Getting Started

Testing a CLI isn't like testing a library—you can't just import functions and call them. You need to spawn your CLI as a subprocess, give it real files to work with, and capture its output. bintastic simplifies this: it creates a temporary project directory, runs your binary against it as a real subprocess, and hands back the exit code, stdout, and stderr for assertion.

Formerly @scalvert/bin-tester

This package was previously published as @scalvert/bin-tester.

Install

npm add bintastic --save-dev

Quick start

Point bintastic at your binary, set up a project before each test, and run the bin against fixture files:

import { createBintastic } from 'bintastic';

describe('my-cli', () => {
  const { setupProject, teardownProject, runBin } = createBintastic({
    importMeta: import.meta,
    binPath: './bin/my-cli.js', // resolved relative to this test module
  });

  let project;

  beforeEach(async () => {
    project = await setupProject();
  });

  afterEach(() => {
    teardownProject();
  });

  test('processes files', async () => {
    await project.write({ 'input.txt': 'hello' });

    const result = await runBin('input.txt');

    expect(result.exitCode).toBe(0);
    expect(result.stdout).toContain('processed');
  });
});

setupProject creates a fresh temp directory, project.write() writes the fixtures your CLI should see, runBin executes the binary against them, and teardownProject cleans up.

From here, see Usage for the full set of options and helpers, Debugging for inspecting failing runs, and the API Reference for generated type documentation.