A useful resource to follow is Aditya Rohilla’s “The System Design Template I Use”. The template follows those headlines.

Overview (Optional)

Outlines the technical approach to solving the “Tennis Calculator” challenge for EstimateOne.

This document is primarily aimed at planning out the problem and sharpening the proverbial saw before cutting down the tree implementing the solution.

It may also be used to demonstrate my usual approach to problems.

This process is helpful to clarify knowns/unknowns and is an initial documentation for the planned approach and not the final approach.

(I may add a section to clarify pivots.)

Problem

Refer to the provided README for the challenge.

The tl;dr is that we want to be able to query input from a file for an altered tennis match.

• Given a match ID, we want to determine the winner of a match.
• Given a player name, we want to determine their win-loss ratio.

Tenets (Optional)

• Keep it simple.
• Single-responsibility functions.
• “Replay-ability” through state-reducer pattern (treat scores as a ledger that arrives at state as opposed to maintaining a single source of truth).
• Separation of concerns (for calculating match vs player history).
• Pure functions when no side-effects are required.
• Use libs to enhance TypeScript DX for building a CLI tool.
• TDD all pre-defined units.