proby

Test runner for JavaScript runtimes.

What is proby?

A cross-runtime test runner that automatically discovers and runs test files. Works with both single repositories and monorepos. Uses @rcompat/test for writing tests. Works consistently across Node, Deno, and Bun.

Installation

npm install proby

pnpm add proby

yarn add proby

bun add proby

You also need to install @rcompat/test as a peer dependency:

npm install @rcompat/test

Usage

Running tests

Run proby from your project root:

npx proby

Writing tests

Create test files with .spec.ts or .spec.js extension in your src directory:

// src/math.spec.ts
import test from "@rcompat/test";

test.case("addition", assert => {
  assert(1 + 1).equals(2);
  assert(2 + 2).equals(4);
});

test.case("multiplication", assert => {
  assert(2 * 3).equals(6);
  assert(4 * 5).equals(20);
});

Test output

Proby displays colored output:

• Green o for passing tests
• Red x for failing tests

oooooxoo
src/math.spec.ts division
  expected  5
  actual    4

Project structure

Proby automatically detects your project structure:

Single repository:

my-project/
├── src/
│   ├── utils.ts
│   ├── utils.spec.ts    # ← Test file
│   ├── math.ts
│   └── math.spec.ts     # ← Test file
└── package.json

Monorepo:

my-monorepo/
├── packages/
│   ├── core/
│   │   └── src/
│   │       ├── index.ts
│   │       └── index.spec.ts  # ← Test file
│   └── utils/
│       └── src/
│           ├── helpers.ts
│           └── helpers.spec.ts  # ← Test file
└── package.json

npm scripts

Add proby to your package.json:

{
  "scripts": {
    "test": "npx proby"
  }
}

Then run:

npm test

Test file conventions

• Files must end with .spec.ts or .spec.js
• Files must be in the src directory (or packages/*/src for monorepos)
• Use @rcompat/test to write tests

Examples

Basic assertions

import test from "@rcompat/test";

test.case("basic assertions", assert => {
  // equality
  assert(value).equals(expected);

  // truthiness
  assert(condition).true();
  assert(condition).false();

  // type checking
  assert(value).type<string>();

  // throws
  assert(() => throwingFunction()).throws();
  assert(() => safeFunction()).tries();
});

Async tests

import test from "@rcompat/test";

test.case("async operations", async assert => {
  const result = await fetchData();
  assert(result.status).equals(200);
});

Testing modules

// src/calculator.ts
export function add(a: number, b: number) {
  return a + b;
}

// src/calculator.spec.ts
import test from "@rcompat/test";
import { add } from "./calculator.js";

test.case("add function", assert => {
  assert(add(1, 2)).equals(3);
  assert(add(-1, 1)).equals(0);
  assert(add(0, 0)).equals(0);
});

Cross-Runtime Compatibility

| Runtime | Supported | |---------|-----------| | Node.js | ✓ | | Deno | ✓ | | Bun | ✓ |

No configuration required — just run npx proby.

License

MIT

Contributing

See CONTRIBUTING.md in the repository root.