Add announcements (#12662)

* Add announcements

Fix #11006

* Add reactions to announcements

* Add admin UI for announcements

* Add unit tests

* Fix issues

- Add `with_dismissed` param to announcements API
- Fix end date not being formatted when time range is given
- Fix announcement delete causing reactions to send streaming updates
- Fix announcements container growing too wide and mascot too small
- Fix `all_day` being settable when no time range is given
- Change text "Update" to "Announcement"

* Fix scheduler unpublishing announcements before they are due

* Fix filter params not being passed to announcements filter

spec/controllers/api/v1/announcements_controller_spec.rb

@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Api::V1::AnnouncementsController, type: :controller do
+  render_views
+
+  let(:user)   { Fabricate(:user) }
+  let(:scopes) { 'read' }
+  let(:token)  { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: scopes) }
+
+  let!(:announcement) { Fabricate(:announcement) }
+
+  describe 'GET #index' do
+    context 'without token' do
+      it 'returns http unprocessable entity' do
+        get :index
+        expect(response).to have_http_status :unprocessable_entity
+      end
+    end
+
+    context 'with token' do
+      before do
+        allow(controller).to receive(:doorkeeper_token) { token }
+        get :index
+      end
+
+      it 'returns http success' do
+        expect(response).to have_http_status(200)
+      end
+    end
+  end
+
+  describe 'POST #dismiss' do
+    context 'without token' do
+      it 'returns http unauthorized' do
+        post :dismiss, params: { id: announcement.id }
+        expect(response).to have_http_status :unauthorized
+      end
+    end
+
+    context 'with token' do
+      let(:scopes) { 'write:accounts' }
+
+      before do
+        allow(controller).to receive(:doorkeeper_token) { token }
+        post :dismiss, params: { id: announcement.id }
+      end
+
+      it 'returns http success' do
+        expect(response).to have_http_status(200)
+      end
+
+      it 'dismisses announcement' do
+        expect(announcement.announcement_mutes.find_by(account: user.account)).to_not be_nil
+      end
+    end
+  end
+end