Memory fragment – 2023 · Day 9
I remember that statement generator.
It printed a nice summary, and the total looked right.
At least the first time.
But next time… the number changed.
...
Maybe the bug wasn’t in the maths, but in the way we let time and state creep in.
On the seventh day of the journey, we revisit the Day 9 memory from 2023:
The existing test passes… but is the behaviour really correct?
Today, the approach is different, we practice Bug Driven Development:
You are not allowed to change the production code
unless you have a failing test that shows the wrong behaviour.
Your mission:
- Understand the current behaviour
- Think of behaviours that might be wrong
- Write tests that expose the bug(s)
- Fix the code, one failing test at a time
Let the failing tests guide where and how to refactor.
Pick the stack you want to use as your main stack this year and open the Day 9 memory from 2023:
memories/2023/exercises/<your-stack>/day09
This is your playground.
On Discord, you can share for example:
- the first failing test you wrote and what bug it revealed,
- a before/after snippet of the
Clientdesign, - how your view of “where the bug really was” evolved.
If you want your work to be public, add your file to:
community/solutions/dayNN/by copying the template:
community/solutions/TEMPLATE-[replace_with_your_name].md- then open a pull request.
In journey/your-name.md, write a short entry for today:
- Which bug did I intentionally hunt first?
- What did my new tests say about the design I really wanted?
When the time loop surfaces a bug,
let the test be the lantern that shows you how to fix it. 🐛💡