Test Service Task

Problem

A Rails team needs help with a task in this area:

Use when writing RSpec tests for service objects in spec/services/ — write spec FIRST and verify it fails for the right reason, use subject(:service_call) { described_class.call(params) } with describe '.call', test the public contract not internal implementation, use instance_double for isolation and create for integration, cover happy path + error/edge cases + blank/invalid input, use aggregate_failures for multi-assertion tests, change matchers for state verification, travel_to for time-dependent logic, FactoryBot hash factories (class: Hash with initialize_with) for API responses.

The team has asked for a concise implementation artifact that a reviewer can inspect without needing to observe the agent's process.

Output

Create answer.md with:

• a short plan for the work
• the concrete Rails-oriented artifact or recommendation
• the verification steps or quality gates that should be run
• any assumptions that affect the result