Remove sign-in token authentication, instead send e-mail about new sign-in (#17970)

spec/lib/suspicious_sign_in_detector_spec.rb

@@ -0,0 +1,57 @@
+require 'rails_helper'
+
+RSpec.describe SuspiciousSignInDetector do
+  describe '#suspicious?' do
+    let(:user) { Fabricate(:user, current_sign_in_at: 1.day.ago) }
+    let(:request) { double(remote_ip: remote_ip) }
+    let(:remote_ip) { nil }
+
+    subject { described_class.new(user).suspicious?(request) }
+
+    context 'when user has 2FA enabled' do
+      before do
+        user.update!(otp_required_for_login: true)
+      end
+
+      it 'returns false' do
+        expect(subject).to be false
+      end
+    end
+
+    context 'when exact IP has been used before' do
+      let(:remote_ip) { '1.1.1.1' }
+
+      before do
+        user.update!(sign_up_ip: remote_ip)
+      end
+
+      it 'returns false' do
+        expect(subject).to be false
+      end
+    end
+
+    context 'when similar IP has been used before' do
+      let(:remote_ip) { '1.1.2.2' }
+
+      before do
+        user.update!(sign_up_ip: '1.1.1.1')
+      end
+
+      it 'returns false' do
+        expect(subject).to be false
+      end
+    end
+
+    context 'when IP is completely unfamiliar' do
+      let(:remote_ip) { '2.2.2.2' }
+
+      before do
+        user.update!(sign_up_ip: '1.1.1.1')
+      end
+
+      it 'returns true' do
+        expect(subject).to be true
+      end
+    end
+  end
+end