ActivityPub: Add basic, read-only support for Outboxes, Notes, and Create/Announce Activities (#2197)

* Clean up collapsible components

* Expose user Outboxes and AS2 representations of statuses

* Save work thus far.

* Fix bad merge.

* Save my work

* Clean up pagination.

* First test working.

* Add tests.

* Add Forbidden error template.

* Revert yarn.lock changes.

* Fix code style deviations and use localized instead of hardcoded English text.

spec/controllers/api/activitypub/outbox_controller_spec.rb

@@ -0,0 +1,92 @@
+require 'rails_helper'
+
+RSpec.describe Api::Activitypub::OutboxController, type: :controller do
+  render_views
+
+  let(:user)  { Fabricate(:user, account: Fabricate(:account, username: 'alice')) }
+
+  describe 'GET #show' do
+    before do
+      @request.env['HTTP_ACCEPT'] = 'application/activity+json'
+    end
+
+    describe 'small number of statuses' do
+      public_status = nil
+
+      before do
+        public_status = Status.create!(account: user.account, text: 'Hello world', visibility: :public)
+        Status.create!(account: user.account, text: 'Hello world', visibility: :private)
+        Status.create!(account: user.account, text: 'Hello world', visibility: :unlisted)
+        Status.create!(account: user.account, text: 'Hello world', visibility: :direct)
+
+        get :show, id: user.account.id
+      end
+
+      it 'returns http success' do
+        expect(response).to have_http_status(:success)
+      end
+
+      it 'sets Content-Type header to AS2' do
+        expect(response.header['Content-Type']).to include 'application/activity+json'
+      end
+
+      it 'sets Access-Control-Allow-Origin header to *' do
+        expect(response.header['Access-Control-Allow-Origin']).to eq '*'
+      end
+
+      it 'returns AS2 JSON body' do
+        json_data = JSON.parse(response.body)
+        expect(json_data).to include('@context' => 'https://www.w3.org/ns/activitystreams')
+        expect(json_data).to include('id' => @request.url)
+        expect(json_data).to include('type' => 'OrderedCollection')
+        expect(json_data).to include('totalItems' => 1)
+        expect(json_data).to include('items')
+        expect(json_data['items'].count).to eq(1)
+        expect(json_data['items']).to include(api_activitypub_status_url(public_status))
+      end
+    end
+
+    describe 'large number of statuses' do
+      before do
+        30.times do
+          Status.create!(account: user.account, text: 'Hello world', visibility: :public)
+        end
+
+        Status.create!(account: user.account, text: 'Hello world', visibility: :private)
+        Status.create!(account: user.account, text: 'Hello world', visibility: :unlisted)
+        Status.create!(account: user.account, text: 'Hello world', visibility: :direct)
+      end
+
+      describe 'first page' do
+        before do
+          get :show, id: user.account.id
+        end
+
+        it 'returns http success' do
+          expect(response).to have_http_status(:success)
+        end
+
+        it 'sets Content-Type header to AS2' do
+          expect(response.header['Content-Type']).to include 'application/activity+json'
+        end
+
+        it 'sets Access-Control-Allow-Origin header to *' do
+          expect(response.header['Access-Control-Allow-Origin']).to eq '*'
+        end
+
+        it 'returns AS2 JSON body' do
+          json_data = JSON.parse(response.body)
+          expect(json_data).to include('@context' => 'https://www.w3.org/ns/activitystreams')
+          expect(json_data).to include('id' => @request.url)
+          expect(json_data).to include('type' => 'OrderedCollectionPage')
+          expect(json_data).to include('totalItems' => 20)
+          expect(json_data).to include('items')
+          expect(json_data['items'].count).to eq(20)
+          expect(json_data).to include('current' => @request.url)
+          expect(json_data).to include('next')
+          expect(json_data).to_not include('prev')
+        end
+      end
+    end
+  end
+end