About jwgrenning

Hi I've been developing and managing software for decades now. Starting in embedded, but doing more than embedded. Many of the mainstream software development techniques have crossover value to embedded. My mission is to spread some of those techniques to the embedded community. My company is Wingman Software. Please visit my site.

TDD Stepping Stones

Imagine you are trying to cross a mountain stream. You could make a running leap and get to the other side. Sometimes that works, other times you get wet. When there are rocks sticking out of the rushing water, you can step from rock to rock and get across the stream without getting wet. Sure there are some streams you can jump across, go ahead and jump. Other streams require a more careful approach.
Continue reading

Learning Tests are Free!

My son is studying computer science at U of I in Chicago. He is taking an operating systems class and has to do some projects in C. (Some things change, some things stay the same.) He had an internship over the last 8-9 months and was doing TDD in Java. So he might be in the early stages of a test infection.

He has not done much C so he’s got some learning to do. I thought I better show him CppUTest. He could use it for a play ground to learn some of the subtleties of C, as well as use TDD.
Continue reading

Crashing Your Way to Great Legacy C Tests

Adding tests to legacy C or C++ code can be a challenge. Code not designed to be tested won’t naturally be testable. Dependencies will be unmanaged and invisible. Getting that first test written will hurt, a lot. Don’t despair! The first test is the hardest, but subsequent tests are much easier.

Knowing what to do and what to expect, when you start adding tests to your legacy code, can ease the journey. This article will give you an idea of what to expect when getting that first bit of C or C++ into the test harness.
Continue reading

TDD and the Big Framework Part II

In TDD next to the Big Framework we looked at a design that helps to isolate your code from the BigFramework. That article only showed half the story. Lot’s of times the big framework has the attitude “don’t call us, we’ll call you” built right in. Your code has to register somehow with the framework, then when you ask it to do things, it calls you back, asynchronously, with the result.
Continue reading

Coaching ramblings from China

I’m just completing my fourth trip to China to coach Chinese engineers in TDD. I’ve learned a few things, I hope, about coaching people who don’t speak my language as a first language. I also had occasion to use what little I know on the subject while at the Scrum gathering in Shanghai, the first in China. Before I get into that, let me tell you about my adventure getting the the Scrum gathering.
Continue reading

Speak to me Vikki

My friend Bas introduced me to Vikki, the computerized text-to-speach voice on my Mac. I had met her once before but thought, what good is she? I don’t need text-to-speech.

Vikki is becoming a very valuable companion helping me to write my book on TDD for Embedded C. Like many writers I have heard from, I find it very difficult to find problems with what I have just written. Jeff Langr suggested reading out-loud as part of the proof reading process. That helped a lot. But I often still read what was in my head rather than what was on the page.

With Vikki by my side, I can select a paragraph and have her read to me. She sounds a little like a Scandinavian that has had a few, but she actually reads what is there on the page. I even have discovered
I can edit out the problems as she is reading.

Thanks Bas. Thanks Jeff. Thanks Vikki.

TDD next to the Big Framework

TDD next to the Big Framework

We’re trying to create a new executable process that plugs into a pretty big services framework for a telecom system. Our code and framework are in C++. We’re test driving our design. Within a few tests, we were confronted with having to inherit from a framework class. No big deal, or so we thought. Soon the dependency chains became evident. Kind of like this picture, but worse. Continue reading