Connect4 — interview practice

Mini TS project for practicing the classic Connect4 problem under live-coding conditions.

Setup

cd connect4
npm install

Workflow

1. Open src/Connect4.ts — stub class, all methods throw.
2. Run tests in watch mode:

   npm test

3. Implement until green. Try to do it in one sitting, no AI help.

Rules of the game

• 6 rows × 7 columns. Row 0 is the bottom (gravity drops discs down).
• Red ("R") moves first; players alternate.
• Win: 4 in a row horizontally, vertically, or diagonally.
• playMove returns [row, col] where the disc landed.
• Invalid moves (bad column, full column, game already over) throw Connect4Error.

Reset for another run

git stash      # or just revert src/Connect4.ts