test-data-management

Test Data Management

<default_to_action> When creating or managing test data:

1. NEVER use production PII directly
2. GENERATE synthetic data with faker libraries
3. ANONYMIZE production data if used (mask, hash)
4. ISOLATE test data (transactions, per-test cleanup)
5. SCALE with batch generation (10k+ records/sec)

Quick Data Strategy:

• Unit tests: Minimal data (just enough)
• Integration: Realistic data (full complexity)
• Performance: Volume data (10k+ records)

Critical Success Factors:

• 40% of test failures from inadequate data
• GDPR fines up to €20M for PII violations
• Never store production PII in test environments </default_to_action>

Quick Reference Card

When to Use

• Creating test datasets
• Handling sensitive data
• Performance testing with volume
• GDPR/CCPA compliance

Data Strategies

Type	When	Size
Minimal	Unit tests	1-10 records
Realistic	Integration	100-1000 records
Volume	Performance	10k+ records
Edge cases	Boundary testing	Targeted

Privacy Techniques

Technique	Use Case
Synthetic	Generate fake data (preferred)
Masking	j***@example.com
Hashing	Irreversible pseudonymization
Tokenization	Reversible with key

---

Synthetic Data Generation

import { faker } from '@faker-js/faker';

// Seed for reproducibility
faker.seed(123);

function generateUser() {
  return {
    id: faker.string.uuid(),
    email: faker.internet.email(),
    firstName: faker.person.firstName(),
    lastName: faker.person.lastName(),
    phone: faker.phone.number(),
    address: {
      street: faker.location.streetAddress(),
      city: faker.location.city(),
      zip: faker.location.zipCode()
    },
    createdAt: faker.date.past()
  };
}

// Generate 1000 users
const users = Array.from({ length: 1000 }, generateUser);

---

Test Data Builder Pattern

class UserBuilder {
  private user: Partial<User> = {};

  asAdmin() {
    this.user.role = 'admin';
    this.user.permissions = ['read', 'write', 'delete'];
    return this;
  }

  asCustomer() {
    this.user.role = 'customer';
    this.user.permissions = ['read'];
    return this;
  }

  withEmail(email: string) {
    this.user.email = email;
    return this;
  }

  build(): User {
    return {
      id: this.user.id ?? faker.string.uuid(),
      email: this.user.email ?? faker.internet.email(),
      role: this.user.role ?? 'customer',
      ...this.user
    } as User;
  }
}

// Usage
const admin = new UserBuilder().asAdmin().withEmail('[email protected]').build();
const customer = new UserBuilder().asCustomer().build();