Factory Bot for RSpec FAQs

Question 1

Can Factory Bot handle has_many associations?

Accepted Answer

Yes, Factory Bot handles has_many associations using transient attributes combined with after(:create) callbacks to generate a specific number of child records automatically.

Question 2

How does build_stubbed improve test performance?

Accepted Answer

build_stubbed is the fastest strategy because it creates a mock object with a fake ID and stubbed associations without ever touching the database, significantly reducing execution time for isolated tests.

Question 3

How do sequences help in Factory Bot?

Accepted Answer

Sequences generate unique values for attributes like emails or usernames by incrementing a counter, preventing database uniqueness validation errors during test runs.

Question 4

When should I use 'build' vs 'create' in Factory Bot?

Accepted Answer

Use 'build' when you only need an in-memory object for unit tests or validations. Use 'create' when your test requires the object to be persisted in the database, which is common in integration or system tests.

Question 5

What are the benefits of using traits?

Accepted Answer

Traits allow you to define specific sets of attributes or states—like :admin, :active, or :with_posts—that can be mixed into any factory call, reducing code duplication and improving test readability.

Factory Bot for RSpec

Key Features

Use Cases

Factory Bot for RSpec

Key Features

Use Cases