Comments on: Harold’s Corollary to Knuth’s Law

By: A Smattering of Selenium #62 « Official Selenium Blog

A Smattering of Selenium #62 « Official Selenium Blog — Thu, 29 Sep 2011 14:06:11 +0000

[...] from the vaults is Harold’s Corollary to Knuth’s Law which is aimed at Unit not Functional tests, but still is food for [...]

By: Ken

Ken — Thu, 01 Sep 2011 18:13:58 +0000

Whoops, my bad. I was thinking of “black box” testing

By: Ken

Ken — Thu, 01 Sep 2011 18:07:55 +0000

How about “unit” tests that execute their own SQL queries that bear no relationship to any existing application and distorts the whole intent of the DB?
I have to admit that calling tests that execute the actual code being used as “unit” is foreign to me. Those seem like “white box” to me.

By: Yves Daoust

Yves Daoust — Thu, 01 Sep 2011 15:30:45 +0000

Mh, I don’t love the second part that says “Code coverage should be as near 100% as possible.” Given the number of inputs and complexity of real-life programs, I have the impression that coverage often looks like 0.0000000001%. I’d prefer something like “Code coverage should be near 100% of what is economically sensible.”

My favorite advice regarding coverage is: “test first what the user will do first”. It takes some hindsight to figure out what others will be doing with your code, but these are the places where bugs will mostly harm.

I agree with the other two parts.

By: BrianW

BrianW — Thu, 01 Sep 2011 13:09:54 +0000

> Mocks are an abomination, requiring far too much effort to build

I agree with “Name Required”: you’re doing them wrong. You’re probably either attempting to mock something that is too complex – which should be a smell to you – or you’re using the wrong mocking library.

By: WanderMelee

WanderMelee — Thu, 01 Sep 2011 05:22:29 +0000

Carguous Noll (local to the Breenda area) gave an experience report about the influence of “end-to-end integrated tests” and “unit tests” on the software being developed.

Unit tests (actually, “microtests” like those produced in TDD) did NOT help improve the design of the code, did NOT help find where the bugs are (they might reveal a previously-undiscovered bug, but don’t tell you where it is), etc.

End-to-end integrated tests influenced the design of the code to be more de-coupled, helped localize bugs, etc. And were run more often, catching problems faster.

(Apologies to Carguous if I mis-remembered or mis-represented his presentation several years ago.)

So there.

By: No to premature optimization | Software Development with Linux

No to premature optimization | Software Development with Linux — Wed, 31 Aug 2011 18:14:40 +0000

[...] to Kent Beck for sharing Harold’s Corollary To Knuth’s Law. Donald Knuth wrote, in Structured Programming with go to Statements : “Premature [...]

By: Keith Ray

Keith Ray — Wed, 31 Aug 2011 16:37:29 +0000

Dave Smith (local to the SF Bay area) gave an experience report about the influence of “end-to-end integrated tests” and “unit tests” on the software being developed.

End-to-end integrated tests did NOT help improve the design of the code, did NOT help find where the bugs are (they might reveal a previously-undiscovered bug, but don’t tell you where it is), etc.

Unit tests (actually, “microtests” like those produced in TDD) influenced the design of the code to be more de-coupled, helped localize bugs, etc. And were run more often, catching problems faster.

(Apologies to Dave if I mis-remembered or mis-represented his presentation several years ago.)

By: J. B. Rainsberger

J. B. Rainsberger — Mon, 27 Apr 2009 14:13:26 +0000

As a counterpoint to your article, Elliotte, Integration Tests are a Scam: http://www.jbrains.ca/category/integration-tests-are-a-scam or http://tinyurl.com/dz2ftu

By: Name required

Name required — Mon, 22 Dec 2008 15:47:24 +0000

> Mocks are an abomination, requiring far too much effort to build

You’re doing them wrong.