For those of you that don't know, I'm somewhat of an amateur horologist. I love clocks, watches and all sorts of time and date keeping gadgets. To feed my passion I've decided to invest in my own custom made timepiece. This device will be my first custom made high value item, in what I hope will one day be a great collection.
To ensure I get what I want, I've taken some time and documented the following requirements for my new clock. They list what I want from the timepiece, and also what I don't want or need. Have a read through, and hopefully you'll see what it is I'm after.
A new clock should be developed for my new home in London.
The clock will need to:
- Display the time.
- Display in roman numerals and modern 'arabic' numerals.
- Be accurate enough for household use - approx' to with in a few minutes.
- Be ornamental - preferably with a intricately styled clock face.
- Have a traditional square brass clock face
- Be constructed from traditional clock materials like brass.
- Be water resistant - as it may be used in the garden.
- Resilient to wind - as it may be used in the garden.
- Not have a chime, bell, cuckoo or another form of 'noisy' time indicator.
- No special case or stand is required.
Now as a tester, I keep hearing that that we should all be writing up our test cases in advance. Sounds sensible, and assuming I have some documented requirements; I can get 'ahead of the game' and write my tests up front.
Ok, I've been bitten before. I'm not just going to write tests that check the system one way for each requirement. For example, 'Be water resistant', I'm not just going to splash a bit of water on the clock face. I'm going to splash water from at least three sides, and at least four different intensities of water.
I'll do that for each requirement. Creating a comprehensive suite of tests that I can use for testing the device when I receive it. I can also use them as a regression 'test pack' anytime in the future, without having to 'think'.
Now, lets jump forward in time. It's now the evening of 24th December 2011. My clock is sitting on the table, near the back door of my house. I've been impressed with my clock, I don't use it every day but when I have - It has worked well. But I look at it now - and I just can't figure out the time - something must be broken.
Take a look back at your tests - could they find the bug?
You can find a picture of the clock here. And a clue to why it isn't working here.