Change unapproved and unconfirmed account to not be accessible in the REST API (#17530)

* Change unapproved and unconfirmed account to not be accessible in the REST API

* Change Account#searchable? to reject unconfirmed and unapproved users

* Disable search for unapproved and unconfirmed users in Account.search_for

* Disable search for unapproved and unconfirmed users in Account.advanced_search_for

* Remove unconfirmed and unapproved accounts from Account.searchable scope

* Prevent mentions to unapproved/unconfirmed accounts

* Fix some old tests for Account.advanced_search_for

* Add some Account.advanced_search_for tests for existing behaviors

* Add some tests for Account.search_for

* Add Account.advanced_search_for tests unconfirmed and unapproved accounts

* Add Account.searchable tests

* Fix Account.without_unapproved scope potentially messing with previously-applied scopes

* Allow lookup of unconfirmed/unapproved accounts through /api/v1/accounts/lookup

This is so that the API can still be used to check whether an username is free
to use.

4 files changed, 194 insertions, 6 deletions

diff --git a/app/controllers/api/v1/accounts_controller.rb b/app/controllers/api/v1/accounts_controller.rb
index 5134bfb94a6..5537cc9b0bd 100644
--- a/app/controllers/api/v1/accounts_controller.rb
+++ b/app/controllers/api/v1/accounts_controller.rb
@@ -9,6 +9,8 @@ class Api::V1::AccountsController < Api::BaseController
 
   before_action :require_user!, except: [:show, :create]
   before_action :set_account, except: [:create]
+  before_action :check_account_approval, except: [:create]
+  before_action :check_account_confirmation, except: [:create]
   before_action :check_enabled_registrations, only: [:create]
 
   skip_before_action :require_authenticated_user!, only: :create
@@ -74,6 +76,14 @@ class Api::V1::AccountsController < Api::BaseController
     @account = Account.find(params[:id])
   end
 
+  def check_account_approval
+    raise(ActiveRecord::RecordNotFound) if @account.local? && @account.user_pending?
+  end
+
+  def check_account_confirmation
+    raise(ActiveRecord::RecordNotFound) if @account.local? && !@account.user_confirmed?
+  end
+
   def relationships(**options)
     AccountRelationshipsPresenter.new([@account.id], current_user.account_id, **options)
   end
diff --git a/app/models/account.rb b/app/models/account.rb
index 7b460b05474..bd94142c430 100644
--- a/app/models/account.rb
+++ b/app/models/account.rb
@@ -109,7 +109,8 @@ class Account < ApplicationRecord
   scope :matches_username, ->(value) { where(arel_table[:username].matches("#{value}%")) }
   scope :matches_display_name, ->(value) { where(arel_table[:display_name].matches("#{value}%")) }
   scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
-  scope :searchable, -> { without_suspended.where(moved_to_account_id: nil) }
+  scope :without_unapproved, -> { left_outer_joins(:user).remote.or(left_outer_joins(:user).merge(User.approved.confirmed)) }
+  scope :searchable, -> { without_unapproved.without_suspended.where(moved_to_account_id: nil) }
   scope :discoverable, -> { searchable.without_silenced.where(discoverable: true).left_outer_joins(:account_stat) }
   scope :followable_by, ->(account) { joins(arel_table.join(Follow.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:id].eq(Follow.arel_table[:target_account_id]).and(Follow.arel_table[:account_id].eq(account.id))).join_sources).where(Follow.arel_table[:id].eq(nil)).joins(arel_table.join(FollowRequest.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:id].eq(FollowRequest.arel_table[:target_account_id]).and(FollowRequest.arel_table[:account_id].eq(account.id))).join_sources).where(FollowRequest.arel_table[:id].eq(nil)) }
   scope :by_recent_status, -> { order(Arel.sql('(case when account_stats.last_status_at is null then 1 else 0 end) asc, account_stats.last_status_at desc, accounts.id desc')) }
@@ -193,7 +194,7 @@ class Account < ApplicationRecord
   end
 
   def searchable?
-    !(suspended? || moved?)
+    !(suspended? || moved?) && (!local? || (approved? && confirmed?))
   end
 
   def possibly_stale?
@@ -461,9 +462,11 @@ class Account < ApplicationRecord
           accounts.*,
           ts_rank_cd(#{TEXTSEARCH}, to_tsquery('simple', :tsquery), 32) AS rank
         FROM accounts
+        LEFT JOIN users ON accounts.id = users.account_id
         WHERE to_tsquery('simple', :tsquery) @@ #{TEXTSEARCH}
           AND accounts.suspended_at IS NULL
           AND accounts.moved_to_account_id IS NULL
+          AND (accounts.domain IS NOT NULL OR (users.approved = TRUE AND users.confirmed_at IS NOT NULL))
         ORDER BY rank DESC
         LIMIT :limit OFFSET :offset
       SQL
@@ -539,9 +542,11 @@ class Account < ApplicationRecord
             (count(f.id) + 1) * ts_rank_cd(#{TEXTSEARCH}, to_tsquery('simple', :tsquery), 32) AS rank
           FROM accounts
           LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = :id) OR (accounts.id = f.target_account_id AND f.account_id = :id)
+          LEFT JOIN users ON accounts.id = users.account_id
           WHERE to_tsquery('simple', :tsquery) @@ #{TEXTSEARCH}
             AND accounts.suspended_at IS NULL
             AND accounts.moved_to_account_id IS NULL
+            AND (accounts.domain IS NOT NULL OR (users.approved = TRUE AND users.confirmed_at IS NOT NULL))
           GROUP BY accounts.id
           ORDER BY rank DESC
           LIMIT :limit OFFSET :offset
diff --git a/app/services/process_mentions_service.rb b/app/services/process_mentions_service.rb
index 9d239fc6570..8c63b611d36 100644
--- a/app/services/process_mentions_service.rb
+++ b/app/services/process_mentions_service.rb
@@ -37,6 +37,9 @@ class ProcessMentionsService < BaseService
 
       mentioned_account = Account.find_remote(username, domain)
 
+      # Unapproved and unconfirmed accounts should not be mentionable
+      next if mentioned_account&.local? && !(mentioned_account.user_confirmed? && mentioned_account.user_approved?)
+
       # If the account cannot be found or isn't the right protocol,
       # first try to resolve it
       if mention_undeliverable?(mentioned_account)
diff --git a/spec/models/account_spec.rb b/spec/models/account_spec.rb
index 681134d498a..dc0ca3da374 100644
--- a/spec/models/account_spec.rb
+++ b/spec/models/account_spec.rb
@@ -350,6 +350,45 @@ RSpec.describe Account, type: :model do
       )
     end
 
+    it 'does not return suspended users' do
+      match = Fabricate(
+        :account,
+        display_name: 'Display Name',
+        username: 'username',
+        domain: 'example.com',
+        suspended: true
+      )
+
+      results = Account.search_for('username')
+      expect(results).to eq []
+    end
+
+    it 'does not return unapproved users' do
+      match = Fabricate(
+        :account,
+        display_name: 'Display Name',
+        username: 'username'
+      )
+
+      match.user.update(approved: false)
+
+      results = Account.search_for('username')
+      expect(results).to eq []
+    end
+
+    it 'does not return unconfirmed users' do
+      match = Fabricate(
+        :account,
+        display_name: 'Display Name',
+        username: 'username'
+      )
+
+      match.user.update(confirmed_at: nil)
+
+      results = Account.search_for('username')
+      expect(results).to eq []
+    end
+
     it 'accepts ?, \, : and space as delimiter' do
       match = Fabricate(
         :account,
@@ -422,8 +461,114 @@ RSpec.describe Account, type: :model do
   end
 
   describe '.advanced_search_for' do
+    let(:account) { Fabricate(:account) }
+
+    context 'when limiting search to followed accounts' do
+      it 'accepts ?, \, : and space as delimiter' do
+        match = Fabricate(
+          :account,
+          display_name: 'A & l & i & c & e',
+          username: 'username',
+          domain: 'example.com'
+        )
+        account.follow!(match)
+
+        results = Account.advanced_search_for('A?l\i:c e', account, 10, true)
+        expect(results).to eq [match]
+      end
+
+      it 'does not return non-followed accounts' do
+        match = Fabricate(
+          :account,
+          display_name: 'A & l & i & c & e',
+          username: 'username',
+          domain: 'example.com'
+        )
+
+        results = Account.advanced_search_for('A?l\i:c e', account, 10, true)
+        expect(results).to eq []
+      end
+
+      it 'does not return suspended users' do
+        match = Fabricate(
+          :account,
+          display_name: 'Display Name',
+          username: 'username',
+          domain: 'example.com',
+          suspended: true
+        )
+
+        results = Account.advanced_search_for('username', account, 10, true)
+        expect(results).to eq []
+      end
+
+      it 'does not return unapproved users' do
+        match = Fabricate(
+          :account,
+          display_name: 'Display Name',
+          username: 'username'
+        )
+
+        match.user.update(approved: false)
+
+        results = Account.advanced_search_for('username', account, 10, true)
+        expect(results).to eq []
+      end
+
+      it 'does not return unconfirmed users' do
+        match = Fabricate(
+          :account,
+          display_name: 'Display Name',
+          username: 'username'
+        )
+
+        match.user.update(confirmed_at: nil)
+
+        results = Account.advanced_search_for('username', account, 10, true)
+        expect(results).to eq []
+      end
+    end
+
+    it 'does not return suspended users' do
+      match = Fabricate(
+        :account,
+        display_name: 'Display Name',
+        username: 'username',
+        domain: 'example.com',
+        suspended: true
+      )
+
+      results = Account.advanced_search_for('username', account)
+      expect(results).to eq []
+    end
+
+    it 'does not return unapproved users' do
+      match = Fabricate(
+        :account,
+        display_name: 'Display Name',
+        username: 'username'
+      )
+
+      match.user.update(approved: false)
+
+      results = Account.advanced_search_for('username', account)
+      expect(results).to eq []
+    end
+
+    it 'does not return unconfirmed users' do
+      match = Fabricate(
+        :account,
+        display_name: 'Display Name',
+        username: 'username'
+      )
+
+      match.user.update(confirmed_at: nil)
+
+      results = Account.advanced_search_for('username', account)
+      expect(results).to eq []
+    end
+
     it 'accepts ?, \, : and space as delimiter' do
-      account = Fabricate(:account)
       match = Fabricate(
         :account,
         display_name: 'A & l & i & c & e',
@@ -437,18 +582,17 @@ RSpec.describe Account, type: :model do
 
     it 'limits by 10 by default' do
       11.times { Fabricate(:account, display_name: "Display Name") }
-      results = Account.search_for("display")
+      results = Account.advanced_search_for("display", account)
       expect(results.size).to eq 10
     end
 
     it 'accepts arbitrary limits' do
       2.times { Fabricate(:account, display_name: "Display Name") }
-      results = Account.search_for("display", 1)
+      results = Account.advanced_search_for("display", account, 1)
       expect(results.size).to eq 1
     end
 
     it 'ranks followed accounts higher' do
-      account = Fabricate(:account)
       match = Fabricate(:account, username: "Matching")
       followed_match = Fabricate(:account, username: "Matcher")
       Fabricate(:follow, account: account, target_account: followed_match)
@@ -775,6 +919,32 @@ RSpec.describe Account, type: :model do
         expect(Account.suspended).to match_array([account_1])
       end
     end
+
+    describe 'searchable' do
+      let!(:suspended_local)        { Fabricate(:account, suspended: true, username: 'suspended_local') }
+      let!(:suspended_remote)       { Fabricate(:account, suspended: true, domain: 'example.org', username: 'suspended_remote') }
+      let!(:silenced_local)         { Fabricate(:account, silenced: true, username: 'silenced_local') }
+      let!(:silenced_remote)        { Fabricate(:account, silenced: true, domain: 'example.org', username: 'silenced_remote') }
+      let!(:unconfirmed)            { Fabricate(:user, confirmed_at: nil).account }
+      let!(:unapproved)             { Fabricate(:user, approved: false).account }
+      let!(:unconfirmed_unapproved) { Fabricate(:user, confirmed_at: nil, approved: false).account }
+      let!(:local_account)          { Fabricate(:account, username: 'local_account') }
+      let!(:remote_account)         { Fabricate(:account, domain: 'example.org', username: 'remote_account') }
+
+      before do
+        # Accounts get automatically-approved depending on settings, so ensure they aren't approved
+        unapproved.user.update(approved: false)
+        unconfirmed_unapproved.user.update(approved: false)
+      end
+
+      it 'returns every usable non-suspended account' do
+        expect(Account.searchable).to match_array([silenced_local, silenced_remote, local_account, remote_account])
+      end
+
+      it 'does not mess with previously-applied scopes' do
+        expect(Account.where.not(id: remote_account.id).searchable).to match_array([silenced_local, silenced_remote, local_account])
+      end
+    end
   end
 
   context 'when is local' do