Testing Is Like Going To The Doctor

Introduction

By now, you’ve probably heard the phrase “move quality upstream.” The idea is that we want developers to take more ownership of the validating the quality of the code they produce. There are a couple of common sense practices–most of which you’ve already heard of–that you need to adopt to start moving your org in this direction.

The first practice you need to adopt is unit testing. If your org doesn’t embrace unit testing, this is the first thing you need to go fix. Fortunately there’s been a lot written about unit testing and about how to get a dev org to adopt unit testing as a best practice. There’s even an IEEE standard on how to approach unit testing, if you’re into that kind of thing.

The next practice you need to adopt is test automation. Everything I write is going to assume that you believe test automation is generally a good thing and that you’ve got a standard test harness that you can use to exercise the code under test. Maybe you bought a test harness off the shelf. Maybe you’re using an open source test framework. Maybe you’re a special, unique snowflake and your org has a test harness that’s completely internal. Whatever. The point is, I’m going to assume that you believe in writing tests that are automated, repeatable and maintainable. I’m also going to assume you have some automated sanity tests, and probably an automated way to build and deploy code. If you haven’t got these yet, there’s some great books and blogs out there that’ll help you get the job done.

Great. What’s Next?

OK. So you’ve adopted both unit testing and automated functional testing. You’ve got an automated build and an automated BVT system that tells you when the build is just plain broken. That’s great. The next thing you need to think about is how to move more of the functional testing of software into the hands of the dev that’s writing it.

It makes sense for dev to own at least some functional testing. If you think about it, every time we move code from a developer to a tester we’re introducing overhead. It’s like having to setup and tear down a stack during a function call, or like having to move from “on box” to “on rack” in a cloud computing environment. It’s a tiny cost that repeated hundreds of times add up to a really big cost. The problem is that functional testing is a really big problem space. Are we asking dev to take on basic happy path testing? What about pairwise or stress testing? What about negative testing?

Yes. Yes, to all of it. But we’re going to do it one piece at a time. And when we’re done, we’re still going to have a ton of other stuff to do as quality assurance professionals. It’ll just be different stuff than what we do today.

The first thing you need to ask yourself is, “What is the first thing I do when dev hands me a piece of code to test?” The next thing you need to ask yourself is, “Does this really need to be done at all?” Then ask, “If this needs to be done, am I really the right person to do it?”

The first thing that you do when dev hands you a piece of code is going to be different depending on the kind of software you’re shipping. If you own a web service, you might validate that basic browsing and payment processing are working. If you own a game, you might make sure the menus load. The thing is, there’s probably something that you always do first when a dev tells you that a piece of code is done.

That thing, whatever it is–do you really need to do it? Is it finding bugs? What’s the risk to your product if you don’t find a bug at this stage? If a test doesn’t find bugs and it doesn’t mitigate risk, it’s probably not worth running. If a test always finds bugs, then we need to do something to improve quality because consistent failure is a sign that something’s systemically wrong.

Here’s a table to illustrate the point:

Always find Bugs Rarely Finds Bugs
High Risk We need more quality before we run this test Somebody should run this test
Low Risk We need more quality before we run this test Don’t run the test

Is There A Doctor In The House?

A test in software is kind of like getting a test from the doctor. If the doctor finds that my blood pressure is high, I’m the one who gets on the treadmill to try to get my blood pressure down, not the doctor. If the tests find that something’s consistently wrong, the the developer needs to do something to rectify the consistent failure: more code review, more unit testing–or maybe running the functional test themselves.

If the doctor thinks that it’s worthwhile to have my blood pressure monitored, I could come into the office to do it but that’ll get expensive and time consuming really fast. Or I could buy a blood pressure cuff and monitor my vitals myself, which will be much cheaper. The automated test that you’ve been running every time your dev hands you code? That test is your automatic, home-use blood pressure cuff.

The key here is that the home blood pressure monitor is automatic. I push a button, it squeezes my arm like an anaconda, and it spits out a reading. I don’t need a stethoscope. I don’t even need to know how to spell “systolic”. If somebody hadn’t invented this nifty little automated testing device, I wouldn’t be able to do this test by myself. But they did, and I can, and it saves a ton of time and money.

So if your test is always finding bugs or if the area is high risk, take your automated test and say to your dev partner, “Hey, I run this test every time you hand me code. If you ran it instead it would save us both some time.”

I’m assuming, of course, that your automated test runs pretty quickly, doesn’t generate false failures, and don’t require mastery of the Dark Arts to setup and execute–just like the automated blood pressure cuff. As long as you meet these conditions with your tests, the win for everybody is usually pretty obvious. It’s exactly the same as not driving to the doctor when you have a home blood pressure cuff–don’t go to the tester when you’ve got a quick, easy way of validating quality yourself.

Advertisements

3 Responses

  1. […] • Тест тесту рознь: какие тесты кому и когда запускать. […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: