layout	title	folder	permalink	categories	tags
pattern	Arrange/Act/Assert	arrange-act-assert	/patterns/arrange-act-assert/	Idiom	Testing

Also known as

Given/When/Then

Intent

The Arrange/Act/Assert (AAA) is a pattern for organizing unit tests. It breaks tests down into three clear and distinct steps:

1. Arrange: Perform the setup and initialization required for the test.
2. Act: Take action(s) required for the test.
3. Assert: Verify the outcome(s) of the test.

Applicability

Use Arrange/Act/Assert pattern when

• you need to structure your unit tests so they're easier to read, maintain, and enhance.

Credits

• Arrange, Act, Assert: What is AAA Testing?
• Bill Wake: 3A – Arrange, Act, Assert
• Martin Fowler: GivenWhenThen