Chapter 6 – Test Tools
Test Double – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
A generic term for any object that stands in for a real dependency in a test — includes dummies, stubs, spies, mocks, and fakes.
In simple words
Any stand-in object used in place of a real dependency.
Exam tip
Meszaros’ five test doubles — dummy, stub, spy, mock, fake — appear in most senior interview loops.
Related terms
- StubFake code you drop in for a not-yet-built dependency so your module can be tested.
- Mock ObjectA fake dependency you configure to expect specific calls and assert on them afterwards.
- FakeA working but simplified stand-in — e.g. an in-memory DB.
- Dummy ObjectAn empty placeholder object used to satisfy a signature.
- SpyA stand-in that records calls made to it for later inspection.
Practice this term in the ISTQB Mock Test
40 CTFL v4.0 questions, 60-minute timer, instant scoring and chapter-wise breakdown.
Practice in Mock Test