Update status embeds (#4742)

- Use statuses controller for embeds instead of stream entries controller
- Prefer /@:username/:id/embed URL for embeds
- Use /@:username as author_url in OEmbed
- Add follow link to embeds which opens web intent in new window
- Use redis cache in development
- Cache entire embed

spec/lib/status_finder_spec.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe StatusFinder do
+  include RoutingHelper
+
+  describe '#status' do
+    context 'with a status url' do
+      let(:status) { Fabricate(:status) }
+      let(:url) { short_account_status_url(account_username: status.account.username, id: status.id) }
+      subject { described_class.new(url) }
+
+      it 'finds the stream entry' do
+        expect(subject.status).to eq(status)
+      end
+
+      it 'raises an error if action is not :show' do
+        recognized = Rails.application.routes.recognize_path(url)
+        expect(recognized).to receive(:[]).with(:action).and_return(:create)
+        expect(Rails.application.routes).to receive(:recognize_path).with(url).and_return(recognized)
+
+        expect { subject.status }.to raise_error(ActiveRecord::RecordNotFound)
+      end
+    end
+
+    context 'with a stream entry url' do
+      let(:stream_entry) { Fabricate(:stream_entry) }
+      let(:url) { account_stream_entry_url(stream_entry.account, stream_entry) }
+      subject { described_class.new(url) }
+
+      it 'finds the stream entry' do
+        expect(subject.status).to eq(stream_entry.status)
+      end
+    end
+
+    context 'with a plausible url' do
+      let(:url) { 'https://example.com/users/test/updates/123/embed' }
+      subject { described_class.new(url) }
+
+      it 'raises an error' do
+        expect { subject.status }.to raise_error(ActiveRecord::RecordNotFound)
+      end
+    end
+
+    context 'with an unrecognized url' do
+      let(:url) { 'https://example.com/about' }
+      subject { described_class.new(url) }
+
+      it 'raises an error' do
+        expect { subject.status }.to raise_error(ActiveRecord::RecordNotFound)
+      end
+    end
+  end
+end