HACKING.md

Better Go Playground Development Guide

Introduction

Welcome, gentle reader. This document explains project structure and describes steps to setup a development environment.

If you have any suggestions to improve this document, please feel free to submit a PR.

Glossary

Term	Description
FE	Front-end web application.
BE	Back-end, REST API service.
WASM	WebAssembly.

Project Components

Backend

REST API service (BE) written in Go which is responsible for:

• Proxying requests to original Go Playground to get snippets and run programs.
• Building WebAssembly executables to run programs in a browser.
• Provide basic autocomplete for Go standard library symbols in editor.

Note

Server main package is located in cmd/playground directory.

Front-end App

Front-end app (FE) provides user interface to write and execute Go programs in browser.

App is written in TypeScript and uses following libraries and tools:

• React
• Redux
• Monaco editor
• Fluent UI React components library.
• Vite

Note

FE app is located in web directory.

WebAssembly Programs

FE app relies on a set of WASM programs written in Go for language-specific tasks like syntax checking and etc.

WASM Go programs are located in cmd/wasm directory.

Package	Description
analyzer	Very simple Go syntax checker.

Tools & Scripts

Project uses a set of Go programs to prepare assets necessary for a project.

Name	Description
pkgindexer	Collects list of Go packages and symbols into JSON file for FE app autocomplete.

Note

Tools are located in tools directory.

Development Environment Setup

Prerequisites

Please ensure that you have installed:

• GNU or BSD Make
• Git
• Node Version Manager or Node.js 20 (lts/iron)
• Yarn package manager.
• Go 1.22+
• Protobuf:
  • protoc
  • Protobuf Go plugins

First-time setup

Run following commands to configure a just cloned project:

Command	Purpose
corepack enable	Enables Corepack to use package manager version from package.json
make preinstall	Installs NPM packages for a web app.
make wasm	Builds WebAssembly binaries used by the web app.
make go-index	Generates Go packages index for autocomplete in web app.

Running Project

Important

If you see command not found: yarn error, please ensure that Corepack is enabled. See First-time setup section.

Front-end web app and Go API server are executed using separate make commands:

Command	Purpose
make run	Starts Go API web server.
make ui	Starts Vite dev server with web app.

Backend is running at port 8000 and front-end is running on port 3000.

Tip

All API requests to backend are already proxied by Vite dev server.