Improve test coverage for OtpRequestsTracker

spec/models/otp_requests_tracker_spec.rb

@@ -0,0 +1,51 @@
+require 'rails_helper'
+
+describe OtpRequestsTracker do
+  describe '.find_or_create_with_phone' do
+    let(:phone) { '+1 703 555 1212' }
+    let(:phone_fingerprint) { Pii::Fingerprinter.fingerprint(phone) }
+
+    context 'match found' do
+      it 'returns the existing record and does not change it' do
+        OtpRequestsTracker.create(
+          phone_fingerprint: phone_fingerprint,
+          otp_send_count: 3,
+          otp_last_sent_at: Time.zone.now - 1.hour
+        )
+
+        existing = OtpRequestsTracker.where(phone_fingerprint: phone_fingerprint).first
+
+        expect { OtpRequestsTracker.find_or_create_with_phone(phone) }.
+          to_not change(OtpRequestsTracker, :count)
+        expect { OtpRequestsTracker.find_or_create_with_phone(phone) }.
+          to_not change { existing.otp_send_count }
+        expect { OtpRequestsTracker.find_or_create_with_phone(phone) }.
+          to_not change { existing.otp_last_sent_at }
+      end
+    end
+
+    context 'match not found' do
+      it 'creates new record with otp_send_count = 0 and otp_last_sent_at = current time' do
+        expect { OtpRequestsTracker.find_or_create_with_phone(phone) }.
+          to change(OtpRequestsTracker, :count).by(1)
+
+        existing = OtpRequestsTracker.where(phone_fingerprint: phone_fingerprint).first
+
+        expect(existing.otp_send_count).to eq 0
+        expect(existing.otp_last_sent_at).to be_within(2.seconds).of(Time.zone.now)
+      end
+    end
+
+    context 'race condition' do
+      it 'retries once, then raises ActiveRecord::RecordNotUnique' do
+        tracker = OtpRequestsTracker.new
+        allow(OtpRequestsTracker).to receive(:where).
+          and_raise(ActiveRecord::RecordNotUnique.new(tracker))
+
+        expect(OtpRequestsTracker).to receive(:where).exactly(:once)
+        expect { OtpRequestsTracker.find_or_create_with_phone(phone) }.
+          to raise_error ActiveRecord::RecordNotUnique
+      end
+    end
+  end
+end