The AI Playwright Test Planner Agent: Transforming User Stories into Testable Invariants

01. The Problem

02. The Concrete Engineering Scenario

A fintech team delivers an updated 'Instant Cross-Border Transfer' feature with live foreign exchange rate quotes, dynamic fees, and KYC tier limits. The SDET needs an exhaustive test plan covering happy paths, negative validations, currency roundoff limits, and state assertions.

03. Context & Inputs Provided to Agent

• •Feature User Story: 'As an authenticated user, I can transfer EUR to USD with live locked rate for 60 seconds.'
• •OpenAPI Specification for POST /api/v1/transfers and GET /api/v1/exchange-rates.
• •PostgreSQL schema for wallets (balance numeric(18,4)) and transactions (status enum).

04. Agent Reasoning & Planning Steps

// Generated Blueprint from AI Test Planner Agent
import { test, expect } from '@playwright/test';

test.describe('Feature: Instant Transfer - State Invariant Verification', () => {
  // Invariant 1: Source wallet balance deduction must exactly equal sendAmount + fee
  test('Transfer initiation strictly debits source wallet including flat fee', async ({ request }) => {
    test.info().annotations.push({ type: 'invariant', description: 'sourceBalance(t1) === sourceBalance(t0) - (amount + 25)' });
    // Test implementation generated downstream
  });

  // Invariant 2: Expired quote token must be rejected before debit occurs
  test('Expired quote token (age > 60s) returns HTTP 410 Gone without altering wallet balance', async ({ request }) => {
    // Assert 410 status and verify DB balance unmodified
  });
});