collection_or_uri)
+    return if @filter_by_host && non_matching_uri_hosts?(@account.uri, collection_or_uri)
 
     # NOTE: For backward compatibility reasons, Mastodon signs outgoing
     # queries incorrectly by default.
@@ -54,10 +72,14 @@ class ActivityPub::FetchRepliesService < BaseService
   end
 
   def filtered_replies
-    # Only fetch replies to the same server as the original status to avoid
-    # amplification attacks.
+    if @filter_by_host
+      # Only fetch replies to the same server as the original status to avoid
+      # amplification attacks.
 
-    # Also limit to 5 fetched replies to limit potential for DoS.
-    @items.map { |item| value_or_id(item) }.reject { |uri| non_matching_uri_hosts?(@account.uri, uri) }.take(5)
+      # Also limit to 5 fetched replies to limit potential for DoS.
+      @items.map { |item| value_or_id(item) }.reject { |uri| non_matching_uri_hosts?(@account.uri, uri) }.take(MAX_REPLIES)
+    else
+      @items.map { |item| value_or_id(item) }.take(MAX_REPLIES)
+    end
   end
 end

app/workers/activitypub/fetch_all_replies_worker.rb

@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+# Fetch all replies to a status, querying recursively through
+# ActivityPub replies collections, fetching any statuses that
+# we either don't already have or we haven't checked for new replies
+# in the Status::FETCH_REPLIES_DEBOUNCE interval
+class ActivityPub::FetchAllRepliesWorker
+  include Sidekiq::Worker
+  include ExponentialBackoff
+  include JsonLdHelper
+
+  sidekiq_options queue: 'pull', retry: 3
+
+  # Global max replies to fetch per request (all replies, recursively)
+  MAX_REPLIES = (ENV['FETCH_REPLIES_MAX_GLOBAL'] || 1000).to_i
+  MAX_PAGES = (ENV['FETCH_REPLIES_MAX_PAGES'] || 500).to_i
+
+  def perform(parent_status_id, options = {})
+    @parent_status = Status.find(parent_status_id)
+    return unless @parent_status.should_fetch_replies?
+
+    @parent_status.touch(:fetched_replies_at)
+    Rails.logger.debug { "FetchAllRepliesWorker - #{@parent_status.uri}: Fetching all replies for status: #{@parent_status}" }
+
+    uris_to_fetch, n_pages = get_replies(@parent_status.uri, MAX_PAGES, options)
+    return if uris_to_fetch.nil?
+
+    fetched_uris = uris_to_fetch.clone.to_set
+
+    until uris_to_fetch.empty? || fetched_uris.length >= MAX_REPLIES || n_pages >= MAX_PAGES
+      next_reply = uris_to_fetch.pop
+      next if next_reply.nil?
+
+      new_reply_uris, new_n_pages = get_replies(next_reply, MAX_PAGES - n_pages, options)
+      next if new_reply_uris.nil?
+
+      new_reply_uris = new_reply_uris.reject { |uri| fetched_uris.include?(uri) }
+
+      uris_to_fetch.concat(new_reply_uris)
+      fetched_uris = fetched_uris.merge(new_reply_uris)
+      n_pages += new_n_pages
+    end
+
+    Rails.logger.debug { "FetchAllRepliesWorker - #{parent_status_id}: fetched #{fetched_uris.length} replies" }
+    fetched_uris
+  end
+
+  private
+
+  def get_replies(status_uri, max_pages, options = {})
+    replies_collection_or_uri = get_replies_uri(status_uri)
+    return if replies_collection_or_uri.nil?
+
+    ActivityPub::FetchAllRepliesService.new.call(replies_collection_or_uri, max_pages, **options.deep_symbolize_keys)
+  end
+
+  def get_replies_uri(parent_status_uri)
+    begin
+      json_status = fetch_resource(parent_status_uri, true)
+      if json_status.nil?
+        Rails.logger.debug { "FetchAllRepliesWorker - #{@parent_status.uri}: Could not get replies URI for #{parent_status_uri}, returned nil" }
+        nil
+      elsif !json_status.key?('replies')
+        Rails.logger.debug { "FetchAllRepliesWorker - #{@parent_status.uri}: No replies collection found in ActivityPub object: #{json_status}" }
+        nil
+      else
+        json_status['replies']
+      end
+    rescue => e
+      Rails.logger.error { "FetchAllRepliesWorker - #{@parent_status.uri}: Caught exception while resolving replies URI #{parent_status_uri}: #{e} - #{e.message}" }
+      # Raise if we can't get the collection for top-level status to trigger retry
+      raise e if parent_status_uri == @parent_status.uri
+
+      nil
+    end
+  end
+end

db/migrate/20240918233930_add_fetched_replies_at_to_status.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddFetchedRepliesAtToStatus < ActiveRecord::Migration[7.1]
+  def change
+    add_column :statuses, :fetched_replies_at, :datetime, null: true
+  end
+end

db/schema.rb

@@ -1052,6 +1052,7 @@ ActiveRecord::Schema[7.2].define(version: 2024_12_16_224825) do
     t.datetime "edited_at", precision: nil
     t.boolean "trendable"
     t.bigint "ordered_media_attachment_ids", array: true
+    t.datetime "fetched_replies_at"
     t.index ["account_id", "id", "visibility", "updated_at"], name: "index_statuses_20190820", order: { id: :desc }, where: "(deleted_at IS NULL)"
     t.index ["account_id"], name: "index_statuses_on_account_id"
     t.index ["deleted_at"], name: "index_statuses_on_deleted_at", where: "(deleted_at IS NOT NULL)"

spec/services/activitypub/fetch_all_replies_service_spec.rb

@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe ActivityPub::FetchAllRepliesService do
+  subject { described_class.new }
+
+  let(:actor)          { Fabricate(:account, domain: 'example.com', uri: 'http://example.com/account') }
+  let(:status)         { Fabricate(:status, account: actor) }
+  let(:collection_uri) { 'http://example.com/replies/1' }
+
+  let(:items) do
+    [
+      'http://example.com/self-reply-1',
+      'http://example.com/self-reply-2',
+      'http://example.com/self-reply-3',
+      'http://other.com/other-reply-1',
+      'http://other.com/other-reply-2',
+      'http://other.com/other-reply-3',
+      'http://example.com/self-reply-4',
+      'http://example.com/self-reply-5',
+      'http://example.com/self-reply-6',
+    ]
+  end
+
+  let(:payload) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      type: 'Collection',
+      id: collection_uri,
+      items: items,
+    }.with_indifferent_access
+  end
+
+  describe '#call' do
+    it 'fetches more than the default maximum and from multiple domains' do
+      allow(FetchReplyWorker).to receive(:push_bulk)
+
+      subject.call(payload)
+
+      expect(FetchReplyWorker).to have_received(:push_bulk).with(%w(http://example.com/self-reply-1 http://example.com/self-reply-2 http://example.com/self-reply-3 http://other.com/other-reply-1 http://other.com/other-reply-2 http://other.com/other-reply-3 http://example.com/self-reply-4
+                                                                    http://example.com/self-reply-5 http://example.com/self-reply-6))
+    end
+
+    context 'with a recent status' do
+      before do
+        Fabricate(:status, uri: 'http://example.com/self-reply-2', fetched_replies_at: 1.second.ago, local: false)
+      end
+
+      it 'skips statuses that have been updated recently' do
+        allow(FetchReplyWorker).to receive(:push_bulk)
+
+        subject.call(payload)
+
+        expect(FetchReplyWorker).to have_received(:push_bulk).with(%w(http://example.com/self-reply-1 http://example.com/self-reply-3 http://other.com/other-reply-1 http://other.com/other-reply-2 http://other.com/other-reply-3 http://example.com/self-reply-4 http://example.com/self-reply-5 http://example.com/self-reply-6))
+      end
+    end
+
+    context 'with an old status' do
+      before do
+        Fabricate(:status, uri: 'http://other.com/other-reply-1', fetched_replies_at: 1.year.ago, created_at: 1.year.ago, account: actor)
+      end
+
+      it 'updates the time that fetched statuses were last fetched' do
+        allow(FetchReplyWorker).to receive(:push_bulk)
+
+        subject.call(payload)
+
+        expect(Status.find_by(uri: 'http://other.com/other-reply-1').fetched_replies_at).to be >= 1.minute.ago
+      end
+    end
+  end
+end

spec/workers/activitypub/fetch_all_replies_worker_spec.rb

@@ -0,0 +1,280 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe ActivityPub::FetchAllRepliesWorker do
+  subject { described_class.new }
+
+  let(:top_items) do
+    [
+      'http://example.com/self-reply-1',
+      'http://other.com/other-reply-2',
+      'http://example.com/self-reply-3',
+    ]
+  end
+
+  let(:top_items_paged) do
+    [
+      'http://example.com/self-reply-4',
+      'http://other.com/other-reply-5',
+      'http://example.com/self-reply-6',
+    ]
+  end
+
+  let(:nested_items) do
+    [
+      'http://example.com/nested-self-reply-1',
+      'http://other.com/nested-other-reply-2',
+      'http://example.com/nested-self-reply-3',
+    ]
+  end
+
+  let(:nested_items_paged) do
+    [
+      'http://example.com/nested-self-reply-4',
+      'http://other.com/nested-other-reply-5',
+      'http://example.com/nested-self-reply-6',
+    ]
+  end
+
+  let(:all_items) do
+    top_items + top_items_paged + nested_items + nested_items_paged
+  end
+
+  let(:top_note_uri) do
+    'http://example.com/top-post'
+  end
+
+  let(:top_collection_uri) do
+    'http://example.com/top-post/replies'
+  end
+
+  # The reply uri that has the nested replies under it
+  let(:reply_note_uri) do
+    'http://other.com/other-reply-2'
+  end
+
+  # The collection uri of nested replies
+  let(:reply_collection_uri) do
+    'http://other.com/other-reply-2/replies'
+  end
+
+  let(:replies_top) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      id: top_collection_uri,
+      type: 'Collection',
+      items: top_items + top_items_paged,
+    }
+  end
+
+  let(:replies_nested) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      id: reply_collection_uri,
+      type: 'Collection',
+      items: nested_items + nested_items_paged,
+    }
+  end
+
+  # The status resource for the top post
+  let(:top_object) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      id: top_note_uri,
+      type: 'Note',
+      content: 'Lorem ipsum',
+      replies: replies_top,
+      attributedTo: 'https://example.com',
+    }
+  end
+
+  # The status resource that has the uri to the replies collection
+  let(:reply_object) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      id: reply_note_uri,
+      type: 'Note',
+      content: 'Lorem ipsum',
+      replies: replies_nested,
+      attributedTo: 'https://other.com',
+    }
+  end
+
+  let(:empty_object) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      id: 'https://example.com/empty',
+      type: 'Note',
+      content: 'Lorem ipsum',
+      replies: [],
+      attributedTo: 'https://example.com',
+    }
+  end
+
+  let(:account) { Fabricate(:account, domain: 'example.com') }
+  let(:status) do
+    Fabricate(
+      :status,
+      account: account,
+      uri: top_note_uri,
+      created_at: 1.day.ago - Status::FetchRepliesConcern::CREATED_RECENTLY_DEBOUNCE
+    )
+  end
+
+  before do
+    allow(FetchReplyWorker).to receive(:push_bulk)
+    all_items.each do |item|
+      next if [top_note_uri, reply_note_uri].include? item
+
+      stub_request(:get, item).to_return(status: 200, body: Oj.dump(empty_object), headers: { 'Content-Type': 'application/activity+json' })
+    end
+
+    stub_request(:get, top_note_uri).to_return(status: 200, body: Oj.dump(top_object), headers: { 'Content-Type': 'application/activity+json' })
+    stub_request(:get, reply_note_uri).to_return(status: 200, body: Oj.dump(reply_object), headers: { 'Content-Type': 'application/activity+json' })
+  end
+
+  shared_examples 'fetches all replies' do
+    it 'fetches statuses recursively' do
+      got_uris = subject.perform(status.id)
+      expect(got_uris).to match_array(all_items)
+    end
+
+    it 'respects the maximum limits set by not recursing after the max is reached' do
+      stub_const('ActivityPub::FetchAllRepliesWorker::MAX_REPLIES', 5)
+      got_uris = subject.perform(status.id)
+      expect(got_uris).to match_array(top_items + top_items_paged)
+    end
+  end
+
+  describe 'perform' do
+    context 'when the payload is a Note with replies as a Collection of inlined replies' do
+      it_behaves_like 'fetches all replies'
+    end
+
+    context 'when the payload is a Note with replies as a URI to a Collection' do
+      let(:top_object) do
+        {
+          '@context': 'https://www.w3.org/ns/activitystreams',
+          id: top_note_uri,
+          type: 'Note',
+          content: 'Lorem ipsum',
+          replies: top_collection_uri,
+          attributedTo: 'https://example.com',
+        }
+      end
+      let(:reply_object) do
+        {
+          '@context': 'https://www.w3.org/ns/activitystreams',
+          id: reply_note_uri,
+          type: 'Note',
+          content: 'Lorem ipsum',
+          replies: reply_collection_uri,
+          attributedTo: 'https://other.com',
+        }
+      end
+
+      before do
+        stub_request(:get, top_collection_uri).to_return(status: 200, body: Oj.dump(replies_top), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, reply_collection_uri).to_return(status: 200, body: Oj.dump(replies_nested), headers: { 'Content-Type': 'application/activity+json' })
+      end
+
+      it_behaves_like 'fetches all replies'
+    end
+
+    context 'when the payload is a Note with replies as a paginated collection' do
+      let(:top_page_2_uri) do
+        "#{top_collection_uri}/2"
+      end
+
+      let(:reply_page_2_uri) do
+        "#{reply_collection_uri}/2"
+      end
+
+      let(:top_object) do
+        {
+          '@context': 'https://www.w3.org/ns/activitystreams',
+          id: top_note_uri,
+          type: 'Note',
+          content: 'Lorem ipsum',
+          replies: {
+            type: 'Collection',
+            id: top_collection_uri,
+            first: {
+              type: 'CollectionPage',
+              partOf: top_collection_uri,
+              items: top_items,
+              next: top_page_2_uri,
+            },
+          },
+          attributedTo: 'https://example.com',
+        }
+      end
+      let(:reply_object) do
+        {
+          '@context': 'https://www.w3.org/ns/activitystreams',
+          id: reply_note_uri,
+          type: 'Note',
+          content: 'Lorem ipsum',
+          replies: {
+            type: 'Collection',
+            id: reply_collection_uri,
+            first: {
+              type: 'CollectionPage',
+              partOf: reply_collection_uri,
+              items: nested_items,
+              next: reply_page_2_uri,
+            },
+          },
+          attributedTo: 'https://other.com',
+        }
+      end
+
+      let(:top_page_two) do
+        {
+          type: 'CollectionPage',
+          id: top_page_2_uri,
+          partOf: top_collection_uri,
+          items: top_items_paged,
+        }
+      end
+
+      let(:reply_page_two) do
+        {
+          type: 'CollectionPage',
+          id: reply_page_2_uri,
+          partOf: reply_collection_uri,
+          items: nested_items_paged,
+        }
+      end
+
+      before do
+        stub_request(:get, top_page_2_uri).to_return(status: 200, body: Oj.dump(top_page_two), headers: { 'Content-Type': 'application/activity+json' })
+        stub_request(:get, reply_page_2_uri).to_return(status: 200, body: Oj.dump(reply_page_two), headers: { 'Content-Type': 'application/activity+json' })
+      end
+
+      it_behaves_like 'fetches all replies'
+
+      it 'limits by max pages' do
+        stub_const('ActivityPub::FetchAllRepliesWorker::MAX_PAGES', 3)
+        got_uris = subject.perform(status.id)
+        expect(got_uris).to match_array(top_items + top_items_paged + nested_items)
+      end
+    end
+
+    context 'when replies should not be fetched' do
+      # ensure that we should not fetch by setting the status to be created in the debounce window
+      let(:status) { Fabricate(:status, account: account, uri: top_note_uri, created_at: DateTime.now) }
+
+      before do
+        stub_const('Status::FetchRepliesConcern::CREATED_RECENTLY_DEBOUNCE', 1.week)
+      end
+
+      it 'returns nil without fetching' do
+        got_uris = subject.perform(status.id)
+        expect(got_uris).to be_nil
+        assert_not_requested :get, top_note_uri
+      end
+    end
+  end
+end