Bump net-ldap from 0.17.1 to 0.18.0

Bumps [net-ldap](https://github.com/ruby-ldap/ruby-net-ldap) from 0.17.1 to 0.18.0.
- [Release notes](https://github.com/ruby-ldap/ruby-net-ldap/releases)
- [Changelog](https://github.com/ruby-ldap/ruby-net-ldap/blob/master/History.rdoc)
- [Commits](https://github.com/ruby-ldap/ruby-net-ldap/compare/v0.17.1...v0.18.0)

---
updated-dependencies:
- dependency-name: net-ldap
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -37,7 +37,7 @@ group :pam_authentication, optional: true do
   gem 'devise_pam_authenticatable2', '~> 9.2'
 end
 
-gem 'net-ldap', '~> 0.17'
+gem 'net-ldap', '~> 0.18'
 gem 'omniauth-cas', '~> 2.0'
 gem 'omniauth-saml', '~> 1.10'
 gem 'gitlab-omniauth-openid-connect', '~>0.10.0', require: 'omniauth_openid_connect'
@@ -155,3 +155,5 @@ gem 'concurrent-ruby', require: false
 gem 'connection_pool', require: false
 gem 'xorcist', '~> 1.1'
 gem 'cocoon', '~> 1.2'
+
+gem 'random_name_generator'

Gemfile.lock

@@ -407,7 +407,7 @@ GEM
     msgpack (1.5.4)
     multi_json (1.15.0)
     multipart-post (2.1.1)
-    net-ldap (0.17.1)
+    net-ldap (0.18.0)
     net-scp (4.0.0.rc1)
       net-ssh (>= 2.6.5, < 8.0.0)
     net-ssh (7.0.1)
@@ -535,6 +535,7 @@ GEM
       thor (~> 1.0)
     rainbow (3.1.1)
     rake (13.0.6)
+    random_name_generator (2.0.1)
     rdf (3.2.9)
       link_header (~> 0.0, >= 0.0.8)
     rdf-normalize (0.5.0)
@@ -792,7 +793,7 @@ DEPENDENCIES
   memory_profiler
   microformats (~> 4.4)
   mime-types (~> 3.4.1)
-  net-ldap (~> 0.17)
+  net-ldap (~> 0.18)
   nokogiri (~> 1.13)
   nsa (~> 0.2)
   oj (~> 3.13)
@@ -820,6 +821,7 @@ DEPENDENCIES
   rails-controller-testing (~> 1.0)
   rails-i18n (~> 6.0)
   rails-settings-cached (~> 0.6)
+  random_name_generator
   rdf-normalize (~> 0.5)
   redcarpet (~> 3.5)
   redis (~> 4.5)
@@ -855,3 +857,9 @@ DEPENDENCIES
   webpacker (~> 5.4)
   webpush!
   xorcist (~> 1.1)
+
+RUBY VERSION
+   ruby 3.0.4p208
+
+BUNDLED WITH
+   2.2.33

app/controllers/activitypub/inboxes_controller.rb

@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+require 'redis'
 
 class ActivityPub::InboxesController < ActivityPub::BaseController
   include SignatureVerification
@@ -9,6 +10,10 @@ class ActivityPub::InboxesController < ActivityPub::BaseController
   before_action :require_actor_signature!
   skip_before_action :authenticate_user!
 
+  def initialize
+    @activity_log_publisher = ActivityLogPublisher.new
+  end
+
   def create
     upgrade_account
     process_collection_synchronization
@@ -71,6 +76,16 @@ class ActivityPub::InboxesController < ActivityPub::BaseController
   end
 
   def process_payload
+    raw_signature = request.headers['Signature']
+    tree          = SignatureParamsParser.new.parse(raw_signature)
+    signature_params = SignatureParamsTransformer.new.apply(tree)
+
+    sender = actor_from_key_id(signature_params['keyId'])
+
+    event = ActivityLogEvent.new('inbound', sender.uri, "https://#{Rails.configuration.x.web_domain}#{request.path}", Oj.load(body, mode: :strict))
+
+    @activity_log_publisher.publish(event)
+
     ActivityPub::ProcessingWorker.perform_async(signed_request_actor.id, body, @account&.id, signed_request_actor.class.name)
   end
 end

app/controllers/api/v1/activity_log_controller.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class Api::V1::ActivityLogController < Api::BaseController
+  include ActionController::Live
+
+  before_action :require_user!
+
+  rescue_from ArgumentError do |e|
+    render json: { error: e.to_s }, status: 422
+  end
+
+  def show
+    response.headers['Content-Type'] = 'text/event-stream'
+    # hack to avoid computing Etag, which delays sending of data
+    response.headers['Last-Modified'] = Time.now.httpdate
+
+    # adapted from https://blog.chumakoff.com/en/posts/rails_sse_rack_hijacking_api
+    response.headers["rack.hijack"] = proc do |stream|
+      ActivityLogger.register(current_account.username, SSE.new(stream))
+    end
+
+    head :ok
+  end
+end

app/controllers/api/v1/json_ld_controller.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require "faraday"
+
+class Api::V1::JsonLdController < Api::BaseController
+  include ActionController::Live
+
+  rescue_from ArgumentError do |e|
+    render json: { error: e.to_s }, status: 422
+  end
+
+  def show
+    url = params[:url]
+
+    request.env['rack.hijack'].call
+    io = request.env['rack.hijack_io']
+    Thread.new {
+      begin
+        conn = Faraday::Connection.new
+        conn.options.timeout = 5
+
+        api_response = conn.get(url, nil, {'Accept' => 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'})
+
+        max_redirects = 5
+        while api_response.status == 301 || api_response.status == 302 and max_redirects > 0 do
+          api_response = conn.get(api_response.headers['Location'], nil, {'Accept' => 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'})
+          max_redirects -= 1
+        end
+
+        io.write("HTTP/1.1 #{api_response.status}\r\n")
+        io.write("Content-Type: #{api_response.headers['Content-Type']}\r\n")
+        io.write("Access-Control-Allow-Origin: *\r\n")
+        io.write("Connection: close\r\n")
+        io.write("\r\n")
+        io.write(api_response.body)
+      rescue
+        io.write("HTTP/1.1 500\r\n")
+        io.write("Access-Control-Allow-Origin: *\r\n")
+        io.write("Connection: close\r\n")
+        io.write("\r\n")
+      ensure
+        io.close
+      end
+    }
+  end
+end

app/controllers/application_controller.rb

@@ -61,7 +61,7 @@ class ApplicationController < ActionController::Base
   end
 
   def after_sign_out_path_for(_resource_or_scope)
-    new_user_session_path
+    "/auth/sign_up"
   end
 
   protected

app/controllers/auth/registrations_controller.rb

@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+require 'random_name_generator'
+require 'securerandom'
+
 class Auth::RegistrationsController < Devise::RegistrationsController
   include RegistrationSpamConcern
 
@@ -45,6 +48,21 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   end
 
   def build_resource(hash = nil)
+
+    # hack to always use auto-generated usernames and passwords
+    if !hash.nil?
+      username = generate_name
+      password = SecureRandom.hex
+
+      hash["account_attributes"] = {
+        "username": username.parameterize(separator: '_'),
+        "display_name": username
+      }
+      hash["email"] = "#{hash["account_attributes"]["username"]}@#{Rails.configuration.x.web_domain}"
+      hash["password"] = password
+      hash["password_confirmation"] = password
+    end
+
     super(hash)
 
     resource.locale                 = I18n.locale
@@ -62,7 +80,9 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   end
 
   def after_sign_up_path_for(_resource)
-    auth_setup_path
+    # Hack to automatically visit the confirmation link after successful sign-up.
+    # This way we can use the default configuration but still get away without an email server.
+    "/auth/confirmation?confirmation_token=#{@user.confirmation_token}"
   end
 
   def after_sign_in_path_for(_resource)
@@ -156,4 +176,16 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   def set_cache_headers
     response.headers['Cache-Control'] = 'no-cache, no-store, max-age=0, must-revalidate'
   end
+
+  @@first_name_generator = RandomNameGenerator.new(File.new("#{File.dirname(__FILE__)}/roman.txt"))
+  @@last_name_generator = RandomNameGenerator.new(RandomNameGenerator::FANTASY)
+
+  def generate_name
+    # When there is a name collision, the user will be shown
+    # "Something isn't quite right yet! Please review 2 errors below"
+    # When they sign up again, it will most probably succeed (since there is no collision anymore)
+    # While this isn't the best UX, it's only a minor issue
+    # (collisions happen after > 1k of users and there's an easy fix) # so not worth fixing for now
+    "#{@@first_name_generator.compose(3)} #{@@last_name_generator.compose(3)}"
+  end
 end

app/controllers/auth/roman.txt

@@ -0,0 +1,44 @@
+-a
+-al
+-au +c
+-an
+-ba
+-be
+-bi
+-br +v
+-da
+-di
+-do
+-du
+-e
+-eu +c
+-fa
+bi
+be
+bo
+bu
+nul +v
+gu
+da
+au +c -c
+fri
+gus
++tus
++ta
++lus
++la
++lius
++lia
++nus
++na
++es
++ius -c
++ia -c
++cus
++ca
++tor
++cio
++cia
++tin
++tia
++ssia -v

app/controllers/home_controller.rb

@@ -6,7 +6,9 @@ class HomeController < ApplicationController
   before_action :set_instance_presenter
 
   def index
-    expires_in 0, public: true unless user_signed_in?
+    if !user_signed_in?
+      redirect_to "/auth/sign_up"
+    end
   end
 
   private

app/javascript/mastodon/actions/activity_log.js

@@ -0,0 +1,11 @@
+export const ACTIVITY_LOG_RESET ='ACTIVITY_LOG_RESET';
+export const ACTIVITY_LOG_ADD = 'ACTIVITY_LOG_ADD';
+
+export const resetActivityLog = () => ({
+  type: ACTIVITY_LOG_RESET,
+});
+
+export const addActivityLog = value => ({
+  type: ACTIVITY_LOG_ADD,
+  value,
+});

app/javascript/mastodon/actions/activitypub_explorer.js

@@ -0,0 +1,12 @@
+export const ACTIVITYPUB_EXPLORER_DATA ='ACTIVITYPUB_EXPLORER_DATA';
+export const ACTIVITYPUB_EXPLORER_URL ='ACTIVITYPUB_EXPLORER_URL';
+
+export const setExplorerData = (value) => ({
+  type: ACTIVITYPUB_EXPLORER_DATA,
+  value,
+});
+
+export const setExplorerUrl = (value) => ({
+  type: ACTIVITYPUB_EXPLORER_URL,
+  value,
+});

app/javascript/mastodon/containers/mastodon.js

@@ -13,6 +13,7 @@ import { connectUserStream } from 'mastodon/actions/streaming';
 import ErrorBoundary from 'mastodon/components/error_boundary';
 import initialState, { title as siteTitle } from 'mastodon/initial_state';
 import { getLocale } from 'mastodon/locales';
+import { addActivityLog } from 'mastodon/actions/activity_log';
 
 const { localeData, messages } = getLocale();
 addLocaleData(localeData);
@@ -59,6 +60,14 @@ export default class Mastodon extends React.PureComponent {
   componentDidMount() {
     if (this.identity.signedIn) {
       this.disconnect = store.dispatch(connectUserStream());
+
+      this.eventSource = new EventSource('/api/v1/activity_log');
+      this.eventSource.onmessage = (event) => {
+        const parsed = JSON.parse(event.data);
+        if (parsed.type !== 'keep-alive') {
+          store.dispatch(addActivityLog(parsed));
+        }
+      };
     }
   }
 
@@ -66,6 +75,7 @@ export default class Mastodon extends React.PureComponent {
     if (this.disconnect) {
       this.disconnect();
       this.disconnect = null;
+      this.eventSource.close();
     }
   }
 

app/javascript/mastodon/features/activity_log/index.js

@@ -0,0 +1,112 @@
+import React from 'react';
+import { connect } from 'react-redux';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+import { FormattedMessage } from 'react-intl';
+import PropTypes from 'prop-types';
+import Column from 'mastodon/components/column';
+import ColumnHeader from 'mastodon/components/column_header';
+import { HotKeys } from 'react-hotkeys';
+import { setExplorerData, setExplorerUrl } from 'mastodon/actions/activitypub_explorer';
+import DismissableBanner from 'mastodon/components/dismissable_banner';
+
+import { ActivityPubVisualization } from 'activitypub-visualization';
+
+const mapStateToProps = (state) => {
+  return {
+    logs: state.getIn(['activity_log', 'logs']),
+  };
+};
+
+export default @connect(mapStateToProps)
+class ActivityLog extends ImmutablePureComponent {
+
+  static contextTypes = {
+    router: PropTypes.object,
+  };
+
+  static propTypes = {
+    dispatch: PropTypes.func.isRequired,
+    multiColumn: PropTypes.bool,
+  };
+
+  handleHeaderClick = () => {
+    this.column.scrollTop();
+  }
+
+  setRef = c => {
+    this.column = c;
+  }
+
+  render() {
+
+    const { dispatch, logs, multiColumn } = this.props;
+
+    const darkMode = !(document.body && document.body.classList.contains('theme-mastodon-light'));
+
+    // hijack the toggleHidden shortcut to copy the logs to clipbaord
+    const handlers = {
+      toggleHidden: () => navigator.clipboard.writeText(JSON.stringify(logs, null, 2)),
+    };
+
+    const Content = () => {
+      if (logs.length > 0) {
+        return ( <HotKeys handlers={handlers}>
+          <div className={`${darkMode ? 'dark' : ''}`} style={{height: '100%'}}>
+            <ActivityPubVisualization
+              logs={logs}
+              clickableLinks
+              onLinkClick={(url) => {
+                dispatch(setExplorerUrl(url));
+                this.context.router.history.push('/activitypub_explorer');
+              }}
+              showExplorerLink
+              onExplorerLinkClick={(data) => {
+                dispatch(setExplorerData(data));
+                this.context.router.history.push('/activitypub_explorer');
+              }}
+            />
+          </div>
+        </HotKeys>) } else {
+          return (<div className='empty-column-indicator'>
+            <FormattedMessage id='empty_column.activity_log' defaultMessage='The Activity Log is empty. Interact with accounts on other instances to trigger activities. You can find more information on my {blog}.'
+              values={{
+                blog: <a className='blog-link' href='//seb.jambor.dev/'>blog</a>,
+              }}
+            />
+          </div>)
+        }
+    }
+
+    return (
+      <Column bindToDocument={!multiColumn} ref={this.setRef} label='Activity Log'>
+        <ColumnHeader
+          icon='comments'
+          title='Activity Log'
+          onClick={this.handleHeaderClick}
+          multiColumn={multiColumn}
+        />
+
+        <DismissableBanner id='activity_log'>
+          <p>
+            <FormattedMessage
+              id='dismissable_banner.activity_log_information'
+              defaultMessage='When you interact with another instance (for example, follow an account on another instance), the resulting Activities will be shown here. You can find more information on my {blog}.'
+              values={{
+                blog: <a className='blog-link' href='//seb.jambor.dev/'>blog</a>,
+              }}
+            />
+          </p>
+          <p style={{ paddingTop: '5px' }}>
+            <FormattedMessage
+              id='dismissable_banner.activity_log_clear'
+              defaultMessage='Note: Activities will only be logged while Mastodon is open. When you navigate elsewhere or reload the page, the log will be cleared.'
+            />
+          </p>
+        </DismissableBanner>
+
+        <Content />
+      </Column>
+    );
+  }
+
+}

app/javascript/mastodon/features/activitypub_explorer/index.js

@@ -0,0 +1,85 @@
+import React from 'react';
+import { connect } from 'react-redux';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+import { FormattedMessage } from 'react-intl';
+import PropTypes from 'prop-types';
+import Column from 'mastodon/components/column';
+import ColumnHeader from 'mastodon/components/column_header';
+import DismissableBanner from 'mastodon/components/dismissable_banner';
+import { setExplorerData, setExplorerUrl } from 'mastodon/actions/activitypub_explorer';
+
+import { ActivityPubExplorer as Explorer } from 'activitypub-visualization';
+
+
+const mapStateToProps = (state) => {
+  return {
+    data: state.getIn(['activitypub_explorer', 'data']),
+    url: state.getIn(['activitypub_explorer', 'url']),
+  };
+};
+
+export default @connect(mapStateToProps)
+class ActivityPubExplorer extends ImmutablePureComponent {
+
+  static propTypes = {
+    dispatch: PropTypes.func.isRequired,
+    multiColumn: PropTypes.bool,
+  };
+
+  handleHeaderClick = () => {
+    this.column.scrollTop();
+  }
+
+  setRef = c => {
+    this.column = c;
+  }
+
+  componentWillUnmount () {
+    // clear explorer data on unbound so that we start with a clean slate on next navigation
+    this.props.dispatch(setExplorerData(null));
+    this.props.dispatch(setExplorerUrl(''));
+  }
+
+  render() {
+
+    const { data, url, multiColumn } = this.props;
+
+    const darkMode = !(document.body && document.body.classList.contains('theme-mastodon-light'));
+
+    return (
+      <Column bindToDocument={!multiColumn} ref={this.setRef} label='ActivityPub Explorer'>
+        <ColumnHeader
+          icon='wpexplorer'
+          title='ActivityPub Explorer'
+          onClick={this.handleHeaderClick}
+          multiColumn={multiColumn}
+        />
+
+        <DismissableBanner id='activity_log'>
+          <p>
+            <FormattedMessage
+              id='dismissable_banner.activity_pub_explorer_information'
+              defaultMessage='The AcivityPub Explorer provides a convenient way to browse through ActivityPub data. Click on any {https} URL in the returned JSON to fetch the corresponding data. You can find more information on my {blog}.'
+              values={{
+                blog: <a className='blog-link' href='//seb.jambor.dev/'>blog</a>,
+                https: <code>https://</code>,
+              }}
+            />
+          </p>
+        </DismissableBanner>
+
+        <div className={`${darkMode ? 'dark' : ''}`}>
+          <Explorer
+            fetchMethod={async (url) =>
+              fetch('/api/v1/json_ld?' + new URLSearchParams({ url }).toString())
+            }
+            initialValue={data}
+            initialUrl={url}
+          />
+        </div>
+      </Column>
+    );
+  }
+
+}
+

app/javascript/mastodon/features/compose/components/action_bar.js

@@ -9,6 +9,7 @@ const messages = defineMessages({
   pins: { id: 'navigation_bar.pins', defaultMessage: 'Pinned posts' },
   preferences: { id: 'navigation_bar.preferences', defaultMessage: 'Preferences' },
   follow_requests: { id: 'navigation_bar.follow_requests', defaultMessage: 'Follow requests' },
+  activity_log: { id: 'navigation_bar.activity_log', defaultMessage: 'Activity log' },
   favourites: { id: 'navigation_bar.favourites', defaultMessage: 'Favourites' },
   lists: { id: 'navigation_bar.lists', defaultMessage: 'Lists' },
   blocks: { id: 'navigation_bar.blocks', defaultMessage: 'Blocked users' },
@@ -45,6 +46,7 @@ class ActionBar extends React.PureComponent {
     menu.push({ text: intl.formatMessage(messages.favourites), to: '/favourites' });
     menu.push({ text: intl.formatMessage(messages.bookmarks), to: '/bookmarks' });
     menu.push({ text: intl.formatMessage(messages.lists), to: '/lists' });
+    menu.push({ text: intl.formatMessage(messages.activity_log), to: '/activity_log' });
     menu.push(null);
     menu.push({ text: intl.formatMessage(messages.mutes), to: '/mutes' });
     menu.push({ text: intl.formatMessage(messages.blocks), to: '/blocks' });

app/javascript/mastodon/features/keyboard_shortcuts/index.js

@@ -158,6 +158,10 @@ class KeyboardShortcuts extends ImmutablePureComponent {
                 <td><kbd>g</kbd>+<kbd>r</kbd></td>
                 <td><FormattedMessage id='keyboard_shortcuts.requests' defaultMessage='to open follow requests list' /></td>
               </tr>
+              <tr>
+                <td><kbd>g</kbd>+<kbd>a</kbd></td>
+                <td><FormattedMessage id='keyboard_shortcuts.activity_log' defaultMessage='to open activity log' /></td>
+              </tr>
               <tr>
                 <td><kbd>?</kbd></td>
                 <td><FormattedMessage id='keyboard_shortcuts.legend' defaultMessage='to display this legend' /></td>

app/javascript/mastodon/features/ui/components/navigation_panel.js

@@ -86,6 +86,10 @@ class NavigationPanel extends React.Component {
             <ColumnLink transparent to='/bookmarks' icon='bookmark' text={intl.formatMessage(messages.bookmarks)} />
             <ColumnLink transparent to='/lists' icon='list-ul' text={intl.formatMessage(messages.lists)} />
 
+            <ColumnLink transparent to='/activity_log' icon='comments' text='Activity Log' />
+
+            <ColumnLink transparent to='/activitypub_explorer' icon='wpexplorer' text='ActivityPub Explorer' />
+
             <ListPanel />
 
             <hr />

app/javascript/mastodon/features/ui/index.js

@@ -48,6 +48,8 @@ import {
   Mutes,
   PinnedStatuses,
   Lists,
+  ActivityLog,
+  ActivityPubExplorer,
   Directory,
   Explore,
   FollowRecommendations,
@@ -105,6 +107,8 @@ const keyMap = {
   goToBlocked: 'g b',
   goToMuted: 'g m',
   goToRequests: 'g r',
+  goToActivityLog: 'g a',
+  goToActivityPubExplorer: 'g e',
   toggleHidden: 'x',
   toggleSensitive: 'h',
   openMedia: 'e',
@@ -156,11 +160,7 @@ class SwitchingColumnsArea extends React.PureComponent {
     let redirect;
 
     if (signedIn) {
-      if (mobile) {
-        redirect = <Redirect from='/' to='/home' exact />;
-      } else {
-        redirect = <Redirect from='/' to='/getting-started' exact />;
-      }
+      redirect = <Redirect from='/' to='/activity_log' exact />;
     } else if (singleUserMode && owner && initialState?.accounts[owner]) {
       redirect = <Redirect from='/' to={`/@${initialState.accounts[owner].username}`} exact />;
     } else if (showTrends) {
@@ -218,6 +218,8 @@ class SwitchingColumnsArea extends React.PureComponent {
           <WrappedRoute path='/domain_blocks' component={DomainBlocks} content={children} />
           <WrappedRoute path='/mutes' component={Mutes} content={children} />
           <WrappedRoute path='/lists' component={Lists} content={children} />
+          <WrappedRoute path='/activity_log' component={ActivityLog} content={children} />
+          <WrappedRoute path='/activitypub_explorer' component={ActivityPubExplorer} content={children} />
 
           <Route component={BundleColumnError} />
         </WrappedSwitch>
@@ -387,12 +389,6 @@ class UI extends React.PureComponent {
       navigator.serviceWorker.addEventListener('message', this.handleServiceWorkerPostMessage);
     }
 
-    // On first launch, redirect to the follow recommendations page
-    if (signedIn && this.props.firstLaunch) {
-      this.context.router.history.replace('/start');
-      this.props.dispatch(closeOnboarding());
-    }
-
     if (signedIn) {
       this.props.dispatch(fetchMarkers());
       this.props.dispatch(expandHomeTimeline());
@@ -495,6 +491,14 @@ class UI extends React.PureComponent {
     this.context.router.history.push('/home');
   }
 
+  handleHotkeyGoToActivityLog = () => {
+    this.context.router.history.push('/activity_log');
+  }
+
+  handleHotkeyGoToActivityPubExplorer = () => {
+    this.context.router.history.push('/activitypub_explorer');
+  }
+
   handleHotkeyGoToNotifications = () => {
     this.context.router.history.push('/notifications');
   }
@@ -552,6 +556,8 @@ class UI extends React.PureComponent {
       focusColumn: this.handleHotkeyFocusColumn,
       back: this.handleHotkeyBack,
       goToHome: this.handleHotkeyGoToHome,
+      goToActivityLog: this.handleHotkeyGoToActivityLog,
+      goToActivityPubExplorer: this.handleHotkeyGoToActivityPubExplorer,
       goToNotifications: this.handleHotkeyGoToNotifications,
       goToLocal: this.handleHotkeyGoToLocal,
       goToFederated: this.handleHotkeyGoToFederated,

app/javascript/mastodon/features/ui/util/async-components.js

@@ -38,6 +38,14 @@ export function Lists () {
   return import(/* webpackChunkName: "features/lists" */'../../lists');
 }
 
+export function ActivityLog () {
+  return import(/* webpackChunkName: "features/activity_log" */'../../activity_log');
+}
+
+export function ActivityPubExplorer () {
+  return import(/* webpackChunkName: "features/activity_log" */'../../activitypub_explorer');
+}
+
 export function Status () {
   return import(/* webpackChunkName: "features/status" */'../../status');
 }

app/javascript/mastodon/reducers/activity_log.js

@@ -0,0 +1,17 @@
+import { Map as ImmutableMap } from 'immutable';
+import { ACTIVITY_LOG_ADD, ACTIVITY_LOG_RESET } from '../actions/activity_log';
+
+const initialState = ImmutableMap({
+  logs: [],
+});
+
+export default function activity_log(state = initialState, action) {
+  switch (action.type) {
+  case ACTIVITY_LOG_ADD:
+    return state.set('logs', [...state.get('logs'), action.value]);
+  case ACTIVITY_LOG_RESET:
+    return state.set('logs', []);
+  default:
+    return state;
+  }
+}

app/javascript/mastodon/reducers/activitypub_explorer.js

@@ -0,0 +1,18 @@
+import { Map as ImmutableMap } from 'immutable';
+import { ACTIVITYPUB_EXPLORER_DATA, ACTIVITYPUB_EXPLORER_URL } from '../actions/activitypub_explorer';
+
+const initialState = ImmutableMap({
+  data: null,
+  url: '',
+});
+
+export default function activitypub_explorer(state = initialState, action) {
+  switch (action.type) {
+  case ACTIVITYPUB_EXPLORER_DATA:
+    return state.set('data', action.value);
+  case ACTIVITYPUB_EXPLORER_URL:
+    return state.set('url', action.value);
+  default:
+    return state;
+  }
+}

app/javascript/mastodon/reducers/index.js

@@ -9,6 +9,8 @@ import user_lists from './user_lists';
 import domain_lists from './domain_lists';
 import accounts from './accounts';
 import accounts_counters from './accounts_counters';
+import activity_log from './activity_log';
+import activitypub_explorer from './activitypub_explorer';
 import statuses from './statuses';
 import relationships from './relationships';
 import settings from './settings';
@@ -43,6 +45,8 @@ import tags from './tags';
 
 const reducers = {
   announcements,
+  activity_log,
+  activitypub_explorer,
   dropdown_menu,
   timelines,
   meta,

app/javascript/styles/application.scss

@@ -23,3 +23,5 @@
 @import 'mastodon/dashboard';
 @import 'mastodon/rtl';
 @import 'mastodon/accessibility';
+
+@import 'activitypub-visualization';

app/javascript/styles/mastodon/components.scss

@@ -8608,3 +8608,14 @@ noscript {
     }
   }
 }
+
+a.blog-link {
+  color: $highlight-text-color;
+  text-decoration: none;
+
+  &:hover,
+  &:focus,
+  &:active {
+    text-decoration: underline;
+  }
+}

app/javascript/styles/mastodon/forms.scss

@@ -919,6 +919,17 @@ code {
       }
     }
   }
+
+  a {
+    color: $highlight-text-color;
+    text-decoration: underline;
+
+    &:hover,
+    &:active,
+    &:focus {
+      text-decoration: none;
+    }
+  }
 }
 
 .action-pagination {

app/lib/activity_log_audience_helper.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+class ActivityLogAudienceHelper
+
+  def self.audience(activity_log_event)
+    domain = Rails.configuration.x.web_domain
+
+    if activity_log_event.type == 'outbound'
+      sender = activity_log_event.sender
+
+      if sender and match = sender.match(Regexp.new("https://#{domain}/users/([^/]*)"))
+        [match.captures[0]]
+      else
+        []
+      end
+    elsif activity_log_event.type == 'inbound'
+      if match = activity_log_event.path.match(Regexp.new("https://#{domain}/users/([^/]*)/inbox"))
+        [match.captures[0]]
+      elsif activity_log_event.path == "https://#{domain}/inbox"
+        ['to', 'bto', 'cc', 'bcc']
+          .map { |target| actors(activity_log_event.data[target]) }
+          .flatten
+          .uniq
+      else
+        []
+      end
+    else
+      []
+    end
+  end
+
+  private
+
+  def self.actors(string_or_array)
+    domain = Rails.configuration.x.web_domain
+
+    if string_or_array.nil?
+      []
+    elsif string_or_array.is_a?(String)
+      self.actors([string_or_array])
+    else
+      string_or_array.map do |string|
+        if match = string.match(Regexp.new("https://#{domain}/users/([^/]*)"))
+          match.captures[0]
+        elsif string.ends_with?("/followers")
+          Account
+            .joins(
+              "JOIN follows ON follows.account_id = accounts.id
+                JOIN accounts AS followed ON follows.target_account_id = followed.id
+                WHERE followed.followers_url = '#{string}'")
+            .map { |account| account.username }
+        else
+          nil
+        end
+      end.flatten.compact
+    end
+  end
+end

app/lib/activity_log_event.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class ActivityLogEvent
+  attr_accessor :type, :sender, :path, :data, :timestamp
+
+  def self.from_json_string(json_string)
+    json = Oj.load(json_string, mode: :strict)
+    ActivityLogEvent.new(json['type'], json['sender'], json['path'], json['data'])
+  end
+
+
+  def initialize(type, sender, path, data, timestamp = Time.now.utc.iso8601)
+    @type = type
+    @sender = sender
+    @path = path
+    @data = data
+    @timestamp = timestamp
+  end
+end

app/lib/activity_log_publisher.rb

@@ -0,0 +1,10 @@
+class ActivityLogPublisher
+
+  def initialize
+    @redis = RedisConfiguration.new.connection
+  end
+
+  def publish(log_event)
+    @redis.publish('activity_log', Oj.dump(log_event))
+  end
+end

app/lib/activity_logger.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class ActivityLogger
+
+  @@loggers = Hash.new { |hash, key| hash[key] = [] }
+
+  def self.register(id, sse)
+    @@loggers[id] << sse
+  end
+
+  def self.unregister(id, sse)
+    @@loggers[id].delete(sse)
+  end
+
+  def self.log(id, event)
+    @@loggers[id].each do |logger|
+      logger.write event
+    rescue
+      puts 'rescued'
+      logger.close
+      puts 'closed logger'
+    end
+  end
+
+  def self.reset
+    @@loggers.clear
+  end
+
+  Thread.new {
+    while true
+      event = ActivityLogEvent.new('keep-alive', nil, nil, nil)
+      @@loggers.each_key do |key|
+        ActivityLogger.log(key, event)
+      end
+
+      sleep 10
+    end
+  }
+end

app/models/account_migration.rb

@@ -34,14 +34,6 @@ class AccountMigration < ApplicationRecord
   attr_accessor :current_password, :current_username
 
   def save_with_challenge(current_user)
-    if current_user.encrypted_password.present?
-      errors.add(:current_password, :invalid) unless current_user.valid_password?(current_password)
-    else
-      errors.add(:current_username, :invalid) unless account.username == current_username
-    end
-
-    return false unless errors.empty?
-
     with_lock("account_migration:#{account.id}") do
       save
     end

app/models/form/redirect.rb

@@ -12,14 +12,6 @@ class Form::Redirect
   validate :validate_target_account
 
   def valid_with_challenge?(current_user)
-    if current_user.encrypted_password.present?
-      errors.add(:current_password, :invalid) unless current_user.valid_password?(current_password)
-    else
-      errors.add(:current_username, :invalid) unless account.username == current_username
-    end
-
-    return false unless errors.empty?
-
     set_target_account
     valid?
   end

app/validators/registration_form_time_validator.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class RegistrationFormTimeValidator < ActiveModel::Validator
-  REGISTRATION_FORM_MIN_TIME = 3.seconds.freeze
+  REGISTRATION_FORM_MIN_TIME = 0.5.seconds.freeze
 
   def validate(user)
     user.errors.add(:base, I18n.t('auth.too_fast')) if user.registration_form_time.present? && user.registration_form_time > REGISTRATION_FORM_MIN_TIME.ago

app/views/auth/registrations/edit.html.haml

@@ -3,31 +3,6 @@
 
 = render 'status'
 
-%h3= t('auth.security')
-
-= simple_form_for(resource, as: resource_name, url: registration_path(resource_name), html: { method: :put, class: 'auth_edit', novalidate: false }) do |f|
-  = render 'shared/error_messages', object: resource
-
-  - if !use_seamless_external_login? || resource.encrypted_password.present?
-    .fields-row
-      .fields-row__column.fields-group.fields-row__column-6
-        = f.input :email, wrapper: :with_label, input_html: { 'aria-label' => t('simple_form.labels.defaults.email') }, required: true, disabled: current_account.suspended?
-      .fields-row__column.fields-group.fields-row__column-6
-        = f.input :current_password, wrapper: :with_label, input_html: { 'aria-label' => t('simple_form.labels.defaults.current_password'), :autocomplete => 'current-password' }, required: true, disabled: current_account.suspended?, hint: false
-
-    .fields-row
-      .fields-row__column.fields-group.fields-row__column-6
-        = f.input :password, wrapper: :with_label, label: t('simple_form.labels.defaults.new_password'), input_html: { 'aria-label' => t('simple_form.labels.defaults.new_password'), :autocomplete => 'new-password', :minlength => User.password_length.first, :maxlength => User.password_length.last }, hint: t('simple_form.hints.defaults.password'), disabled: current_account.suspended?
-      .fields-row__column.fields-group.fields-row__column-6
-        = f.input :password_confirmation, wrapper: :with_label, label: t('simple_form.labels.defaults.confirm_new_password'), input_html: { 'aria-label' => t('simple_form.labels.defaults.confirm_new_password'), :autocomplete => 'new-password' }, disabled: current_account.suspended?
-
-    .actions
-      = f.button :button, t('generic.save_changes'), type: :submit, class: 'button', disabled: current_account.suspended?
-  - else
-    %p.hint= t('users.seamless_external_login')
-
-%hr.spacer/
-
 = render 'sessions'
 
 - unless current_account.suspended?

app/views/auth/registrations/new.html.haml

@@ -6,7 +6,7 @@
 
 = simple_form_for(resource, as: resource_name, url: registration_path(resource_name), html: { novalidate: false }) do |f|
   %h1.title= t('auth.sign_up.title', domain: site_hostname)
-  %p.lead= t('auth.sign_up.preamble')
+  %p.lead= t('auth.sign_up.activity_log_preamble_html')
 
   = render 'shared/error_messages', object: resource
 
@@ -16,12 +16,6 @@
       = render 'application/card', account: @invite.user.account
 
   .fields-group
-    = f.simple_fields_for :account do |ff|
-      = ff.input :display_name, wrapper: :with_label, label: false, required: false, input_html: { 'aria-label' => t('simple_form.labels.defaults.display_name'), :autocomplete => 'off', placeholder: t('simple_form.labels.defaults.display_name') }
-      = ff.input :username, wrapper: :with_label, label: false, required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.username'), :autocomplete => 'off', placeholder: t('simple_form.labels.defaults.username'), pattern: '[a-zA-Z0-9_]+', maxlength: 30 }, append: "@#{site_hostname}", hint: false
-    = f.input :email, placeholder: t('simple_form.labels.defaults.email'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.email'), :autocomplete => 'username' }, hint: false
-    = f.input :password, placeholder: t('simple_form.labels.defaults.password'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.password'), :autocomplete => 'new-password', :minlength => User.password_length.first, :maxlength => User.password_length.last }, hint: false
-    = f.input :password_confirmation, placeholder: t('simple_form.labels.defaults.confirm_password'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.confirm_password'), :autocomplete => 'new-password' }, hint: false
     = f.input :confirm_password, as: :string, placeholder: t('simple_form.labels.defaults.honeypot', label: t('simple_form.labels.defaults.password')), required: false, input_html: { 'aria-label' => t('simple_form.labels.defaults.honeypot', label: t('simple_form.labels.defaults.password')), :autocomplete => 'off' }, hint: false
     = f.input :website, as: :url, wrapper: :with_label, label: t('simple_form.labels.defaults.honeypot', label: 'Website'), required: false, input_html: { 'aria-label' => t('simple_form.labels.defaults.honeypot', label: 'Website'), :autocomplete => 'off' }
 
@@ -39,5 +33,3 @@
 
   .actions
     = f.button :button, @invite.present? ? t('auth.register') : sign_up_message, type: :submit
-
-.form-footer= render 'auth/shared/links'

app/views/settings/migration/redirects/new.html.haml

@@ -17,11 +17,5 @@
     .fields-row__column.fields-group.fields-row__column-6
       = f.input :acct, wrapper: :with_block_label, input_html: { autocapitalize: 'none', autocorrect: 'off' }, label: t('simple_form.labels.account_migration.acct'), hint: t('simple_form.hints.account_migration.acct')
 
-    .fields-row__column.fields-group.fields-row__column-6
-      - if current_user.encrypted_password.present?
-        = f.input :current_password, wrapper: :with_block_label, input_html: { :autocomplete => 'current-password' }, required: true
-      - else
-        = f.input :current_username, wrapper: :with_block_label, input_html: { :autocomplete => 'off' }, required: true
-
   .actions
     = f.button :button, t('migrations.set_redirect'), type: :submit, class: 'button button--destructive'

app/views/settings/migrations/show.html.haml

@@ -46,12 +46,6 @@
     .fields-row__column.fields-group.fields-row__column-6
       = f.input :acct, wrapper: :with_block_label, input_html: { autocapitalize: 'none', autocorrect: 'off' }, disabled: on_cooldown?
 
-    .fields-row__column.fields-group.fields-row__column-6
-      - if current_user.encrypted_password.present?
-        = f.input :current_password, wrapper: :with_block_label, input_html: { :autocomplete => 'current-password' }, required: true, disabled: on_cooldown?
-      - else
-        = f.input :current_username, wrapper: :with_block_label, input_html: { :autocomplete => 'off' }, required: true, disabled: on_cooldown?
-
   .actions
     = f.button :button, t('migrations.proceed_with_move'), type: :submit, class: 'button button--destructive', disabled: on_cooldown?
 

app/workers/activitypub/delivery_worker.rb

@@ -12,6 +12,10 @@ class ActivityPub::DeliveryWorker
 
   HEADERS = { 'Content-Type' => 'application/activity+json' }.freeze
 
+  def initialize
+    @activity_log_publisher = ActivityLogPublisher.new
+  end
+
   def perform(json, source_account_id, inbox_url, options = {})
     return unless DeliveryFailureTracker.available?(inbox_url)
 
@@ -22,6 +26,11 @@ class ActivityPub::DeliveryWorker
     @host           = Addressable::URI.parse(inbox_url).normalized_site
     @performed      = false
 
+    event = ActivityLogEvent.new('outbound', "https://#{Rails.configuration.x.web_domain}/users/#{@source_account.username}", inbox_url, Oj.load(json, mode: :strict))
+
+    @activity_log_publisher.publish(event)
+
+
     perform_request
   ensure
     if @inbox_url.present?

app/workers/scheduler/old_account_cleanup_scheduler.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+class Scheduler::OldAccountCleanupScheduler
+  include Sidekiq::Worker
+
+  # Each processed deletion request may enqueue an enormous
+  # amount of jobs in the `pull` queue, so only enqueue when
+  # the queue is empty or close to being so.
+  MAX_PULL_SIZE = 50
+
+  # Since account deletion is very expensive, we want to avoid
+  # overloading the server by queing too much at once.
+  MAX_DELETIONS_PER_JOB = 5
+
+  sidekiq_options retry: 0
+
+  def perform
+    return if Sidekiq::Queue.new('pull').size > MAX_PULL_SIZE
+
+    clean_old_accounts!
+  end
+
+  private
+
+  def clean_old_accounts!
+    Account
+      # only fetch local accounts
+      .where("domain IS NULL")
+      # id -99 is the instance actor
+      .where("id <> -99")
+      # don't delete admin
+      .where("username <> 'admin'")
+      .where("created_at < ?", 1.day.ago)
+      .order(created_at: :asc)
+      .limit(MAX_DELETIONS_PER_JOB)
+      .each do |account|
+        AccountDeletionWorker.perform_async(account.id, { :reserve_username => false })
+      end
+  end
+end

config/environments/development.rb

@@ -74,7 +74,8 @@ Rails.application.configure do
   # If using a Heroku, Vagrant or generic remote development environment,
   # use letter_opener_web, accessible at  /letter_opener.
   # Otherwise, use letter_opener, which launches a browser window to view sent mail.
-  config.action_mailer.delivery_method = (ENV['HEROKU'] || ENV['VAGRANT'] || ENV['REMOTE_DEV']) ? :letter_opener_web : :letter_opener
+  # config.action_mailer.delivery_method = (ENV['HEROKU'] || ENV['VAGRANT'] || ENV['REMOTE_DEV']) ? :letter_opener_web : :letter_opener
+  config.action_mailer.delivery_method = :file
 
   config.after_initialize do
     Bullet.enable        = true

config/environments/production.rb

@@ -130,7 +130,7 @@ Rails.application.configure do
     :ssl                  => ENV['SMTP_SSL'].presence && ENV['SMTP_SSL'] == 'true',
   }
 
-  config.action_mailer.delivery_method = ENV.fetch('SMTP_DELIVERY_METHOD', 'smtp').to_sym
+  config.action_mailer.delivery_method = :file
 
   config.action_dispatch.default_headers = {
     'Server'                 => 'Mastodon',

config/locales/devise.en.yml

@@ -2,7 +2,7 @@
 en:
   devise:
     confirmations:
-      confirmed: Your email address has been successfully confirmed.
+      confirmed: Your account is fully functional.
       send_instructions: You will receive an email with instructions for how to confirm your email address in a few minutes. Please check your spam folder if you didn't receive this email.
       send_paranoid_instructions: If your email address exists in our database, you will receive an email with instructions for how to confirm your email address in a few minutes. Please check your spam folder if you didn't receive this email.
     failure:

config/locales/en.yml

@@ -953,6 +953,7 @@ en:
       title: Setup
     sign_up:
       preamble: With an account on this Mastodon server, you'll be able to follow any other person on the network, regardless of where their account is hosted.
+      activity_log_preamble_html: ActivityPub.Academy is a learning resource for <a href="https://www.w3.org/TR/activitypub/">ActivityPub</a>. The protocol is brought to life by showing Activities between different instances in real time! <br/><br/> After signing up, you are given a fully functional Mastodon account. You can follow other accounts, create posts, repost, like, etc. These actions generate Activities following the ActivityPub spec, which will be shown to you in real time. You can learn more about this on my <a href="//seb.jambor.dev">blog</a>. <br/><br/> Note that your account is only valid for 24 hours and will be deleted automatically afterwards.
       title: Let's get you set up on %{domain}.
     status:
       account_status: Account status

config/puma.rb

@@ -1,3 +1,5 @@
+require_relative '../lib/activity_log_subscriber'
+
 persistent_timeout ENV.fetch('PERSISTENT_TIMEOUT') { 20 }.to_i
 
 threads_count = ENV.fetch('MAX_THREADS') { 5 }.to_i
@@ -18,6 +20,10 @@ on_worker_boot do
   ActiveSupport.on_load(:active_record) do
     ActiveRecord::Base.establish_connection
   end
+
+  Thread.new {
+    ActivityLogSubscriber.new.start
+  }
 end
 
 plugin :tmp_restart

config/routes.rb

@@ -24,6 +24,8 @@ Rails.application.routes.draw do
     /search
     /publish
     /follow_requests
+    /activity_log
+    /activitypub_explorer
     /blocks
     /domain_blocks
     /mutes
@@ -513,6 +515,10 @@ Rails.application.routes.draw do
         resources :confirmations, only: [:create]
       end
 
+      resource :activity_log, only: [:show], controller: 'activity_log'
+
+      get '/json_ld', to: 'json_ld#show'
+
       resource :instance, only: [:show] do
         resources :peers, only: [:index], controller: 'instances/peers'
         resources :rules, only: [:index], controller: 'instances/rules'

config/sidekiq.yml

@@ -58,3 +58,7 @@
     interval: 1 minute
     class: Scheduler::SuspendedUserCleanupScheduler
     queue: scheduler
+  old_account_cleanup_scheduler:
+    interval: 1 minute
+    class: Scheduler::OldAccountCleanupScheduler
+    queue: scheduler

lib/activity_log_subscriber.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+require 'redis'
+
+class ActivityLogSubscriber
+  def start
+    redis = RedisConfiguration.new.connection
+
+    redis.subscribe('activity_log') do |on|
+      on.message do |channel, message|
+        event = ActivityLogEvent.from_json_string(message)
+
+        ActivityLogAudienceHelper.audience(event)
+          .each { |username| ActivityLogger.log(username, event) }
+      end
+    end
+  end
+end

package.json

@@ -35,6 +35,7 @@
     "@github/webauthn-json": "^0.5.7",
     "@rails/ujs": "^6.1.7",
     "abortcontroller-polyfill": "^1.7.5",
+    "activitypub-visualization": "^1.1.0",
     "array-includes": "^3.1.5",
     "arrow-key-navigation": "^1.2.0",
     "autoprefixer": "^9.8.8",

spec/fixtures/activity_log_events/inbound-to-users-inbox.json

@@ -0,0 +1,13 @@
+{
+  "timestamp":"2022-12-08T17:12:38Z",
+  "sender": "https://other.org/users/alice",
+  "type": "inbound",
+  "path": "https://example.com/users/bob/inbox",
+  "data": {
+    "@context": "https://www.w3.org/ns/activitystreams",
+    "id": "https://other.org/a5f25e0a-98d6-4e5c-baad-65318cd4d67d",
+    "type": "Follow",
+    "actor": "https://other.org/users/alice",
+    "object": "https://example.com/users/bob"
+  }
+}

spec/fixtures/activity_log_events/inbound-with-duplicate-recipients.json

@@ -0,0 +1,44 @@
+{
+  "timestamp":"2022-12-08T17:12:38Z",
+  "sender": "https://other.org/users/bob/",
+  "type": "inbound",
+  "path": "https://example.com/inbox",
+  "data": {
+    "@context": "https://www.w3.org/ns/activitystreams",
+    "actor": "https://other.org/users/bob/",
+    "id": "https://other.org/users/bob/statuses/109473290785654613/activity",
+    "object": {
+      "attributedTo": "https://other.org/users/bob/",
+      "content": "A post to selected audiences",
+      "id": "https://other.org/users/bob/statuses/109473290785654613",
+      "to": [
+        "https://www.w3.org/ns/activitystreams#Public",
+        "https://example.com/users/first-to",
+        "https://example.com/users/first-to",
+        "https://example.com/users/second-to"
+      ],
+      "bto": "https://example.com/users/first-to",
+      "cc": [
+        "https://example.com/users/second-to"
+      ],
+      "bcc": [
+        "https://example.com/users/first-to"
+      ],
+      "type": "Note"
+    },
+    "to": [
+      "https://www.w3.org/ns/activitystreams#Public",
+      "https://example.com/users/first-to",
+      "https://example.com/users/first-to",
+      "https://example.com/users/second-to"
+    ],
+    "bto": "https://example.com/users/first-to",
+    "cc": [
+      "https://example.com/users/second-to"
+    ],
+    "bcc": [
+      "https://example.com/users/first-to"
+    ],
+    "type": "Create"
+  }
+}

spec/fixtures/activity_log_events/inbound-with-follower-recipients.json

@@ -0,0 +1,26 @@
+{
+  "timestamp":"2022-12-08T17:12:38Z",
+  "sender": "https://other.org/users/bob/",
+  "type": "inbound",
+  "path": "https://example.com/inbox",
+  "data": {
+    "@context": "https://www.w3.org/ns/activitystreams",
+    "actor": "https://other.org/users/bob/",
+    "id": "https://other.org/users/bob/statuses/109473290785654613/activity",
+    "object": {
+      "attributedTo": "https://other.org/users/bob/",
+      "content": "A post to selected audiences",
+      "id": "https://other.org/users/bob/statuses/109473290785654613",
+      "to": [
+        "https://www.w3.org/ns/activitystreams#Public",
+        "https://other.org/users/bob/followers"
+      ],
+      "type": "Note"
+    },
+    "to": [
+      "https://www.w3.org/ns/activitystreams#Public",
+      "https://other.org/users/bob/followers"
+    ],
+    "type": "Create"
+  }
+}

spec/fixtures/activity_log_events/inbound-with-multiple-recipients.json

@@ -0,0 +1,44 @@
+{
+  "timestamp":"2022-12-08T17:12:38Z",
+  "sender": "https://other.org/users/bob/",
+  "type": "inbound",
+  "path": "https://example.com/inbox",
+  "data": {
+    "@context": "https://www.w3.org/ns/activitystreams",
+    "actor": "https://other.org/users/bob/",
+    "id": "https://other.org/users/bob/statuses/109473290785654613/activity",
+    "object": {
+      "attributedTo": "https://other.org/users/bob/",
+      "content": "A post to selected audiences",
+      "id": "https://other.org/users/bob/statuses/109473290785654613",
+      "to": [
+        "https://www.w3.org/ns/activitystreams#Public",
+        "https://example.com/users/first-to",
+        "https://example.com/users/second-to",
+        "https://other.org/users/other-instance"
+      ],
+      "bto": "https://example.com/users/single-bto",
+      "cc": [
+        "https://example.com/users/one-cc"
+      ],
+      "bcc": [
+        "https://example.com/users/one-bcc"
+      ],
+      "type": "Note"
+    },
+    "to": [
+      "https://www.w3.org/ns/activitystreams#Public",
+      "https://example.com/users/first-to",
+      "https://example.com/users/second-to",
+      "https://other.org/users/other-instance"
+    ],
+    "bto": "https://example.com/users/single-bto",
+    "cc": [
+      "https://example.com/users/one-cc"
+    ],
+    "bcc": [
+      "https://example.com/users/one-bcc"
+    ],
+    "type": "Create"
+  }
+}

spec/fixtures/activity_log_events/outbound.json

@@ -0,0 +1,13 @@
+{
+  "timestamp":"2022-12-08T17:12:38Z",
+  "sender": "https://example.com/users/alice",
+  "type": "outbound",
+  "path": "https://other.org/users/bob/inbox",
+  "data": {
+    "@context": "https://www.w3.org/ns/activitystreams",
+    "id": "https://example.com/a5f25e0a-98d6-4e5c-baad-65318cd4d67d",
+    "type": "Follow",
+    "actor": "https://example.com/users/alice",
+    "object": "https://other.org/users/bob"
+  }
+}

spec/lib/activity_log_audience_helper_spec.rb

@@ -0,0 +1,89 @@
+require 'json'
+require 'rails_helper'
+
+def activity_log_event_fixture(name)
+  json_string = File.read(Rails.root.join('spec', 'fixtures', 'activity_log_events', name))
+
+  ActivityLogEvent.from_json_string(json_string)
+end
+
+RSpec.describe ActivityLogAudienceHelper do
+  describe '#audience' do
+    around do |example|
+      before = Rails.configuration.x.web_domain
+      example.run
+      Rails.configuration.x.web_domain = before
+    end
+
+    describe 'for inbound events' do
+      it 'returns the author if the domain matches' do
+        Rails.configuration.x.web_domain = 'example.com'
+        outbound_event = activity_log_event_fixture('outbound.json')
+
+        expect(ActivityLogAudienceHelper.audience(outbound_event)).to eq ['alice']
+      end
+
+      it 'returns nothing if the domain does not match' do
+        Rails.configuration.x.web_domain = 'does-not-match.com'
+        outbound_event = activity_log_event_fixture('outbound.json')
+
+        expect(ActivityLogAudienceHelper.audience(outbound_event)).to eq []
+      end
+
+      it 'returns nothing if the activity does not have an actor' do
+        Rails.configuration.x.web_domain = 'example.com'
+        outbound_event = activity_log_event_fixture('outbound.json')
+        outbound_event.data.delete('actor')
+
+        expect(ActivityLogAudienceHelper.audience(outbound_event)).to eq []
+      end
+    end
+
+    describe 'for outbound events' do
+      it 'returns the inbox owner if it is sent to a personal inbox' do
+        Rails.configuration.x.web_domain = 'example.com'
+        inbound_event = activity_log_event_fixture('inbound-to-users-inbox.json')
+
+        expect(ActivityLogAudienceHelper.audience(inbound_event)).to eq ['bob']
+      end
+
+      it 'returns direct audience from to, bto, cc, bcc if sent to public inbox' do
+        Rails.configuration.x.web_domain = 'example.com'
+        inbound_event = activity_log_event_fixture('inbound-with-multiple-recipients.json')
+
+        expect(ActivityLogAudienceHelper.audience(inbound_event)).to match_array([
+          'first-to',
+          'second-to',
+          'single-bto',
+          'one-cc',
+          'one-bcc'
+        ])
+      end
+
+      it 'returns followers from to, bto, cc, bcc if sent to public inbox' do
+        Rails.configuration.x.web_domain = 'example.com'
+        inbound_event = activity_log_event_fixture('inbound-with-follower-recipients.json')
+
+        bob = Fabricate(:account, username: 'bob', followers_url: 'https://other.org/users/bob/followers')
+        Fabricate(:account, username: 'first_follower').follow!(bob)
+        Fabricate(:account, username: 'second_follower').follow!(bob)
+
+        expect(ActivityLogAudienceHelper.audience(inbound_event)).to match_array([
+          'first_follower',
+          'second_follower',
+        ])
+      end
+
+      it 'removes duplicates from audience' do
+        Rails.configuration.x.web_domain = 'example.com'
+        inbound_event = activity_log_event_fixture('inbound-with-duplicate-recipients.json')
+
+        expect(ActivityLogAudienceHelper.audience(inbound_event)).to match_array([
+          'first-to',
+          'second-to'
+        ])
+      end
+
+    end
+  end
+end

spec/lib/activity_logger_spec.rb

@@ -0,0 +1,67 @@
+require 'json'
+require 'rails_helper'
+
+RSpec.describe ActivityLogger do
+
+  after(:each) do
+    ActivityLogger.reset
+  end
+
+  describe 'log' do
+
+    it 'sends events to all listeners of the same id' do
+      sse1 = spy('sse1')
+      sse2 = spy('sse2')
+      event = double('event')
+
+      ActivityLogger.register('test_id', sse1)
+      ActivityLogger.register('test_id', sse2)
+
+      ActivityLogger.log('test_id', event)
+
+      expect(sse1).to have_received(:write).with(event)
+      expect(sse2).to have_received(:write).with(event)
+    end
+
+    it 'sends events to all listeners even if some fail' do
+      sse1 = spy('sse1')
+      sse2 = spy('sse2')
+      event = double('event')
+
+      allow(sse1).to receive(:write).and_throw(:error)
+
+      ActivityLogger.register('test_id', sse1)
+      ActivityLogger.register('test_id', sse2)
+
+      ActivityLogger.log('test_id', event)
+
+      expect(sse2).to have_received(:write).with(event)
+    end
+
+    it 'does not send events to listeners of a different id' do
+      sse = spy('sse')
+      event = double('event')
+
+      ActivityLogger.register('test_id', sse)
+
+      ActivityLogger.log('other_id', event)
+
+      expect(sse).to_not have_received(:write).with(event)
+    end
+
+    it 'does not send events to listeners after unregistering' do
+      sse1 = spy('sse1')
+      sse2 = spy('sse2')
+      event = double('event')
+
+      ActivityLogger.register('test_id', sse1)
+      ActivityLogger.register('test_id', sse2)
+      ActivityLogger.unregister('test_id', sse1)
+
+      ActivityLogger.log('test_id', event)
+
+      expect(sse1).to_not have_received(:write).with(event)
+      expect(sse2).to have_received(:write).with(event)
+    end
+  end
+end

yarn.lock

@@ -2322,6 +2322,11 @@ acorn@^8.0.4, acorn@^8.1.0, acorn@^8.5.0, acorn@^8.8.0:
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.8.0.tgz#88c0187620435c7f6015803f5539dae05a9dbea8"
   integrity sha512-QOxyigPVrpZ2GXT+PFyZTl6TtOFc5egxHIP9IlQ+RbupQuX4RkT/Bee4/kQuC02Xkzg84JcT7oLYtDIQxp+v7w==
 
+activitypub-visualization@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/activitypub-visualization/-/activitypub-visualization-1.1.0.tgz#db7875657aa3215f6d7be16795964c82c1021efe"
+  integrity sha512-0DrnCdmpx5551q0vZiQYHu3ZsVVFP0JJKLHQpbLmgetVJxGjRoZC7iwjh+tvyYixBhUneIAhVJ2VH0bugiAwFA==
+
 agent-base@6:
   version "6.0.2"
   resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-6.0.2.tgz#49fff58577cfee3f37176feab4c22e00f86d7f77"