@scalvert/bin-tester

Provides a test harness for node CLIs that allow you to run tests against a real project.

Install

npm add @scalvert/bin-tester --save-dev

# or

yarn add @scalvert/bin-tester --dev

Usage

@scalvert/bin-tester uses two libraries to provide the test harness:

• fixturify-project: Allows you to dynamically create test fixtures using real directories and files in a tmp directory
• execa: A better replacement for child_process.exec

It combines the above and provides an API for running a binary with a set of arguments against a real project structure, thus mimicking testing a real environment.

import { createBinTester } from '@scalvert/bin-tester';

describe('Some tests', () => {
  let project;
  let { setupProject, teardownProject, runBin } = createBinTester({
    binPath: 'node_modules/.bin/someBin',
    staticArgs: ['--some-arg'], // pass some args to the bin that will be used for each invocation
  });

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

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

  // Run the bin and do something with the result
  test('a test', async () => {
    const result = await runBin();

    expect(result.stdout).toBe('Did some stuff');
  });

  test('another test', async () => {
    // Write a file with contents to the tmp directory
    await project.writeDirJSON({
      'some/file.txt': 'some content',
    });

    // pass some args to the bin that will be used for only this invocation
    const result = await runBin('--path', 'some/file.txt');

    expect(result.stdout).toBe('Read "some/file.txt"');
  });
});

API

Classes

Functions

BinTesterProject

Kind: global class

• BinTesterProject
  • new BinTesterProject(name, version, cb)
  • .gitInit() ⇒ *
  • .chdir()
  • .dispose() ⇒ void

new BinTesterProject(name, version, cb)

| Param | Type | Default | Description | | --- | --- | --- | --- | | name | string | "fake-project" | The name of the project. Used within the package.json as the name property. | | version | string | | The version of the project. Used within the package.json as the version property. | | cb | function | | An optional callback for additional setup steps after the project is constructed. |

binTesterProject.gitInit() ⇒ *

Kind: instance method of BinTesterProject
Returns: * - {execa.ExecaChildProcess}

binTesterProject.chdir()

Kind: instance method of BinTesterProject

binTesterProject.dispose() ⇒ void

Kind: instance method of BinTesterProject

createBinTester(options) ⇒ CreateBinTesterResult.<TProject>

Kind: global function
Returns: CreateBinTesterResult.<TProject> -

| Param | Type | Description | | --- | --- | --- | | options | BinTesterOptions.<TProject> | An object of bin tester options |

• createBinTester(options) ⇒ CreateBinTesterResult.<TProject>
  • ~runBin(...args) ⇒ execa.ExecaChildProcess.<string>
  • ~setupProject()
  • ~setupTmpDir()
  • ~teardownProject()

createBinTester~runBin(...args) ⇒ execa.ExecaChildProcess.<string>

Kind: inner method of createBinTester
Returns: execa.ExecaChildProcess.<string> - An instance of execa's child process.

| Param | Type | Description | | --- | --- | --- | | ...args | RunBinArgs | Arguments or execa options. |

createBinTester~setupProject()

Kind: inner method of createBinTester

createBinTester~setupTmpDir()

Kind: inner method of createBinTester

createBinTester~teardownProject()

Kind: inner method of createBinTester