--- title: "Terminology" url: "https://courses.osherove.com/courses/the-art-of-unit-testing-and-tdd-in-java/terminology.md" canonical: "https://courses.osherove.com/courses/the-art-of-unit-testing-and-tdd-in-java/terminology/" tags: [] author: "Roy Osherove" description: "Lesson 10 of 21 in The Art of Unit Testing and TDD in Java (Day 2), 0:56. Free video by Roy Osherove." usage: "Licensed under CC BY 4.0 — reuse, quote and adapt with attribution (Roy Osherove, link to the original page)." license: "https://creativecommons.org/licenses/by/4.0/" --- # Terminology 1. [Courses](https://courses.osherove.com/#courses) 2. [The Art of Unit Testing and TDD in Java](https://courses.osherove.com/courses/the-art-of-unit-testing-and-tdd-in-java/) 3. Day 2 Lesson 10 of 21 Duration: 0:56 [Watch on YouTube](https://www.youtube.com/watch?v=Bp2_Je2h-To) [Fake](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-5#ch05lev1sec2 "Dynamically creating a fake object (The Art of Unit Testing, 2nd ed., ch. 5)"), [Stub](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-3#ch03lev1sec1 "Introducing stubs (The Art of Unit Testing, 2nd ed., ch. 3)"), [Mock](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-4 "Interaction testing using mock objects (The Art of Unit Testing, 2nd ed., ch. 4)"), Spy... what does it all mean? Let's talk about it. ## In this lesson Roy Osherove contrasts his simple terminology with the book xUnit Test Patterns, which gives many different names to things that look like other things. He only uses [fakes](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-4#ch04lev1sec2 "The difference between mocks and stubs (The Art of Unit Testing, 2nd ed., ch. 4)"): a fake that is asserted on is a [mock](https://livebook.manning.com/book/the-art-of-unit-testing-third-edition/chapter-4#sigil_toc_id_76 "Interaction testing, mocks, and stubs (The Art of Unit Testing, 3rd ed., ch. 4)"), any other fake is a [stub](https://livebook.manning.com/book/the-art-of-unit-testing-third-edition/chapter-3#sigil_toc_id_62 "Reasons to use stubs (The Art of Unit Testing, 3rd ed., ch. 3)"), and terms such as test spy can be learned later. ## Transcript 158 words [\[00:04\]](https://www.youtube.com/watch?v=Bp2_Je2h-To&t=4s) So I hope that makes some sense. Are there any questions so far? Okay. So just to remind you, we have the terminology we're using. Now there are many different terminologies. The the the one on the right is from a book called xUnit Test Patterns. It's a very good book, but the it assumes it gives many different names to all these things that look like other things. And I find that that's very confusing. So I just use a very very simple terminology. I I either have I I have [fakes](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-4#ch04lev1sec2 "The difference between mocks and stubs (The Art of Unit Testing, 2nd ed., ch. 4)") and whether they're being asserted on or not, [\[00:40\]](https://www.youtube.com/watch?v=Bp2_Je2h-To&t=40s) That's the only difference. So if you assert on the fake, it's a [mock](https://osherove.com/blog/2005/6/30/the-mock-objects-elevator-speech.html "The Mock Objects elevator speech (osherove.com)"). Otherwise, it's a [stub](https://livebook.manning.com/book/the-art-of-unit-testing-third-edition/chapter-3#sigil_toc_id_62 "Reasons to use stubs (The Art of Unit Testing, 3rd ed., ch. 3)"). That's the only thing that you should know currently. And you can always learn about the other things like test spy, etc. But for now, if you just think about it like that, it should simplify your life very ## Related - [The importance of differentiating between mocks and stubs](https://livebook.manning.com/book/the-art-of-unit-testing-third-edition/chapter-4#sigil_toc_id_79) · The Art of Unit Testing, 3rd ed., ch. 4 The 3rd edition's section on why to differentiate between mocks and stubs, the distinction this lesson keeps simple. - [Mocks and Stubs - The difference is in the flow of information](https://osherove.com/blog/2007/9/16/mocks-and-stubs-the-difference-is-in-the-flow-of-information.html) · osherove.com Roy's short explanation that mocks and stubs differ in the flow of information, a quick take on the same terms. - [Goodbye mocks, Farewell stubs](https://osherove.com/blog/2008/9/20/goodbye-mocks-farewell-stubs.html) · osherove.com Roy's post on fakes, mocks and stubs from his consulting, related to his choice to just say 'fake'. ### Also linked in this lesson #### The Art of Unit Testing, 3rd ed. - [Interaction testing, mocks, and stubs](https://livebook.manning.com/book/the-art-of-unit-testing-third-edition/chapter-4#sigil_toc_id_76), ch. 4 - [Reasons to use stubs](https://livebook.manning.com/book/the-art-of-unit-testing-third-edition/chapter-3#sigil_toc_id_62), ch. 3 #### The Art of Unit Testing, 2nd ed. - [The difference between mocks and stubs](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-4#ch04lev1sec2), ch. 4 - [Dynamically creating a fake object](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-5#ch05lev1sec2), ch. 5 - [Introducing stubs](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-3#ch03lev1sec1), ch. 3 - [Interaction testing using mock objects](https://livebook.manning.com/book/the-art-of-unit-testing-second-edition/chapter-4), ch. 4 #### osherove.com - [The Mock Objects elevator speech](https://osherove.com/blog/2005/6/30/the-mock-objects-elevator-speech.html) [Previous lesson Demo - Mock Objects](https://courses.osherove.com/courses/the-art-of-unit-testing-and-tdd-in-java/demo-mock-objects/) [Next lesson Mocks And Stubs](https://courses.osherove.com/courses/the-art-of-unit-testing-and-tdd-in-java/mocks-and-stubs/) --- ## About the author **Roy Osherove**: Senior Solutions Architect at AWS working on AI for production and AI-driven development; author of The Art of Unit Testing and Elastic Leadership, with about 20 years of consulting and training on unit testing, TDD, team leadership and continuous delivery. ### Sites - [RobotPaper](https://robotpaper.ai/): This blog: AI patterns and anti-patterns, AI and coding agents, and engineering leadership. - [osherove.com](https://osherove.com): Roy's personal site. Author of The Art of Unit Testing and Elastic Leadership; consulting and training on unit testing, TDD, team leadership and continuous delivery, plus about 20 years of blog posts. - [The Art of Unit Testing](https://www.artofunittesting.com): The Art of Unit Testing, 3rd Edition (Manning): readable, maintainable, trustworthy unit tests, plus TDD workshops in C#, JavaScript, Java and Kotlin. - [5whys.com](https://www.5whys.com): Roy's writing on software team leadership: self-organizing teams, surviving chaos, learning mode and the Elastic Leadership model. - [Pipeline Driven](https://pipelinedriven.org): Continuous delivery and DevOps practices: build patterns, pipeline-friendly testing, DevOps metrics and enterprise DevOps. - [Elastic Leadership](https://www.elasticleadership.com): Elastic Leadership, Roy's framework for software team leaders (survival, learning and self-organizing modes). ### Social - X: https://x.com/royosherove - LinkedIn: https://www.linkedin.com/in/osherove/ ### Contact - Contact form: https://forms.gle/jQSx5KoXvrVA1JCK7 ### License Licensed under CC BY 4.0 — reuse, quote and adapt with attribution (Roy Osherove, link to the original page). License: https://creativecommons.org/licenses/by/4.0/