jest-roblox assassin

jestrbx is a CLI tool for running Jest-style tests against Roblox places, wrapping the Roblox Jest runtime and rewriting results for local source paths. It is designed to integrate with roblox-ts and Rojo workflows, providing a familiar Jest experience for Roblox game development.

Features

• Runs Jest tests inside Roblox places using the JestCore runtime
• Maps Roblox datamodel paths back to local workspace files for readable output
• Supports custom and built-in Jest reporters
• CLI options are dynamically pulled from Roblox Jest docs
• Integrates with roblox-ts, Rojo, and standard TypeScript workflows
• Handles source mapping for .ts, .tsx, .lua, and .luau files
• Filters tests by name or path
• Supports coverage reporting through --coverage (see below for setup)
• Supports parallel execution through --maxWorkers

Getting Started

Prerequisites

• Node.js v22+ (recommended v24+)
• roblox-ts and Rojo (for TypeScript workflows)

Installation

Clone this repository and install dependencies:

npm install

Usage

Run tests against a Roblox place file:

npx jestrbx --place path/to/place.rbxl

For a full list of options, run:

npx jestrbx --help

Cloud Execution

It's recommended to run tests through Roblox Open Cloud. Create a .env file with a ROBLOSECURITY field:

ROBLOSECURITY=your_roblosecurity_cookie_here
# or if you want to load balance across multiple accounts:
ROBLOSECURITY=cookie1,cookie2,cookie3

More information about setting up the ROBLOSECURITY variable can be found here: https://github.com/Unreal-Works/roblox-luau-execute

Coverage

Coverage reporting requires a valid coverage instrumentation library:

• Wally: https://wally.run/package/evilbocchi/roblox-coverage
• roblox-ts: npm i @rbxts/coverage

To enable coverage reporting, use the --coverage flag:

npx jestrbx --place path/to/place.rbxl --coverage

Example Project

See the demo/ directory for a sample roblox-ts project with Jest tests configured.

Build and test with:

cd demo
npm run build   # Builds with roblox-ts and Rojo
npm test        # Runs tests with jest-roblox-assassin

License

MIT