Developing Tic-Tac-Toe

Are you ready to code? Let's start with the first requirement.

Requirement 1 – placing pieces

We should start by defining the boundaries and what constitutes an invalid placement of a piece.

A piece can be placed on any empty space of a 3×3 board.

We can split this requirement into three tests:

• When a piece is placed anywhere outside the x-axis, then RuntimeException is thrown
• When a piece is placed anywhere outside the y-axis, then RuntimeException is thrown
• When a piece is placed on an occupied space, then RuntimeException is thrown

As you can see, the tests related to this first requirement are all about validations of the input argument. There is nothing in the requirements...