What does "mock" mean in programming?

mock is one of the most common terms in software development. This guide explains what it means, how it is used in practice, and why it matters, with real examples from the developer world.

Definition

A fake object used in tests to replace a real dependency. Mocks let you test a component in isolation, control what the dependency returns, and verify how the component interacts with it.

Example

"Mock the external API so the test passes without making a real network call."

Word forms

Form	Type	Meaning	Example
mock	noun	A fake object used in tests to replace a real dependency	"Use a mock for the email service so tests do not send real emails."
mock	verb (infinitive)	To replace a real dependency with a fake one in tests	"Mock the payment API to avoid charging real cards during testing."
mocked	past tense	Already replaced with a fake object for testing	"The database calls are mocked so the test runs without a real database."
mocking	gerund	The act of replacing real dependencies with fakes in tests	"Mocking external services keeps unit tests fast and predictable."

Related terms

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