From 44b2ee3485ba0845e5910cefcb4b1e2f84f34470 Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Tue, 5 Jul 2022 02:41:40 +0200
Subject: Add customizable user roles (#18641)

* Add customizable user roles

* Various fixes and improvements

* Add migration for old settings and fix tootctl role management
---
 .../api/v1/admin/account_actions_controller.rb       |  7 ++++++-
 app/controllers/api/v1/admin/accounts_controller.rb  |  6 ++++--
 .../api/v1/admin/dimensions_controller.rb            |  6 +++++-
 .../api/v1/admin/domain_allows_controller.rb         |  2 +-
 .../api/v1/admin/domain_blocks_controller.rb         |  2 +-
 app/controllers/api/v1/admin/measures_controller.rb  |  6 +++++-
 app/controllers/api/v1/admin/reports_controller.rb   |  2 +-
 app/controllers/api/v1/admin/retention_controller.rb |  6 +++++-
 .../api/v1/admin/trends/links_controller.rb          | 20 +++++++++++---------
 .../api/v1/admin/trends/statuses_controller.rb       | 20 +++++++++++---------
 .../api/v1/admin/trends/tags_controller.rb           | 20 +++++++++++---------
 app/controllers/api/v1/trends/links_controller.rb    | 10 +++++++---
 app/controllers/api/v1/trends/statuses_controller.rb | 10 +++++++---
 app/controllers/api/v1/trends/tags_controller.rb     | 12 ++++++++++--
 14 files changed, 85 insertions(+), 44 deletions(-)

(limited to 'app/controllers/api/v1')

diff --git a/app/controllers/api/v1/admin/account_actions_controller.rb b/app/controllers/api/v1/admin/account_actions_controller.rb
index 6c9e04402..7249797a4 100644
--- a/app/controllers/api/v1/admin/account_actions_controller.rb
+++ b/app/controllers/api/v1/admin/account_actions_controller.rb
@@ -1,11 +1,16 @@
 # frozen_string_literal: true
 
 class Api::V1::Admin::AccountActionsController < Api::BaseController
+  include Authorization
+
   before_action -> { authorize_if_got_token! :'admin:write', :'admin:write:accounts' }
-  before_action :require_staff!
   before_action :set_account
 
+  after_action :verify_authorized
+
   def create
+    authorize @account, :show?
+
     account_action                 = Admin::AccountAction.new(resource_params)
     account_action.target_account  = @account
     account_action.current_account = current_account
diff --git a/app/controllers/api/v1/admin/accounts_controller.rb b/app/controllers/api/v1/admin/accounts_controller.rb
index 65ed69f7b..0dee02e94 100644
--- a/app/controllers/api/v1/admin/accounts_controller.rb
+++ b/app/controllers/api/v1/admin/accounts_controller.rb
@@ -8,11 +8,11 @@ class Api::V1::Admin::AccountsController < Api::BaseController
 
   before_action -> { authorize_if_got_token! :'admin:read', :'admin:read:accounts' }, only: [:index, :show]
   before_action -> { authorize_if_got_token! :'admin:write', :'admin:write:accounts' }, except: [:index, :show]
-  before_action :require_staff!
   before_action :set_accounts, only: :index
   before_action :set_account, except: :index
   before_action :require_local_account!, only: [:enable, :approve, :reject]
 
+  after_action :verify_authorized
   after_action :insert_pagination_headers, only: :index
 
   FILTER_PARAMS = %i(
@@ -119,7 +119,9 @@ class Api::V1::Admin::AccountsController < Api::BaseController
       translated_params[:status] = status.to_s if params[status].present?
     end
 
-    translated_params[:permissions] = 'staff' if params[:staff].present?
+    if params[:staff].present?
+      translated_params[:role_ids] = UserRole.that_can(:manage_reports).map(&:id)
+    end
 
     translated_params
   end
diff --git a/app/controllers/api/v1/admin/dimensions_controller.rb b/app/controllers/api/v1/admin/dimensions_controller.rb
index 49a5be1c3..4a72ad08b 100644
--- a/app/controllers/api/v1/admin/dimensions_controller.rb
+++ b/app/controllers/api/v1/admin/dimensions_controller.rb
@@ -1,11 +1,15 @@
 # frozen_string_literal: true
 
 class Api::V1::Admin::DimensionsController < Api::BaseController
+  include Authorization
+
   before_action -> { authorize_if_got_token! :'admin:read' }
-  before_action :require_staff!
   before_action :set_dimensions
 
+  after_action :verify_authorized
+
   def create
+    authorize :dashboard, :index?
     render json: @dimensions, each_serializer: REST::Admin::DimensionSerializer
   end
 
diff --git a/app/controllers/api/v1/admin/domain_allows_controller.rb b/app/controllers/api/v1/admin/domain_allows_controller.rb
index 838978ddb..59aa807d6 100644
--- a/app/controllers/api/v1/admin/domain_allows_controller.rb
+++ b/app/controllers/api/v1/admin/domain_allows_controller.rb
@@ -8,10 +8,10 @@ class Api::V1::Admin::DomainAllowsController < Api::BaseController
 
   before_action -> { authorize_if_got_token! :'admin:read', :'admin:read:domain_allows' }, only: [:index, :show]
   before_action -> { authorize_if_got_token! :'admin:write', :'admin:write:domain_allows' }, except: [:index, :show]
-  before_action :require_staff!
   before_action :set_domain_allows, only: :index
   before_action :set_domain_allow, only: [:show, :destroy]
 
+  after_action :verify_authorized
   after_action :insert_pagination_headers, only: :index
 
   PAGINATION_PARAMS = %i(limit).freeze
diff --git a/app/controllers/api/v1/admin/domain_blocks_controller.rb b/app/controllers/api/v1/admin/domain_blocks_controller.rb
index 229870eee..de8fd9d08 100644
--- a/app/controllers/api/v1/admin/domain_blocks_controller.rb
+++ b/app/controllers/api/v1/admin/domain_blocks_controller.rb
@@ -8,10 +8,10 @@ class Api::V1::Admin::DomainBlocksController < Api::BaseController
 
   before_action -> { authorize_if_got_token! :'admin:read', :'admin:read:domain_blocks' }, only: [:index, :show]
   before_action -> { authorize_if_got_token! :'admin:write', :'admin:write:domain_blocks' }, except: [:index, :show]
-  before_action :require_staff!
   before_action :set_domain_blocks, only: :index
   before_action :set_domain_block, only: [:show, :update, :destroy]
 
+  after_action :verify_authorized
   after_action :insert_pagination_headers, only: :index
 
   PAGINATION_PARAMS = %i(limit).freeze
diff --git a/app/controllers/api/v1/admin/measures_controller.rb b/app/controllers/api/v1/admin/measures_controller.rb
index da95d3422..d78d7e10b 100644
--- a/app/controllers/api/v1/admin/measures_controller.rb
+++ b/app/controllers/api/v1/admin/measures_controller.rb
@@ -1,11 +1,15 @@
 # frozen_string_literal: true
 
 class Api::V1::Admin::MeasuresController < Api::BaseController
+  include Authorization
+
   before_action -> { authorize_if_got_token! :'admin:read' }
-  before_action :require_staff!
   before_action :set_measures
 
+  after_action :verify_authorized
+
   def create
+    authorize :dashboard, :index?
     render json: @measures, each_serializer: REST::Admin::MeasureSerializer
   end
 
diff --git a/app/controllers/api/v1/admin/reports_controller.rb b/app/controllers/api/v1/admin/reports_controller.rb
index 865ba3d23..9dfb181a2 100644
--- a/app/controllers/api/v1/admin/reports_controller.rb
+++ b/app/controllers/api/v1/admin/reports_controller.rb
@@ -8,10 +8,10 @@ class Api::V1::Admin::ReportsController < Api::BaseController
 
   before_action -> { authorize_if_got_token! :'admin:read', :'admin:read:reports' }, only: [:index, :show]
   before_action -> { authorize_if_got_token! :'admin:write', :'admin:write:reports' }, except: [:index, :show]
-  before_action :require_staff!
   before_action :set_reports, only: :index
   before_action :set_report, except: :index
 
+  after_action :verify_authorized
   after_action :insert_pagination_headers, only: :index
 
   FILTER_PARAMS = %i(
diff --git a/app/controllers/api/v1/admin/retention_controller.rb b/app/controllers/api/v1/admin/retention_controller.rb
index 98d1a3d81..59d6b8388 100644
--- a/app/controllers/api/v1/admin/retention_controller.rb
+++ b/app/controllers/api/v1/admin/retention_controller.rb
@@ -1,11 +1,15 @@
 # frozen_string_literal: true
 
 class Api::V1::Admin::RetentionController < Api::BaseController
+  include Authorization
+
   before_action -> { authorize_if_got_token! :'admin:read' }
-  before_action :require_staff!
   before_action :set_cohorts
 
+  after_action :verify_authorized
+
   def create
+    authorize :dashboard, :index?
     render json: @cohorts, each_serializer: REST::Admin::CohortSerializer
   end
 
diff --git a/app/controllers/api/v1/admin/trends/links_controller.rb b/app/controllers/api/v1/admin/trends/links_controller.rb
index 0a191fe4b..cc6388980 100644
--- a/app/controllers/api/v1/admin/trends/links_controller.rb
+++ b/app/controllers/api/v1/admin/trends/links_controller.rb
@@ -1,17 +1,19 @@
 # frozen_string_literal: true
 
-class Api::V1::Admin::Trends::LinksController < Api::BaseController
+class Api::V1::Admin::Trends::LinksController < Api::V1::Trends::LinksController
   before_action -> { authorize_if_got_token! :'admin:read' }
-  before_action :require_staff!
-  before_action :set_links
-
-  def index
-    render json: @links, each_serializer: REST::Trends::LinkSerializer
-  end
 
   private
 
-  def set_links
-    @links = Trends.links.query.limit(limit_param(10))
+  def enabled?
+    super || current_user&.can?(:manage_taxonomies)
+  end
+
+  def links_from_trends
+    if current_user&.can?(:manage_taxonomies)
+      Trends.links.query
+    else
+      super
+    end
   end
 end
diff --git a/app/controllers/api/v1/admin/trends/statuses_controller.rb b/app/controllers/api/v1/admin/trends/statuses_controller.rb
index cb145f165..c39f77363 100644
--- a/app/controllers/api/v1/admin/trends/statuses_controller.rb
+++ b/app/controllers/api/v1/admin/trends/statuses_controller.rb
@@ -1,17 +1,19 @@
 # frozen_string_literal: true
 
-class Api::V1::Admin::Trends::StatusesController < Api::BaseController
+class Api::V1::Admin::Trends::StatusesController < Api::V1::Trends::StatusesController
   before_action -> { authorize_if_got_token! :'admin:read' }
-  before_action :require_staff!
-  before_action :set_statuses
-
-  def index
-    render json: @statuses, each_serializer: REST::StatusSerializer
-  end
 
   private
 
-  def set_statuses
-    @statuses = cache_collection(Trends.statuses.query.limit(limit_param(DEFAULT_STATUSES_LIMIT)), Status)
+  def enabled?
+    super || current_user&.can?(:manage_taxonomies)
+  end
+
+  def statuses_from_trends
+    if current_user&.can?(:manage_taxonomies)
+      Trends.statuses.query
+    else
+      super
+    end
   end
 end
diff --git a/app/controllers/api/v1/admin/trends/tags_controller.rb b/app/controllers/api/v1/admin/trends/tags_controller.rb
index 9c28b0412..f3c0c4b6b 100644
--- a/app/controllers/api/v1/admin/trends/tags_controller.rb
+++ b/app/controllers/api/v1/admin/trends/tags_controller.rb
@@ -1,17 +1,19 @@
 # frozen_string_literal: true
 
-class Api::V1::Admin::Trends::TagsController < Api::BaseController
+class Api::V1::Admin::Trends::TagsController < Api::V1::Trends::TagsController
   before_action -> { authorize_if_got_token! :'admin:read' }
-  before_action :require_staff!
-  before_action :set_tags
-
-  def index
-    render json: @tags, each_serializer: REST::Admin::TagSerializer
-  end
 
   private
 
-  def set_tags
-    @tags = Trends.tags.query.limit(limit_param(10))
+  def enabled?
+    super || current_user&.can?(:manage_taxonomies)
+  end
+
+  def tags_from_trends
+    if current_user&.can?(:manage_taxonomies)
+      Trends.tags.query
+    else
+      super
+    end
   end
 end
diff --git a/app/controllers/api/v1/trends/links_controller.rb b/app/controllers/api/v1/trends/links_controller.rb
index 2385fe438..1a9f918f2 100644
--- a/app/controllers/api/v1/trends/links_controller.rb
+++ b/app/controllers/api/v1/trends/links_controller.rb
@@ -13,10 +13,14 @@ class Api::V1::Trends::LinksController < Api::BaseController
 
   private
 
+  def enabled?
+    Setting.trends
+  end
+
   def set_links
     @links = begin
-      if Setting.trends
-        links_from_trends
+      if enabled?
+        links_from_trends.offset(offset_param).limit(limit_param(DEFAULT_LINKS_LIMIT))
       else
         []
       end
@@ -24,7 +28,7 @@ class Api::V1::Trends::LinksController < Api::BaseController
   end
 
   def links_from_trends
-    Trends.links.query.allowed.in_locale(content_locale).offset(offset_param).limit(limit_param(DEFAULT_LINKS_LIMIT))
+    Trends.links.query.allowed.in_locale(content_locale)
   end
 
   def insert_pagination_headers
diff --git a/app/controllers/api/v1/trends/statuses_controller.rb b/app/controllers/api/v1/trends/statuses_controller.rb
index 1f2fff582..c275d5fc8 100644
--- a/app/controllers/api/v1/trends/statuses_controller.rb
+++ b/app/controllers/api/v1/trends/statuses_controller.rb
@@ -11,10 +11,14 @@ class Api::V1::Trends::StatusesController < Api::BaseController
 
   private
 
+  def enabled?
+    Setting.trends
+  end
+
   def set_statuses
     @statuses = begin
-      if Setting.trends
-        cache_collection(statuses_from_trends, Status)
+      if enabled?
+        cache_collection(statuses_from_trends.offset(offset_param).limit(limit_param(DEFAULT_STATUSES_LIMIT)), Status)
       else
         []
       end
@@ -24,7 +28,7 @@ class Api::V1::Trends::StatusesController < Api::BaseController
   def statuses_from_trends
     scope = Trends.statuses.query.allowed.in_locale(content_locale)
     scope = scope.filtered_for(current_account) if user_signed_in?
-    scope.offset(offset_param).limit(limit_param(DEFAULT_STATUSES_LIMIT))
+    scope
   end
 
   def insert_pagination_headers
diff --git a/app/controllers/api/v1/trends/tags_controller.rb b/app/controllers/api/v1/trends/tags_controller.rb
index 38003f599..41f9ffac1 100644
--- a/app/controllers/api/v1/trends/tags_controller.rb
+++ b/app/controllers/api/v1/trends/tags_controller.rb
@@ -13,16 +13,24 @@ class Api::V1::Trends::TagsController < Api::BaseController
 
   private
 
+  def enabled?
+    Setting.trends
+  end
+
   def set_tags
     @tags = begin
-      if Setting.trends
-        Trends.tags.query.allowed.offset(offset_param).limit(limit_param(DEFAULT_TAGS_LIMIT))
+      if enabled?
+        tags_from_trends.offset(offset_param).limit(limit_param(DEFAULT_TAGS_LIMIT))
       else
         []
       end
     end
   end
 
+  def tags_from_trends
+    Trends.tags.query.allowed
+  end
+
   def insert_pagination_headers
     set_pagination_headers(next_path, prev_path)
   end
-- 
cgit 


From e7aa2be828f6a632dadd5c41e2364cea91ddbb2c Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Wed, 13 Jul 2022 15:03:28 +0200
Subject: Change how hashtags are normalized (#18795)

* Change how hashtags are normalized

* Fix tests
---
 app/controllers/admin/tags_controller.rb           |  4 ++-
 app/controllers/api/v1/featured_tags_controller.rb |  4 +--
 .../settings/featured_tags_controller.rb           |  1 -
 app/javascript/mastodon/actions/compose.js         | 15 +++++++++-
 app/lib/ascii_folding.rb                           | 10 +++++++
 app/lib/hashtag_normalizer.rb                      | 25 +++++++++++++++++
 app/models/account.rb                              |  2 +-
 app/models/custom_filter.rb                        |  6 ++--
 app/models/custom_filter_keyword.rb                |  4 +--
 app/models/featured_tag.rb                         | 31 ++++++++++++++-------
 app/models/tag.rb                                  | 20 +++++++++++---
 app/serializers/activitypub/hashtag_serializer.rb  |  4 +--
 app/serializers/rest/featured_tag_serializer.rb    |  4 +++
 app/serializers/rest/tag_serializer.rb             |  4 +++
 app/views/accounts/show.html.haml                  |  2 +-
 app/views/accounts/show.rss.ruby                   |  2 +-
 app/views/admin/tags/show.html.haml                |  4 +--
 app/views/admin/trends/tags/_tag.html.haml         |  2 +-
 app/views/admin_mailer/_new_trending_tags.text.erb |  4 +--
 app/views/settings/featured_tags/index.html.haml   |  2 +-
 app/views/tags/_og.html.haml                       |  4 +--
 app/views/tags/show.html.haml                      |  6 ++--
 app/views/tags/show.rss.ruby                       |  6 ++--
 config/initializers/inflections.rb                 |  1 +
 .../20220710102457_add_display_name_to_tags.rb     |  5 ++++
 db/schema.rb                                       |  3 +-
 spec/lib/hashtag_normalizer_spec.rb                | 29 ++++++++++++++++++++
 spec/models/tag_spec.rb                            |  8 +++---
 streaming/index.js                                 | 32 ++++++++++++++++++++--
 29 files changed, 193 insertions(+), 51 deletions(-)
 create mode 100644 app/lib/ascii_folding.rb
 create mode 100644 app/lib/hashtag_normalizer.rb
 create mode 100644 db/migrate/20220710102457_add_display_name_to_tags.rb
 create mode 100644 spec/lib/hashtag_normalizer_spec.rb

(limited to 'app/controllers/api/v1')

diff --git a/app/controllers/admin/tags_controller.rb b/app/controllers/admin/tags_controller.rb
index 749e2f144..4f727c398 100644
--- a/app/controllers/admin/tags_controller.rb
+++ b/app/controllers/admin/tags_controller.rb
@@ -16,6 +16,8 @@ module Admin
       if @tag.update(tag_params.merge(reviewed_at: Time.now.utc))
         redirect_to admin_tag_path(@tag.id), notice: I18n.t('admin.tags.updated_msg')
       else
+        @time_period = (6.days.ago.to_date...Time.now.utc.to_date)
+
         render :show
       end
     end
@@ -27,7 +29,7 @@ module Admin
     end
 
     def tag_params
-      params.require(:tag).permit(:name, :trendable, :usable, :listable)
+      params.require(:tag).permit(:name, :display_name, :trendable, :usable, :listable)
     end
   end
 end
diff --git a/app/controllers/api/v1/featured_tags_controller.rb b/app/controllers/api/v1/featured_tags_controller.rb
index e4e836c97..c1ead4f54 100644
--- a/app/controllers/api/v1/featured_tags_controller.rb
+++ b/app/controllers/api/v1/featured_tags_controller.rb
@@ -13,9 +13,7 @@ class Api::V1::FeaturedTagsController < Api::BaseController
   end
 
   def create
-    @featured_tag = current_account.featured_tags.new(featured_tag_params)
-    @featured_tag.reset_data
-    @featured_tag.save!
+    @featured_tag = current_account.featured_tags.create!(featured_tag_params)
     render json: @featured_tag, serializer: REST::FeaturedTagSerializer
   end
 
diff --git a/app/controllers/settings/featured_tags_controller.rb b/app/controllers/settings/featured_tags_controller.rb
index e805527d0..aadff7c83 100644
--- a/app/controllers/settings/featured_tags_controller.rb
+++ b/app/controllers/settings/featured_tags_controller.rb
@@ -11,7 +11,6 @@ class Settings::FeaturedTagsController < Settings::BaseController
 
   def create
     @featured_tag = current_account.featured_tags.new(featured_tag_params)
-    @featured_tag.reset_data
 
     if @featured_tag.save
       redirect_to settings_featured_tags_path
diff --git a/app/javascript/mastodon/actions/compose.js b/app/javascript/mastodon/actions/compose.js
index bd4c1d002..32d8c229e 100644
--- a/app/javascript/mastodon/actions/compose.js
+++ b/app/javascript/mastodon/actions/compose.js
@@ -606,7 +606,20 @@ function insertIntoTagHistory(recognizedTags, text) {
     const state = getState();
     const oldHistory = state.getIn(['compose', 'tagHistory']);
     const me = state.getIn(['meta', 'me']);
-    const names = recognizedTags.map(tag => text.match(new RegExp(`#${tag.name}`, 'i'))[0].slice(1));
+
+    // FIXME: Matching input hashtags with recognized hashtags has become more
+    // complicated because of new normalization rules, it's no longer just
+    // a case sensitivity issue
+    const names = recognizedTags.map(tag => {
+      const matches = text.match(new RegExp(`#${tag.name}`, 'i'));
+
+      if (matches && matches.length > 0) {
+        return matches[0].slice(1);
+      } else {
+        return tag.name;
+      }
+    });
+
     const intersectedOldHistory = oldHistory.filter(name => names.findIndex(newName => newName.toLowerCase() === name.toLowerCase()) === -1);
 
     names.push(...intersectedOldHistory.toJS());
diff --git a/app/lib/ascii_folding.rb b/app/lib/ascii_folding.rb
new file mode 100644
index 000000000..1798d3d0e
--- /dev/null
+++ b/app/lib/ascii_folding.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class ASCIIFolding
+  NON_ASCII_CHARS        = 'ÀÁÂÃÄÅàáâãäåĀāĂ㥹ÇçĆćĈĉĊċČčÐðĎďĐđÈÉÊËèéêëĒēĔĕĖėĘęĚěĜĝĞğĠġĢģĤĥĦħÌÍÎÏìíîïĨĩĪīĬĭĮįİıĴĵĶķĸĹĺĻļĽľĿŀŁłÑñŃńŅņŇňʼnŊŋÒÓÔÕÖØòóôõöøŌōŎŏŐőŔŕŖŗŘřŚśŜŝŞşŠšſŢţŤťŦŧÙÚÛÜùúûüŨũŪūŬŭŮůŰűŲųŴŵÝýÿŶŷŸŹźŻżŽž'
+  EQUIVALENT_ASCII_CHARS = 'AAAAAAaaaaaaAaAaAaCcCcCcCcCcDdDdDdEEEEeeeeEeEeEeEeEeGgGgGgGgHhHhIIIIiiiiIiIiIiIiIiJjKkkLlLlLlLlLlNnNnNnNnnNnOOOOOOooooooOoOoOoRrRrRrSsSsSsSssTtTtTtUUUUuuuuUuUuUuUuUuUuWwYyyYyYZzZzZz'
+
+  def fold(str)
+    str.tr(NON_ASCII_CHARS, EQUIVALENT_ASCII_CHARS)
+  end
+end
diff --git a/app/lib/hashtag_normalizer.rb b/app/lib/hashtag_normalizer.rb
new file mode 100644
index 000000000..c1f99e163
--- /dev/null
+++ b/app/lib/hashtag_normalizer.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class HashtagNormalizer
+  def normalize(str)
+    remove_invalid_characters(ascii_folding(lowercase(cjk_width(str))))
+  end
+
+  private
+
+  def remove_invalid_characters(str)
+    str.gsub(/[^[:alnum:]#{Tag::HASHTAG_SEPARATORS}]/, '')
+  end
+
+  def ascii_folding(str)
+    ASCIIFolding.new.fold(str)
+  end
+
+  def lowercase(str)
+    str.mb_chars.downcase.to_s
+  end
+
+  def cjk_width(str)
+    str.unicode_normalize(:nfkc)
+  end
+end
diff --git a/app/models/account.rb b/app/models/account.rb
index 628692d22..fe77eaec4 100644
--- a/app/models/account.rb
+++ b/app/models/account.rb
@@ -62,7 +62,7 @@ class Account < ApplicationRecord
   )
 
   USERNAME_RE   = /[a-z0-9_]+([a-z0-9_\.-]+[a-z0-9_]+)?/i
-  MENTION_RE    = /(?<=^|[^\/[:word:]])@((#{USERNAME_RE})(?:@[[:word:]\.\-]+[[:word:]]+)?)/i
+  MENTION_RE    = /(?<=^|[^\/[:word:]])@((#{USERNAME_RE})(?:@[[:alnum:]\.\-]+[[:alnum:]]+)?)/i
   URL_PREFIX_RE = /\Ahttp(s?):\/\/[^\/]+/
 
   include Attachmentable
diff --git a/app/models/custom_filter.rb b/app/models/custom_filter.rb
index e98ed7df9..985eab125 100644
--- a/app/models/custom_filter.rb
+++ b/app/models/custom_filter.rb
@@ -3,14 +3,14 @@
 #
 # Table name: custom_filters
 #
-#  id         :bigint           not null, primary key
-#  account_id :bigint
+#  id         :bigint(8)        not null, primary key
+#  account_id :bigint(8)
 #  expires_at :datetime
 #  phrase     :text             default(""), not null
 #  context    :string           default([]), not null, is an Array
 #  created_at :datetime         not null
 #  updated_at :datetime         not null
-#  action     :integer          default(0), not null
+#  action     :integer          default("warn"), not null
 #
 
 class CustomFilter < ApplicationRecord
diff --git a/app/models/custom_filter_keyword.rb b/app/models/custom_filter_keyword.rb
index bf5c55746..e0d0289ae 100644
--- a/app/models/custom_filter_keyword.rb
+++ b/app/models/custom_filter_keyword.rb
@@ -3,8 +3,8 @@
 #
 # Table name: custom_filter_keywords
 #
-#  id               :bigint           not null, primary key
-#  custom_filter_id :bigint           not null
+#  id               :bigint(8)        not null, primary key
+#  custom_filter_id :bigint(8)        not null
 #  keyword          :text             default(""), not null
 #  whole_word       :boolean          default(TRUE), not null
 #  created_at       :datetime         not null
diff --git a/app/models/featured_tag.rb b/app/models/featured_tag.rb
index 74d62e777..c9c285bfa 100644
--- a/app/models/featured_tag.rb
+++ b/app/models/featured_tag.rb
@@ -13,17 +13,19 @@
 #
 
 class FeaturedTag < ApplicationRecord
-  belongs_to :account, inverse_of: :featured_tags, required: true
-  belongs_to :tag, inverse_of: :featured_tags, required: true
+  belongs_to :account, inverse_of: :featured_tags
+  belongs_to :tag, inverse_of: :featured_tags, optional: true # Set after validation
 
-  delegate :name, to: :tag, allow_nil: true
-
-  validates_associated :tag, on: :create
-  validates :name, presence: true, on: :create
+  validate :validate_tag_name, on: :create
   validate :validate_featured_tags_limit, on: :create
 
-  def name=(str)
-    self.tag = Tag.find_or_create_by_names(str.strip)&.first
+  before_create :set_tag
+  before_create :reset_data
+
+  attr_writer :name
+
+  def name
+    tag_id.present? ? tag.name : @name
   end
 
   def increment(timestamp)
@@ -34,14 +36,23 @@ class FeaturedTag < ApplicationRecord
     update(statuses_count: [0, statuses_count - 1].max, last_status_at: account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).where.not(id: deleted_status_id).select(:created_at).first&.created_at)
   end
 
+  private
+
+  def set_tag
+    self.tag = Tag.find_or_create_by_names(@name)&.first
+  end
+
   def reset_data
     self.statuses_count = account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).count
     self.last_status_at = account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).select(:created_at).first&.created_at
   end
 
-  private
-
   def validate_featured_tags_limit
     errors.add(:base, I18n.t('featured_tags.errors.limit')) if account.featured_tags.count >= 10
   end
+
+  def validate_tag_name
+    errors.add(:name, :blank) if @name.blank?
+    errors.add(:name, :invalid) unless @name.match?(/\A(#{Tag::HASHTAG_NAME_RE})\z/i)
+  end
 end
diff --git a/app/models/tag.rb b/app/models/tag.rb
index a64042614..f078007f2 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -15,6 +15,7 @@
 #  last_status_at      :datetime
 #  max_score           :float
 #  max_score_at        :datetime
+#  display_name        :string
 #
 
 class Tag < ApplicationRecord
@@ -24,11 +25,12 @@ class Tag < ApplicationRecord
   has_many :featured_tags, dependent: :destroy, inverse_of: :tag
 
   HASHTAG_SEPARATORS = "_\u00B7\u200c"
-  HASHTAG_NAME_RE    = "([[:word:]_][[:word:]#{HASHTAG_SEPARATORS}]*[[:alpha:]#{HASHTAG_SEPARATORS}][[:word:]#{HASHTAG_SEPARATORS}]*[[:word:]_])|([[:word:]_]*[[:alpha:]][[:word:]_]*)"
+  HASHTAG_NAME_RE    = "([[:alnum:]_][[:alnum:]#{HASHTAG_SEPARATORS}]*[[:alpha:]#{HASHTAG_SEPARATORS}][[:alnum:]#{HASHTAG_SEPARATORS}]*[[:alnum:]_])|([[:alnum:]_]*[[:alpha:]][[:alnum:]_]*)"
   HASHTAG_RE         = /(?:^|[^\/\)\w])#(#{HASHTAG_NAME_RE})/i
 
   validates :name, presence: true, format: { with: /\A(#{HASHTAG_NAME_RE})\z/i }
   validate :validate_name_change, if: -> { !new_record? && name_changed? }
+  validate :validate_display_name_change, if: -> { !new_record? && display_name_changed? }
 
   scope :reviewed, -> { where.not(reviewed_at: nil) }
   scope :unreviewed, -> { where(reviewed_at: nil) }
@@ -46,6 +48,10 @@ class Tag < ApplicationRecord
     name
   end
 
+  def display_name
+    attributes['display_name'] || name
+  end
+
   def usable
     boolean_with_default('usable', true)
   end
@@ -90,8 +96,10 @@ class Tag < ApplicationRecord
 
   class << self
     def find_or_create_by_names(name_or_names)
-      Array(name_or_names).map(&method(:normalize)).uniq { |str| str.mb_chars.downcase.to_s }.map do |normalized_name|
-        tag = matching_name(normalized_name).first || create(name: normalized_name)
+      names = Array(name_or_names).map { |str| [normalize(str), str] }.uniq(&:first)
+
+      names.map do |(normalized_name, display_name)|
+        tag = matching_name(normalized_name).first || create(name: normalized_name, display_name: display_name)
 
         yield tag if block_given?
 
@@ -129,7 +137,7 @@ class Tag < ApplicationRecord
     end
 
     def normalize(str)
-      str.gsub(/\A#/, '')
+      HashtagNormalizer.new.normalize(str)
     end
   end
 
@@ -138,4 +146,8 @@ class Tag < ApplicationRecord
   def validate_name_change
     errors.add(:name, I18n.t('tags.does_not_match_previous_name')) unless name_was.mb_chars.casecmp(name.mb_chars).zero?
   end
+
+  def validate_display_name_change
+    errors.add(:display_name, I18n.t('tags.does_not_match_previous_name')) unless HashtagNormalizer.new.normalize(display_name).casecmp(name.mb_chars).zero?
+  end
 end
diff --git a/app/serializers/activitypub/hashtag_serializer.rb b/app/serializers/activitypub/hashtag_serializer.rb
index 1a56e4dfe..90929c57f 100644
--- a/app/serializers/activitypub/hashtag_serializer.rb
+++ b/app/serializers/activitypub/hashtag_serializer.rb
@@ -10,11 +10,11 @@ class ActivityPub::HashtagSerializer < ActivityPub::Serializer
   end
 
   def name
-    "##{object.name}"
+    "##{object.display_name}"
   end
 
   def href
-    if object.class.name == 'FeaturedTag'
+    if object.instance_of?(FeaturedTag)
       short_account_tag_url(object.account, object.tag)
     else
       tag_url(object)
diff --git a/app/serializers/rest/featured_tag_serializer.rb b/app/serializers/rest/featured_tag_serializer.rb
index 96adcc7d0..8abcd9b90 100644
--- a/app/serializers/rest/featured_tag_serializer.rb
+++ b/app/serializers/rest/featured_tag_serializer.rb
@@ -12,4 +12,8 @@ class REST::FeaturedTagSerializer < ActiveModel::Serializer
   def url
     short_account_tag_url(object.account, object.tag)
   end
+
+  def name
+    object.display_name
+  end
 end
diff --git a/app/serializers/rest/tag_serializer.rb b/app/serializers/rest/tag_serializer.rb
index 74aa571a4..52bfaa4ce 100644
--- a/app/serializers/rest/tag_serializer.rb
+++ b/app/serializers/rest/tag_serializer.rb
@@ -8,4 +8,8 @@ class REST::TagSerializer < ActiveModel::Serializer
   def url
     tag_url(object)
   end
+
+  def name
+    object.display_name
+  end
 end
diff --git a/app/views/accounts/show.html.haml b/app/views/accounts/show.html.haml
index 72e9c6611..7fa688bd3 100644
--- a/app/views/accounts/show.html.haml
+++ b/app/views/accounts/show.html.haml
@@ -75,7 +75,7 @@
           = link_to short_account_tag_path(@account, featured_tag.tag) do
             %h4
               = fa_icon 'hashtag'
-              = featured_tag.name
+              = featured_tag.display_name
               %small
                 - if featured_tag.last_status_at.nil?
                   = t('accounts.nothing_here')
diff --git a/app/views/accounts/show.rss.ruby b/app/views/accounts/show.rss.ruby
index fd45a8b2b..34e29d483 100644
--- a/app/views/accounts/show.rss.ruby
+++ b/app/views/accounts/show.rss.ruby
@@ -28,7 +28,7 @@ RSS::Builder.build do |doc|
       end
 
       status.tags.each do |tag|
-        item.category(tag.name)
+        item.category(tag.display_name)
       end
     end
   end
diff --git a/app/views/admin/tags/show.html.haml b/app/views/admin/tags/show.html.haml
index fd9acce4a..104190b58 100644
--- a/app/views/admin/tags/show.html.haml
+++ b/app/views/admin/tags/show.html.haml
@@ -2,7 +2,7 @@
   = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
 
 - content_for :page_title do
-  = "##{@tag.name}"
+  = "##{@tag.display_name}"
 
 - if current_user.can?(:view_dashboard)
   - content_for :heading_actions do
@@ -53,7 +53,7 @@
   = render 'shared/error_messages', object: @tag
 
   .fields-group
-    = f.input :name, wrapper: :with_block_label
+    = f.input :display_name, wrapper: :with_block_label
 
   .fields-group
     = f.input :usable, as: :boolean, wrapper: :with_label
diff --git a/app/views/admin/trends/tags/_tag.html.haml b/app/views/admin/trends/tags/_tag.html.haml
index 7bb99b158..a30666a08 100644
--- a/app/views/admin/trends/tags/_tag.html.haml
+++ b/app/views/admin/trends/tags/_tag.html.haml
@@ -6,7 +6,7 @@
     .pending-account__header
       = link_to admin_tag_path(tag.id) do
         = fa_icon 'hashtag'
-        = tag.name
+        = tag.display_name
 
       %br/
 
diff --git a/app/views/admin_mailer/_new_trending_tags.text.erb b/app/views/admin_mailer/_new_trending_tags.text.erb
index cde5af4e4..363df369d 100644
--- a/app/views/admin_mailer/_new_trending_tags.text.erb
+++ b/app/views/admin_mailer/_new_trending_tags.text.erb
@@ -1,12 +1,12 @@
 <%= raw t('admin_mailer.new_trends.new_trending_tags.title') %>
 
 <% @tags.each do |tag| %>
-- #<%= tag.name %>
+- #<%= tag.display_name %>
   <%= raw t('admin.trends.tags.usage_comparison', today: tag.history.get(Time.now.utc).accounts, yesterday: tag.history.get(Time.now.utc - 1.day).accounts) %> • <%= t('admin.trends.tags.current_score', score: Trends.tags.score(tag.id).round(2)) %>
 <% end %>
 
 <% if @lowest_trending_tag %>
-<%= raw t('admin_mailer.new_trends.new_trending_tags.requirements', lowest_tag_name: @lowest_trending_tag.name, lowest_tag_score: Trends.tags.score(@lowest_trending_tag.id).round(2), rank: Trends.tags.options[:review_threshold]) %>
+<%= raw t('admin_mailer.new_trends.new_trending_tags.requirements', lowest_tag_name: @lowest_trending_tag.display_name, lowest_tag_score: Trends.tags.score(@lowest_trending_tag.id).round(2), rank: Trends.tags.options[:review_threshold]) %>
 <% else %>
 <%= raw t('admin_mailer.new_trends.new_trending_tags.no_approved_tags') %>
 <% end %>
diff --git a/app/views/settings/featured_tags/index.html.haml b/app/views/settings/featured_tags/index.html.haml
index 65de7f8f3..5d87e2862 100644
--- a/app/views/settings/featured_tags/index.html.haml
+++ b/app/views/settings/featured_tags/index.html.haml
@@ -9,7 +9,7 @@
   = render 'shared/error_messages', object: @featured_tag
 
   .fields-group
-    = f.input :name, wrapper: :with_block_label, hint: safe_join([t('simple_form.hints.featured_tag.name'), safe_join(@recently_used_tags.map { |tag| link_to("##{tag.name}", settings_featured_tags_path(featured_tag: { name: tag.name }), method: :post) }, ', ')], ' ')
+    = f.input :name, wrapper: :with_block_label, hint: safe_join([t('simple_form.hints.featured_tag.name'), safe_join(@recently_used_tags.map { |tag| link_to("##{tag.display_name}", settings_featured_tags_path(featured_tag: { name: tag.name }), method: :post) }, ', ')], ' ')
 
   .actions
     = f.button :button, t('featured_tags.add_new'), type: :submit
diff --git a/app/views/tags/_og.html.haml b/app/views/tags/_og.html.haml
index a7c289bcb..37f644cf2 100644
--- a/app/views/tags/_og.html.haml
+++ b/app/views/tags/_og.html.haml
@@ -1,6 +1,6 @@
 = opengraph 'og:site_name', t('about.hosted_on', domain: site_hostname)
 = opengraph 'og:url', tag_url(@tag)
 = opengraph 'og:type', 'website'
-= opengraph 'og:title', "##{@tag.name}"
-= opengraph 'og:description', strip_tags(t('about.about_hashtag_html', hashtag: @tag.name))
+= opengraph 'og:title', "##{@tag.display_name}"
+= opengraph 'og:description', strip_tags(t('about.about_hashtag_html', hashtag: @tag.display_name))
 = opengraph 'twitter:card', 'summary'
diff --git a/app/views/tags/show.html.haml b/app/views/tags/show.html.haml
index 5cd513b32..6dfb4f9b3 100644
--- a/app/views/tags/show.html.haml
+++ b/app/views/tags/show.html.haml
@@ -1,5 +1,5 @@
 - content_for :page_title do
-  = "##{@tag.name}"
+  = "##{@tag.display_name}"
 
 - content_for :header_tags do
   %meta{ name: 'robots', content: 'noindex' }/
@@ -9,8 +9,8 @@
   = render 'og'
 
 .page-header
-  %h1= "##{@tag.name}"
-  %p= t('about.about_hashtag_html', hashtag: @tag.name)
+  %h1= "##{@tag.display_name}"
+  %p= t('about.about_hashtag_html', hashtag: @tag.display_name)
 
 #mastodon-timeline{ data: { props: Oj.dump(default_props.merge(hashtag: @tag.name, local: @local)) }}
 .notranslate#modal-container
diff --git a/app/views/tags/show.rss.ruby b/app/views/tags/show.rss.ruby
index 9ce71be74..8e0c2327b 100644
--- a/app/views/tags/show.rss.ruby
+++ b/app/views/tags/show.rss.ruby
@@ -1,6 +1,6 @@
 RSS::Builder.build do |doc|
-  doc.title("##{@tag.name}")
-  doc.description(I18n.t('rss.descriptions.tag', hashtag: @tag.name))
+  doc.title("##{@tag.display_name}")
+  doc.description(I18n.t('rss.descriptions.tag', hashtag: @tag.display_name))
   doc.link(tag_url(@tag))
   doc.last_build_date(@statuses.first.created_at) if @statuses.any?
   doc.generator("Mastodon v#{Mastodon::Version.to_s}")
@@ -26,7 +26,7 @@ RSS::Builder.build do |doc|
       end
 
       status.tags.each do |tag|
-        item.category(tag.name)
+        item.category(tag.display_name)
       end
     end
   end
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
index 9bc9a54b2..3e5a55617 100644
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -24,6 +24,7 @@ ActiveSupport::Inflector.inflections(:en) do |inflect|
   inflect.acronym 'RSS'
   inflect.acronym 'REST'
   inflect.acronym 'URL'
+  inflect.acronym 'ASCII'
 
   inflect.singular 'data', 'data'
 end
diff --git a/db/migrate/20220710102457_add_display_name_to_tags.rb b/db/migrate/20220710102457_add_display_name_to_tags.rb
new file mode 100644
index 000000000..aa7867645
--- /dev/null
+++ b/db/migrate/20220710102457_add_display_name_to_tags.rb
@@ -0,0 +1,5 @@
+class AddDisplayNameToTags < ActiveRecord::Migration[6.1]
+  def change
+    add_column :tags, :display_name, :string
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 54966ef64..9b465b674 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2022_07_04_024901) do
+ActiveRecord::Schema.define(version: 2022_07_10_102457) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -940,6 +940,7 @@ ActiveRecord::Schema.define(version: 2022_07_04_024901) do
     t.datetime "last_status_at"
     t.float "max_score"
     t.datetime "max_score_at"
+    t.string "display_name"
     t.index "lower((name)::text) text_pattern_ops", name: "index_tags_on_name_lower_btree", unique: true
   end
 
diff --git a/spec/lib/hashtag_normalizer_spec.rb b/spec/lib/hashtag_normalizer_spec.rb
new file mode 100644
index 000000000..fbb9f37c0
--- /dev/null
+++ b/spec/lib/hashtag_normalizer_spec.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe HashtagNormalizer do
+  subject { described_class.new }
+
+  describe '#normalize' do
+    it 'converts full-width Latin characters into basic Latin characters' do
+      expect(subject.normalize('Ｓｙｎｔｈｗａｖｅ')).to eq 'synthwave'
+    end
+
+    it 'converts half-width Katakana into Kana characters' do
+      expect(subject.normalize('ｼｰｻｲﾄﾞﾗｲﾅｰ')).to eq 'シーサイドライナー'
+    end
+
+    it 'converts modified Latin characters into basic Latin characters' do
+      expect(subject.normalize('BLÅHAJ')).to eq 'blahaj'
+    end
+
+    it 'strips out invalid characters' do
+      expect(subject.normalize('#foo')).to eq 'foo'
+    end
+
+    it 'keeps valid characters' do
+      expect(subject.normalize('a·b')).to eq 'a·b'
+    end
+  end
+end
diff --git a/spec/models/tag_spec.rb b/spec/models/tag_spec.rb
index 3949dbce5..b16f99a79 100644
--- a/spec/models/tag_spec.rb
+++ b/spec/models/tag_spec.rb
@@ -91,7 +91,7 @@ RSpec.describe Tag, type: :model do
       upcase_string   = 'abcABCａｂｃＡＢＣやゆよ'
       downcase_string = 'abcabcａｂｃａｂｃやゆよ';
 
-      tag = Fabricate(:tag, name: downcase_string)
+      tag = Fabricate(:tag, name: HashtagNormalizer.new.normalize(downcase_string))
       expect(Tag.find_normalized(upcase_string)).to eq tag
     end
   end
@@ -101,12 +101,12 @@ RSpec.describe Tag, type: :model do
       upcase_string   = 'abcABCａｂｃＡＢＣやゆよ'
       downcase_string = 'abcabcａｂｃａｂｃやゆよ';
 
-      tag = Fabricate(:tag, name: downcase_string)
+      tag = Fabricate(:tag, name: HashtagNormalizer.new.normalize(downcase_string))
       expect(Tag.matches_name(upcase_string)).to eq [tag]
     end
 
     it 'uses the LIKE operator' do
-      expect(Tag.matches_name('100%abc').to_sql).to eq %q[SELECT "tags".* FROM "tags" WHERE LOWER("tags"."name") LIKE LOWER('100\\%abc%')]
+      expect(Tag.matches_name('100%abc').to_sql).to eq %q[SELECT "tags".* FROM "tags" WHERE LOWER("tags"."name") LIKE LOWER('100abc%')]
     end
   end
 
@@ -115,7 +115,7 @@ RSpec.describe Tag, type: :model do
       upcase_string   = 'abcABCａｂｃＡＢＣやゆよ'
       downcase_string = 'abcabcａｂｃａｂｃやゆよ';
 
-      tag = Fabricate(:tag, name: downcase_string)
+      tag = Fabricate(:tag, name: HashtagNormalizer.new.normalize(downcase_string))
       expect(Tag.matching_name(upcase_string)).to eq [tag]
     end
   end
diff --git a/streaming/index.js b/streaming/index.js
index 792ec5a44..a55181bad 100644
--- a/streaming/index.js
+++ b/streaming/index.js
@@ -892,6 +892,34 @@ const startWorker = async (workerId) => {
     return arr;
   };
 
+  /**
+   * See app/lib/ascii_folder.rb for the canon definitions
+   * of these constants
+   */
+  const NON_ASCII_CHARS        = 'ÀÁÂÃÄÅàáâãäåĀāĂ㥹ÇçĆćĈĉĊċČčÐðĎďĐđÈÉÊËèéêëĒēĔĕĖėĘęĚěĜĝĞğĠġĢģĤĥĦħÌÍÎÏìíîïĨĩĪīĬĭĮįİıĴĵĶķĸĹĺĻļĽľĿŀŁłÑñŃńŅņŇňʼnŊŋÒÓÔÕÖØòóôõöøŌōŎŏŐőŔŕŖŗŘřŚśŜŝŞşŠšſŢţŤťŦŧÙÚÛÜùúûüŨũŪūŬŭŮůŰűŲųŴŵÝýÿŶŷŸŹźŻżŽž';
+  const EQUIVALENT_ASCII_CHARS = 'AAAAAAaaaaaaAaAaAaCcCcCcCcCcDdDdDdEEEEeeeeEeEeEeEeEeGgGgGgGgHhHhIIIIiiiiIiIiIiIiIiJjKkkLlLlLlLlLlNnNnNnNnnNnOOOOOOooooooOoOoOoRrRrRrSsSsSsSssTtTtTtUUUUuuuuUuUuUuUuUuUuWwYyyYyYZzZzZz';
+
+  /**
+   * @param {string} str
+   * @return {string}
+   */
+  const foldToASCII = str => {
+    const regex = new RegExp(NON_ASCII_CHARS.split('').join('|'), 'g');
+
+    return str.replace(regex, match => {
+      const index = NON_ASCII_CHARS.indexOf(match);
+      return EQUIVALENT_ASCII_CHARS[index];
+    });
+  };
+
+  /**
+   * @param {string} str
+   * @return {string}
+   */
+  const normalizeHashtag = str => {
+    return foldToASCII(str.normalize('NFKC').toLowerCase()).replace(/[^\p{L}\p{N}_\u00b7\u200c]/gu, '');
+  };
+
   /**
    * @param {any} req
    * @param {string} name
@@ -968,7 +996,7 @@ const startWorker = async (workerId) => {
         reject('No tag for stream provided');
       } else {
         resolve({
-          channelIds: [`timeline:hashtag:${params.tag.toLowerCase()}`],
+          channelIds: [`timeline:hashtag:${normalizeHashtag(params.tag)}`],
           options: { needsFiltering: true },
         });
       }
@@ -979,7 +1007,7 @@ const startWorker = async (workerId) => {
         reject('No tag for stream provided');
       } else {
         resolve({
-          channelIds: [`timeline:hashtag:${params.tag.toLowerCase()}:local`],
+          channelIds: [`timeline:hashtag:${normalizeHashtag(params.tag)}:local`],
           options: { needsFiltering: true },
         });
       }
-- 
cgit 


From c3f0621a59a74d0e20e6db6170894871c48e8f0f Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Sun, 17 Jul 2022 13:49:29 +0200
Subject: Add ability to follow hashtags (#18809)

---
 .../api/v1/featured_tags/suggestions_controller.rb |  2 +-
 app/controllers/api/v1/followed_tags_controller.rb | 52 ++++++++++++++
 app/controllers/api/v1/tags_controller.rb          | 29 ++++++++
 app/controllers/api/v1/trends/tags_controller.rb   |  2 +-
 app/lib/feed_manager.rb                            | 36 ++++++----
 app/models/tag.rb                                  |  5 +-
 app/models/tag_follow.rb                           | 24 +++++++
 app/presenters/tag_relationships_presenter.rb      | 15 ++++
 app/serializers/rest/tag_serializer.rb             | 14 ++++
 app/services/fan_out_on_write_service.rb           | 15 +++-
 app/workers/feed_insert_worker.rb                  |  8 ++-
 config/routes.rb                                   |  9 +++
 db/migrate/20220714171049_create_tag_follows.rb    | 12 ++++
 db/schema.rb                                       | 13 +++-
 .../api/v1/followed_tags_controller_spec.rb        | 23 ++++++
 spec/controllers/api/v1/tags_controller_spec.rb    | 82 ++++++++++++++++++++++
 spec/fabricators/tag_follow_fabricator.rb          |  4 ++
 spec/models/tag_follow_spec.rb                     |  4 ++
 18 files changed, 329 insertions(+), 20 deletions(-)
 create mode 100644 app/controllers/api/v1/followed_tags_controller.rb
 create mode 100644 app/controllers/api/v1/tags_controller.rb
 create mode 100644 app/models/tag_follow.rb
 create mode 100644 app/presenters/tag_relationships_presenter.rb
 create mode 100644 db/migrate/20220714171049_create_tag_follows.rb
 create mode 100644 spec/controllers/api/v1/followed_tags_controller_spec.rb
 create mode 100644 spec/controllers/api/v1/tags_controller_spec.rb
 create mode 100644 spec/fabricators/tag_follow_fabricator.rb
 create mode 100644 spec/models/tag_follow_spec.rb

(limited to 'app/controllers/api/v1')

diff --git a/app/controllers/api/v1/featured_tags/suggestions_controller.rb b/app/controllers/api/v1/featured_tags/suggestions_controller.rb
index 75545d3c7..76633210a 100644
--- a/app/controllers/api/v1/featured_tags/suggestions_controller.rb
+++ b/app/controllers/api/v1/featured_tags/suggestions_controller.rb
@@ -6,7 +6,7 @@ class Api::V1::FeaturedTags::SuggestionsController < Api::BaseController
   before_action :set_recently_used_tags, only: :index
 
   def index
-    render json: @recently_used_tags, each_serializer: REST::TagSerializer
+    render json: @recently_used_tags, each_serializer: REST::TagSerializer, relationships: TagRelationshipsPresenter.new(@recently_used_tags, current_user&.account_id)
   end
 
   private
diff --git a/app/controllers/api/v1/followed_tags_controller.rb b/app/controllers/api/v1/followed_tags_controller.rb
new file mode 100644
index 000000000..f0dfd044c
--- /dev/null
+++ b/app/controllers/api/v1/followed_tags_controller.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+class Api::V1::FollowedTagsController < Api::BaseController
+  TAGS_LIMIT = 100
+
+  before_action -> { doorkeeper_authorize! :follow, :read, :'read:follows' }, except: :show
+  before_action :require_user!
+  before_action :set_results
+
+  after_action :insert_pagination_headers, only: :show
+
+  def index
+    render json: @results.map(&:tag), each_serializer: REST::TagSerializer, relationships: TagRelationshipsPresenter.new(@results.map(&:tag), current_user&.account_id)
+  end
+
+  private
+
+  def set_results
+    @results = TagFollow.where(account: current_account).joins(:tag).eager_load(:tag).to_a_paginated_by_id(
+      limit_param(TAGS_LIMIT),
+      params_slice(:max_id, :since_id, :min_id)
+    )
+  end
+
+  def insert_pagination_headers
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def next_path
+    api_v1_followed_tags_url pagination_params(max_id: pagination_max_id) if records_continue?
+  end
+
+  def prev_path
+    api_v1_followed_tags_url pagination_params(since_id: pagination_since_id) unless @results.empty?
+  end
+
+  def pagination_max_id
+    @results.last.id
+  end
+
+  def pagination_since_id
+    @results.first.id
+  end
+
+  def records_continue?
+    @results.size == limit_param(TAG_LIMIT)
+  end
+
+  def pagination_params(core_params)
+    params.slice(:limit).permit(:limit).merge(core_params)
+  end
+end
diff --git a/app/controllers/api/v1/tags_controller.rb b/app/controllers/api/v1/tags_controller.rb
new file mode 100644
index 000000000..d45015ff5
--- /dev/null
+++ b/app/controllers/api/v1/tags_controller.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class Api::V1::TagsController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :follow, :write, :'write:follows' }, except: :show
+  before_action :require_user!, except: :show
+  before_action :set_or_create_tag
+
+  override_rate_limit_headers :follow, family: :follows
+
+  def show
+    render json: @tag, serializer: REST::TagSerializer
+  end
+
+  def follow
+    TagFollow.create!(tag: @tag, account: current_account, rate_limit: true)
+    render json: @tag, serializer: REST::TagSerializer
+  end
+
+  def unfollow
+    TagFollow.find_by(account: current_account, tag: @tag)&.destroy!
+    render json: @tag, serializer: REST::TagSerializer
+  end
+
+  private
+
+  def set_or_create_tag
+    @tag = Tag.find_normalized(params[:id]) || Tag.new(name: Tag.normalize(params[:id]), display_name: params[:id])
+  end
+end
diff --git a/app/controllers/api/v1/trends/tags_controller.rb b/app/controllers/api/v1/trends/tags_controller.rb
index 41f9ffac1..21adfa2a1 100644
--- a/app/controllers/api/v1/trends/tags_controller.rb
+++ b/app/controllers/api/v1/trends/tags_controller.rb
@@ -8,7 +8,7 @@ class Api::V1::Trends::TagsController < Api::BaseController
   DEFAULT_TAGS_LIMIT = 10
 
   def index
-    render json: @tags, each_serializer: REST::TagSerializer
+    render json: @tags, each_serializer: REST::TagSerializer, relationships: TagRelationshipsPresenter.new(@tags, current_user&.account_id)
   end
 
   private
diff --git a/app/lib/feed_manager.rb b/app/lib/feed_manager.rb
index 2eb4ba2f4..145352fe8 100644
--- a/app/lib/feed_manager.rb
+++ b/app/lib/feed_manager.rb
@@ -45,6 +45,8 @@ class FeedManager
       filter_from_list?(status, receiver) || filter_from_home?(status, receiver.account_id, build_crutches(receiver.account_id, [status]))
     when :mentions
       filter_from_mentions?(status, receiver.id)
+    when :tags
+      filter_from_tags?(status, receiver.id, build_crutches(receiver.id, [status]))
     else
       false
     end
@@ -56,7 +58,7 @@ class FeedManager
   # @param [Boolean] update
   # @return [Boolean]
   def push_to_home(account, status, update: false)
-    return false unless add_to_feed(:home, account.id, status, account.user&.aggregates_reblogs?)
+    return false unless add_to_feed(:home, account.id, status, aggregate_reblogs: account.user&.aggregates_reblogs?)
 
     trim(:home, account.id)
     PushUpdateWorker.perform_async(account.id, status.id, "timeline:#{account.id}", { 'update' => update }) if push_update_required?("timeline:#{account.id}")
@@ -69,7 +71,7 @@ class FeedManager
   # @param [Boolean] update
   # @return [Boolean]
   def unpush_from_home(account, status, update: false)
-    return false unless remove_from_feed(:home, account.id, status, account.user&.aggregates_reblogs?)
+    return false unless remove_from_feed(:home, account.id, status, aggregate_reblogs: account.user&.aggregates_reblogs?)
 
     redis.publish("timeline:#{account.id}", Oj.dump(event: :delete, payload: status.id.to_s)) unless update
     true
@@ -81,7 +83,7 @@ class FeedManager
   # @param [Boolean] update
   # @return [Boolean]
   def push_to_list(list, status, update: false)
-    return false if filter_from_list?(status, list) || !add_to_feed(:list, list.id, status, list.account.user&.aggregates_reblogs?)
+    return false if filter_from_list?(status, list) || !add_to_feed(:list, list.id, status, aggregate_reblogs: list.account.user&.aggregates_reblogs?)
 
     trim(:list, list.id)
     PushUpdateWorker.perform_async(list.account_id, status.id, "timeline:list:#{list.id}", { 'update' => update }) if push_update_required?("timeline:list:#{list.id}")
@@ -94,7 +96,7 @@ class FeedManager
   # @param [Boolean] update
   # @return [Boolean]
   def unpush_from_list(list, status, update: false)
-    return false unless remove_from_feed(:list, list.id, status, list.account.user&.aggregates_reblogs?)
+    return false unless remove_from_feed(:list, list.id, status, aggregate_reblogs: list.account.user&.aggregates_reblogs?)
 
     redis.publish("timeline:list:#{list.id}", Oj.dump(event: :delete, payload: status.id.to_s)) unless update
     true
@@ -120,7 +122,7 @@ class FeedManager
     statuses.each do |status|
       next if filter_from_home?(status, into_account.id, crutches)
 
-      add_to_feed(:home, into_account.id, status, aggregate)
+      add_to_feed(:home, into_account.id, status, aggregate_reblogs: aggregate)
     end
 
     trim(:home, into_account.id)
@@ -146,7 +148,7 @@ class FeedManager
     statuses.each do |status|
       next if filter_from_home?(status, list.account_id, crutches) || filter_from_list?(status, list)
 
-      add_to_feed(:list, list.id, status, aggregate)
+      add_to_feed(:list, list.id, status, aggregate_reblogs: aggregate)
     end
 
     trim(:list, list.id)
@@ -161,7 +163,7 @@ class FeedManager
     timeline_status_ids = redis.zrange(timeline_key, 0, -1)
 
     from_account.statuses.select('id, reblog_of_id').where(id: timeline_status_ids).reorder(nil).find_each do |status|
-      remove_from_feed(:home, into_account.id, status, into_account.user&.aggregates_reblogs?)
+      remove_from_feed(:home, into_account.id, status, aggregate_reblogs: into_account.user&.aggregates_reblogs?)
     end
   end
 
@@ -174,7 +176,7 @@ class FeedManager
     timeline_status_ids = redis.zrange(timeline_key, 0, -1)
 
     from_account.statuses.select('id, reblog_of_id').where(id: timeline_status_ids).reorder(nil).find_each do |status|
-      remove_from_feed(:list, list.id, status, list.account.user&.aggregates_reblogs?)
+      remove_from_feed(:list, list.id, status, aggregate_reblogs: list.account.user&.aggregates_reblogs?)
     end
   end
 
@@ -237,7 +239,7 @@ class FeedManager
     timeline_key = key(:home, account.id)
 
     account.statuses.limit(limit).each do |status|
-      add_to_feed(:home, account.id, status, aggregate)
+      add_to_feed(:home, account.id, status, aggregate_reblogs: aggregate)
     end
 
     account.following.includes(:account_stat).find_each do |target_account|
@@ -257,7 +259,7 @@ class FeedManager
       statuses.each do |status|
         next if filter_from_home?(status, account.id, crutches)
 
-        add_to_feed(:home, account.id, status, aggregate)
+        add_to_feed(:home, account.id, status, aggregate_reblogs: aggregate)
       end
 
       trim(:home, account.id)
@@ -416,6 +418,16 @@ class FeedManager
     false
   end
 
+  # Check if a status should not be added to the home feed when it comes
+  # from a followed hashtag
+  # @param [Status] status
+  # @param [Integer] receiver_id
+  # @param [Hash] crutches
+  # @return [Boolean]
+  def filter_from_tags?(status, receiver_id, crutches)
+    receiver_id != status.account_id && (((crutches[:active_mentions][status.id] || []) + [status.account_id]).any? { |target_account_id| crutches[:blocking][target_account_id] || crutches[:muting][target_account_id] } || crutches[:blocked_by][status.account_id] || crutches[:domain_blocking][status.account.domain])
+  end
+
   # Adds a status to an account's feed, returning true if a status was
   # added, and false if it was not added to the feed. Note that this is
   # an internal helper: callers must call trim or push updates if
@@ -425,7 +437,7 @@ class FeedManager
   # @param [Status] status
   # @param [Boolean] aggregate_reblogs
   # @return [Boolean]
-  def add_to_feed(timeline_type, account_id, status, aggregate_reblogs = true)
+  def add_to_feed(timeline_type, account_id, status, aggregate_reblogs: true)
     timeline_key = key(timeline_type, account_id)
     reblog_key   = key(timeline_type, account_id, 'reblogs')
 
@@ -473,7 +485,7 @@ class FeedManager
   # @param [Status] status
   # @param [Boolean] aggregate_reblogs
   # @return [Boolean]
-  def remove_from_feed(timeline_type, account_id, status, aggregate_reblogs = true)
+  def remove_from_feed(timeline_type, account_id, status, aggregate_reblogs: true)
     timeline_key = key(timeline_type, account_id)
     reblog_key   = key(timeline_type, account_id, 'reblogs')
 
diff --git a/app/models/tag.rb b/app/models/tag.rb
index f078007f2..eebf3b47d 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -22,13 +22,16 @@ class Tag < ApplicationRecord
   has_and_belongs_to_many :statuses
   has_and_belongs_to_many :accounts
 
+  has_many :passive_relationships, class_name: 'TagFollow', inverse_of: :tag, dependent: :destroy
   has_many :featured_tags, dependent: :destroy, inverse_of: :tag
+  has_many :followers, through: :passive_relationships, source: :account
 
   HASHTAG_SEPARATORS = "_\u00B7\u200c"
   HASHTAG_NAME_RE    = "([[:alnum:]_][[:alnum:]#{HASHTAG_SEPARATORS}]*[[:alpha:]#{HASHTAG_SEPARATORS}][[:alnum:]#{HASHTAG_SEPARATORS}]*[[:alnum:]_])|([[:alnum:]_]*[[:alpha:]][[:alnum:]_]*)"
   HASHTAG_RE         = /(?:^|[^\/\)\w])#(#{HASHTAG_NAME_RE})/i
 
   validates :name, presence: true, format: { with: /\A(#{HASHTAG_NAME_RE})\z/i }
+  validates :display_name, format: { with: /\A(#{HASHTAG_NAME_RE})\z/i }
   validate :validate_name_change, if: -> { !new_record? && name_changed? }
   validate :validate_display_name_change, if: -> { !new_record? && display_name_changed? }
 
@@ -99,7 +102,7 @@ class Tag < ApplicationRecord
       names = Array(name_or_names).map { |str| [normalize(str), str] }.uniq(&:first)
 
       names.map do |(normalized_name, display_name)|
-        tag = matching_name(normalized_name).first || create(name: normalized_name, display_name: display_name)
+        tag = matching_name(normalized_name).first || create(name: normalized_name, display_name: display_name.gsub(/[^[:alnum:]#{HASHTAG_SEPARATORS}]/, ''))
 
         yield tag if block_given?
 
diff --git a/app/models/tag_follow.rb b/app/models/tag_follow.rb
new file mode 100644
index 000000000..abe36cd17
--- /dev/null
+++ b/app/models/tag_follow.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: tag_follows
+#
+#  id         :bigint(8)        not null, primary key
+#  tag_id     :bigint(8)        not null
+#  account_id :bigint(8)        not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+
+class TagFollow < ApplicationRecord
+  include RateLimitable
+  include Paginable
+
+  belongs_to :tag
+  belongs_to :account
+
+  accepts_nested_attributes_for :tag
+
+  rate_limit by: :account, family: :follows
+end
diff --git a/app/presenters/tag_relationships_presenter.rb b/app/presenters/tag_relationships_presenter.rb
new file mode 100644
index 000000000..c3bdbaf07
--- /dev/null
+++ b/app/presenters/tag_relationships_presenter.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class TagRelationshipsPresenter
+  attr_reader :following_map
+
+  def initialize(tags, current_account_id = nil, **options)
+    @following_map = begin
+      if current_account_id.nil?
+        {}
+      else
+        TagFollow.select(:tag_id).where(tag_id: tags.map(&:id), account_id: current_account_id).each_with_object({}) { |f, h| h[f.tag_id] = true }.merge(options[:following_map] || {})
+      end
+    end
+  end
+end
diff --git a/app/serializers/rest/tag_serializer.rb b/app/serializers/rest/tag_serializer.rb
index 52bfaa4ce..7801e77d1 100644
--- a/app/serializers/rest/tag_serializer.rb
+++ b/app/serializers/rest/tag_serializer.rb
@@ -5,6 +5,8 @@ class REST::TagSerializer < ActiveModel::Serializer
 
   attributes :name, :url, :history
 
+  attribute :following, if: :current_user?
+
   def url
     tag_url(object)
   end
@@ -12,4 +14,16 @@ class REST::TagSerializer < ActiveModel::Serializer
   def name
     object.display_name
   end
+
+  def following
+    if instance_options && instance_options[:relationships]
+      instance_options[:relationships].following_map[object.id] || false
+    else
+      TagFollow.where(tag_id: object.id, account_id: current_user.account_id).exists?
+    end
+  end
+
+  def current_user?
+    !current_user.nil?
+  end
 end
diff --git a/app/services/fan_out_on_write_service.rb b/app/services/fan_out_on_write_service.rb
index de5c5ebe4..ce20a146e 100644
--- a/app/services/fan_out_on_write_service.rb
+++ b/app/services/fan_out_on_write_service.rb
@@ -16,6 +16,7 @@ class FanOutOnWriteService < BaseService
     check_race_condition!
 
     fan_out_to_local_recipients!
+    fan_out_to_public_recipients! if broadcastable?
     fan_out_to_public_streams! if broadcastable?
   end
 
@@ -50,6 +51,10 @@ class FanOutOnWriteService < BaseService
     end
   end
 
+  def fan_out_to_public_recipients!
+    deliver_to_hashtag_followers!
+  end
+
   def fan_out_to_public_streams!
     broadcast_to_hashtag_streams!
     broadcast_to_public_streams!
@@ -83,6 +88,14 @@ class FanOutOnWriteService < BaseService
     end
   end
 
+  def deliver_to_hashtag_followers!
+    TagFollow.where(tag_id: @status.tags.map(&:id)).select(:id, :account_id).reorder(nil).find_in_batches do |follows|
+      FeedInsertWorker.push_bulk(follows) do |follow|
+        [@status.id, follow.account_id, 'tags', { 'update' => update? }]
+      end
+    end
+  end
+
   def deliver_to_lists!
     @account.lists_for_local_distribution.select(:id).reorder(nil).find_in_batches do |lists|
       FeedInsertWorker.push_bulk(lists) do |list|
@@ -100,7 +113,7 @@ class FanOutOnWriteService < BaseService
   end
 
   def broadcast_to_hashtag_streams!
-    @status.tags.pluck(:name).each do |hashtag|
+    @status.tags.map(&:name).each do |hashtag|
       redis.publish("timeline:hashtag:#{hashtag.mb_chars.downcase}", anonymous_payload)
       redis.publish("timeline:hashtag:#{hashtag.mb_chars.downcase}:local", anonymous_payload) if @status.local?
     end
diff --git a/app/workers/feed_insert_worker.rb b/app/workers/feed_insert_worker.rb
index 40bc9cb6e..758cebd4b 100644
--- a/app/workers/feed_insert_worker.rb
+++ b/app/workers/feed_insert_worker.rb
@@ -9,7 +9,7 @@ class FeedInsertWorker
     @options   = options.symbolize_keys
 
     case @type
-    when :home
+    when :home, :tags
       @follower = Account.find(id)
     when :list
       @list     = List.find(id)
@@ -36,6 +36,8 @@ class FeedInsertWorker
     case @type
     when :home
       FeedManager.instance.filter?(:home, @status, @follower)
+    when :tags
+      FeedManager.instance.filter?(:tags, @status, @follower)
     when :list
       FeedManager.instance.filter?(:list, @status, @list)
     end
@@ -49,7 +51,7 @@ class FeedInsertWorker
 
   def perform_push
     case @type
-    when :home
+    when :home, :tags
       FeedManager.instance.push_to_home(@follower, @status, update: update?)
     when :list
       FeedManager.instance.push_to_list(@list, @status, update: update?)
@@ -58,7 +60,7 @@ class FeedInsertWorker
 
   def perform_unpush
     case @type
-    when :home
+    when :home, :tags
       FeedManager.instance.unpush_from_home(@follower, @status, update: true)
     when :list
       FeedManager.instance.unpush_from_list(@list, @status, update: true)
diff --git a/config/routes.rb b/config/routes.rb
index 177c1cff4..7a902b1f0 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -530,6 +530,15 @@ Rails.application.routes.draw do
         resource :note, only: :create, controller: 'accounts/notes'
       end
 
+      resources :tags, only: [:show], constraints: { id: /#{Tag::HASHTAG_NAME_RE}/ } do
+        member do
+          post :follow
+          post :unfollow
+        end
+      end
+
+      resources :followed_tags, only: [:index]
+
       resources :lists, only: [:index, :create, :show, :update, :destroy] do
         resource :accounts, only: [:show, :create, :destroy], controller: 'lists/accounts'
       end
diff --git a/db/migrate/20220714171049_create_tag_follows.rb b/db/migrate/20220714171049_create_tag_follows.rb
new file mode 100644
index 000000000..a393e90f5
--- /dev/null
+++ b/db/migrate/20220714171049_create_tag_follows.rb
@@ -0,0 +1,12 @@
+class CreateTagFollows < ActiveRecord::Migration[6.1]
+  def change
+    create_table :tag_follows do |t|
+      t.belongs_to :tag, null: false, foreign_key: { on_delete: :cascade }
+      t.belongs_to :account, null: false, foreign_key: { on_delete: :cascade }, index: false
+
+      t.timestamps
+    end
+
+    add_index :tag_follows, [:account_id, :tag_id], unique: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 9b465b674..2263dc7d7 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2022_07_10_102457) do
+ActiveRecord::Schema.define(version: 2022_07_14_171049) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -928,6 +928,15 @@ ActiveRecord::Schema.define(version: 2022_07_10_102457) do
     t.datetime "updated_at", null: false
   end
 
+  create_table "tag_follows", force: :cascade do |t|
+    t.bigint "tag_id", null: false
+    t.bigint "account_id", null: false
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["account_id", "tag_id"], name: "index_tag_follows_on_account_id_and_tag_id", unique: true
+    t.index ["tag_id"], name: "index_tag_follows_on_tag_id"
+  end
+
   create_table "tags", force: :cascade do |t|
     t.string "name", default: "", null: false
     t.datetime "created_at", null: false
@@ -1167,6 +1176,8 @@ ActiveRecord::Schema.define(version: 2022_07_10_102457) do
   add_foreign_key "statuses", "statuses", column: "reblog_of_id", on_delete: :cascade
   add_foreign_key "statuses_tags", "statuses", on_delete: :cascade
   add_foreign_key "statuses_tags", "tags", name: "fk_3081861e21", on_delete: :cascade
+  add_foreign_key "tag_follows", "accounts", on_delete: :cascade
+  add_foreign_key "tag_follows", "tags", on_delete: :cascade
   add_foreign_key "tombstones", "accounts", on_delete: :cascade
   add_foreign_key "user_invite_requests", "users", on_delete: :cascade
   add_foreign_key "users", "accounts", name: "fk_50500f500d", on_delete: :cascade
diff --git a/spec/controllers/api/v1/followed_tags_controller_spec.rb b/spec/controllers/api/v1/followed_tags_controller_spec.rb
new file mode 100644
index 000000000..2191350ef
--- /dev/null
+++ b/spec/controllers/api/v1/followed_tags_controller_spec.rb
@@ -0,0 +1,23 @@
+require 'rails_helper'
+
+RSpec.describe Api::V1::FollowedTagsController, type: :controller do
+  render_views
+
+  let(:user)   { Fabricate(:user) }
+  let(:scopes) { 'read:follows' }
+  let(:token)  { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: scopes) }
+
+  before { allow(controller).to receive(:doorkeeper_token) { token } }
+
+  describe 'GET #index' do
+    let!(:tag_follows) { Fabricate.times(5, :tag_follow, account: user.account) }
+
+    before do
+      get :index, params: { limit: 1 }
+    end
+
+    it 'returns http success' do
+      expect(response).to have_http_status(:success)
+    end
+  end
+end
diff --git a/spec/controllers/api/v1/tags_controller_spec.rb b/spec/controllers/api/v1/tags_controller_spec.rb
new file mode 100644
index 000000000..ac42660df
--- /dev/null
+++ b/spec/controllers/api/v1/tags_controller_spec.rb
@@ -0,0 +1,82 @@
+require 'rails_helper'
+
+RSpec.describe Api::V1::TagsController, type: :controller do
+  render_views
+
+  let(:user)   { Fabricate(:user) }
+  let(:scopes) { 'write:follows' }
+  let(:token)  { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: scopes) }
+
+  before { allow(controller).to receive(:doorkeeper_token) { token } }
+
+  describe 'GET #show' do
+    before do
+      get :show, params: { id: name }
+    end
+
+    context 'with existing tag' do
+      let!(:tag) { Fabricate(:tag) }
+      let(:name) { tag.name }
+
+      it 'returns http success' do
+        expect(response).to have_http_status(:success)
+      end
+    end
+
+    context 'with non-existing tag' do
+      let(:name) { 'hoge' }
+
+      it 'returns http success' do
+        expect(response).to have_http_status(:success)
+      end
+    end
+  end
+
+  describe 'POST #follow' do
+    before do
+      post :follow, params: { id: name }
+    end
+
+    context 'with existing tag' do
+      let!(:tag) { Fabricate(:tag) }
+      let(:name) { tag.name }
+
+      it 'returns http success' do
+        expect(response).to have_http_status(:success)
+      end
+
+      it 'creates follow' do
+        expect(TagFollow.where(tag: tag, account: user.account).exists?).to be true
+      end
+    end
+
+    context 'with non-existing tag' do
+      let(:name) { 'hoge' }
+
+      it 'returns http success' do
+        expect(response).to have_http_status(:success)
+      end
+
+      it 'creates follow' do
+        expect(TagFollow.where(tag: Tag.find_by!(name: name), account: user.account).exists?).to be true
+      end
+    end
+  end
+
+  describe 'POST #unfollow' do
+    let!(:tag) { Fabricate(:tag, name: 'foo') }
+    let!(:tag_follow) { Fabricate(:tag_follow, account: user.account, tag: tag) }
+
+    before do
+      post :unfollow, params: { id: tag.name }
+    end
+
+    it 'returns http success' do
+      expect(response).to have_http_status(:success)
+    end
+
+    it 'removes the follow' do
+      expect(TagFollow.where(tag: tag, account: user.account).exists?).to be false
+    end
+  end
+end
diff --git a/spec/fabricators/tag_follow_fabricator.rb b/spec/fabricators/tag_follow_fabricator.rb
new file mode 100644
index 000000000..a2cccb07a
--- /dev/null
+++ b/spec/fabricators/tag_follow_fabricator.rb
@@ -0,0 +1,4 @@
+Fabricator(:tag_follow) do
+  tag
+  account
+end
diff --git a/spec/models/tag_follow_spec.rb b/spec/models/tag_follow_spec.rb
new file mode 100644
index 000000000..50c04d2e4
--- /dev/null
+++ b/spec/models/tag_follow_spec.rb
@@ -0,0 +1,4 @@
+require 'rails_helper'
+
+RSpec.describe TagFollow, type: :model do
+end
-- 
cgit