Test Driven Approach - Positive Impact for Developers - Workshop I

Start from this post and over the next few posts, I will be covering the Test Driven Approach - Positive Impacts for Developers.

Impacts: -
1. Think like a user
2. Clean APIs Design
3. Improves Abstractions
4. Better Used of Patterns
5. Improves Separation of Concerns.

Let starts with some fundamental user requirements on a calculator.

I can do fundamental calculation, +, -, *, /, sqrt, %, pow and 1/x.
I can use whole numbers or rational numbers as the input.
I can defined the result format within the format of whole number or rational number.
I can specify the number of decimal places for the results.
I can define a formula and save it.
I can load a formula and calculate using the loaded formula.
I can only specify the values for variables within the formula.

There is all we have for the requirements.

So, if we're to start right away, we should have start writing the unit tests first.

A quick glance into the requirements, it seems quite straight forward to accomplish.

Questions: -
1. How many of you already start thinking of classes for logic separation, like Adder, Subtractor, Divisor and Multiplicator etc.?

2. How many of you already start writing unit tests right away based on the requirement defined?

"If there is anyone falling into those traps, you're wrong!" The requirement wasn't quite defined into a stage where this can be started.

Based on the requirements given, we should have at least asking how would it be deployed? Web Services, Windows Services, Web Apps or Windows Forms Apps for instance.

So, to make it more simple, this is a Win Form application, just like the calculator in Windows.

New User Requirements: -
"I can use it like many windows desktop application."

So now, we are good to start, however, not unit testing yet. It is the UI wireframe (prototyping for GUI, i.e. Forms.) Here it is: -



Now, we can start writing some tests, that will be in workshop II.