Test Data Builder Generator

Generates Test Data Builder and Object Mother patterns for test data creation.

Patterns

Test Data Builder

Fluent interface for constructing test objects with customizable properties.

When to use:

• Complex objects with many properties
• Need to customize specific properties per test
• Want to express test intent clearly

Object Mother

Factory methods returning pre-configured objects for common scenarios.

When to use:

• Standard test fixtures (default user, pending order)
• Shared across many tests
• Named scenarios (premium customer, expired subscription)

References

• references/templates.md — Builder and Object Mother class templates
• references/examples.md — Complete Order example with Value Object builders and usage

Generation Instructions

1. Analyze the target class:

   • Constructor parameters
   • Required vs optional properties
   • Value objects used
   • State transitions (for entities)

2. Determine sensible defaults:

   • Generate IDs automatically
   • Use common/valid values
   • Consider relationships

3. Create Builder with:

   • Private constructor with defaults
   • Static factory method (aOrder, anEmail)
   • with* methods for each property
   • Immutable (clone in each method)
   • build() method

4. Create Mother with:

   • default() method
   • Named scenarios (pending, confirmed, premium)
   • Parameterized methods (forCustomer, withTotal)

5. File placement:

   • Builders: tests/Builder/{ClassName}Builder.php
   • Mothers: tests/Mother/{ClassName}Mother.php

Best Practices

1. Sensible defaults — Tests should work without customization
2. Fluent interface — Chain method calls
3. Immutable builders — Clone in each with* method
4. Expressive names — pending() not withStatus(pending)
5. Composition — Builders can use other Mothers/Builders
6. Single Responsibility — One builder per aggregate/entity