Toy Robot Simulator

A Go (Golang) implementation as per PROBLEM requirements.

The coding challenge was created by Jon Eaves at ANZ.

Over the past decade, it has been a common interview take home test for many companies.

I have decided to open source it because today many companies are using HackerRank, LeetCode, CodeSignal or their own custom tests and there are close to 1000 open source projects.

Architecture Overview

The project follows a clean, modular architecture, adhering to separation of concerns.

Below is a structural outline:

go-toyrobot/
├── main.go              # Entry point
├── ui/                  # User interface layer
├── cmd/                 # Command parsing
├── table/               # Game board logic
├── toy/                 # Robot entity
├── compass/             # Direction handling
├── unit/                # Coordinate types
└── doc/                 # Documentation

✅ Reviewed with Amazon Q for Dev CLI on 9 June 2025 for best practices and structural integrity.

Strengths

1. Excellent Test Coverage: 100% coverage across all packages
2. Clean Architecture: Well-separated concerns with clear interfaces
3. Type Safety: Custom types for coordinates and directions prevent errors
4. Robust Input Validation: Regex-based command parsing
5. Interface Design: Good use of interfaces for testability

Prerequisites

The code was originally written for Go 1.1 in Nov 2017, but in Mar 2025 I trialed Copilot Agent mode as a learning exercise to see if it could fix the code and upgrade it to Go version 1.23.1, as per this commit. Copilot Agent mode successfully upgraded the code to Go 1.23.1 and passed all tests within 30 minutes.

Ensure your Go version is up-to-date by executing go version.

If you don't have Go installed, you can download it from https://golang.org/dl/

Clone the project and initialize the Go module dependencies.

Steps to setup and run

git clone https://github.com/andrewbruno/go-toyrobot.git
cd go-toyrobot
make run

Extra Features

CLI accepts "q" to quit program

Testing via CLI

make test

Testing via file input

go run main.go < scenarioA.txt
go run main.go < scenarioB.txt
go run main.go < scenarioC.txt

Testing code coverage via GO

go test -cover ./...

Expected out:

        github.com/andrewbruno/go-toyrobot          coverage: 0.0% of statements
ok      github.com/andrewbruno/go-toyrobot/cmd      coverage: 100.0% of statements
ok      github.com/andrewbruno/go-toyrobot/compass  coverage: 100.0% of statements
ok      github.com/andrewbruno/go-toyrobot/table    coverage: 100.0% of statements
ok      github.com/andrewbruno/go-toyrobot/toy      coverage: 100.0% of statements
ok      github.com/andrewbruno/go-toyrobot/ui       coverage: 100.0% of statements
ok      github.com/andrewbruno/go-toyrobot/unit     coverage: 100.0% of statements

Why Go?

I started to learn Go in July 2016 at Raven Fly, while working remotely on ManyMe, a greenfield online privacy platform.

Why I enjoyed using Go:

• Built-in formatting eliminates style debates.
• Testing support out of the box encourages TDD.
• Less verbose than Java — no need for access modifiers.
• Statically typed for compile-time safety.
• Enforced use of variables prevents bloat.