Quotes About Testing

Without tests every change is a possible bug. No

If you let the tests rot, then your code will rot too. Keep your tests clean.

Complexity kills. It sucks the life out of developers, it makes products difficult to plan, build, and test." —Ray Ozzie, CTO, Microsoft Corporation

What makes a clean test? Three things. Readability, readability, and readability.

If a test in the same package needs to call a function or access a variable, we'll make it protected or package scope.

The fact that we did not have a database running for 18 months of development meant that, for 18 months, we did not have schema issues, query issues, database server issues, password issues, connection time issues, and all the other nasty issues that raise their ugly heads when you fire up a database. It also meant that all our tests ran fast, because there was no database to slow them down.

Architecture is a hypothesis, that needs to be proven by implementation and measurement. —Tom Gilb

Am I suggesting 100% test coverage? No, I'm not suggesting it. I'm demanding it. Every single line of code that you write should be tested. Period.

Try to write tests that force exceptions, and then add behavior to your handler to satisfy your tests. This will cause you to build the transaction scope of the try block first and will help you maintain the transaction nature of that scope.

You should be able to run all the unit tests with just one command.

The tests fit the production code like an antibody fits an antigen.

Am I suggesting 100% test coverage? No, I'm not suggesting it. I'm demanding it. Every single line of code that you write should be tested. Period. Isn't that unrealistic? Of course not. You only write code because you expect it to get executed. If you expect it to get executed, you ought to know that it works. The only way to know this is to test it.

The moral of the story is simple: Test code is just as important as production code. It is not a second-class citizen. It requires thought, design, and care. It must be kept as clean as production code.

Test code is just as important as production code. It is not a second-class citizen. It requires thought, design, and care. It must be kept as clean as production code.

The Three Laws of TDD You are not allowed to write any production code until you have first written a failing unit test. You are not allowed to write more of a unit test than is sufficient to fail—and not compiling is failing. You are not allowed to write more production code that is sufficient to pass the currently failing unit test.

Structured programming forces us to recursively decompose a program into a set of small provable functions. We can then use tests to try to prove those small provable functions incorrect. If such tests fail to prove incorrectness, then we deem the functions to be correct enough for our purposes.

Men of great abilities are slow to act. for it is easier to avoid occasions for committing yourself than to come well out of a commitment. Such occasions test your judgment; it is safer to avoid them than to emerge victorious from them. One obligation leads to a greater one, and you come very near to the brink of disaster. BALTASAR GRACIÁN, 1601-1658

Test for Envy

The German philosopher Arthur Schopenhauer devised a quick way to test for envy. Tell suspected enviers some good news about yourself—a promotion, a new and exciting love interest, a book contract. You will notice a very quick expression of disappointment

That young man seeks opportunities to test his principles as readily as a drunk picks fights in a bar.

I also hope to challenge financial thinkers to improve their theories by testing them against the impressive evidence that suggests that the price level is more than merely the sum of the available economic information, as is now generally thought to be the case.

Thank you, the young mother said again. Thank you. The Black Tower protects, Logain heard himself say. Always. I will send him to you to be tested when he is of age, the woman promised, holding her son. I would have him join you, if he has the talent. The talent. Not the curse. The talent.

His work was just barely passing by academic standards at this time, but this wasn't because he wasn't working or thinking. He was thinking too hard, and the harder you think in this high country of the mind the slower you go. Phaedrus read in a scientific way rather than a literary way, testing each sentence as he went along, noting doubts and questions to be resolved later, and I'm fortunate in having a whole trunkful of volumes of these notations

A man conducting a gee-whiz science show with fifty thousand dollars' worth of Frankenstein equipment is not doing anything scientific if he knows beforehand what the results of his efforts are going to be. A motorcycle mechanic, on the other hand, who honks the horn to see if the battery works is informally conducting a true scientific experiment. He is testing a hypothesis by putting the question to nature.