tezt

Easy Tests

Note: this is still in beta, and the api is likely to change

This is a minimalistic testing library that doesn't usurp control of your node process.

The advantages of this library are:

• Works out of the box with typescript or javascript files
• Easy to use with VS Code or Google Chrome's debugger
• Source map lines don't get messed up
• Compatible with jest and mocha (although not all features are implemented yet)
• You can run a test file as you would a normal file

Installation

In your project:

yarn add --dev tezt

or

npm i --save-dev

Additionally, for command line use (which you probably want):

yarn global add tezt

or

npm i -g tezt

You need tezt installed globally for it to work locally.

Writing test files

Implementation is as easy as importing your module, declaring your tests, and running that file.

import {
  test,
  describe,
  before,
  after,
  afterEach,
  beforeEach,
  expect
} from 'tezt'

test('this is my test', () => {
  expect('hello').toBe('hello')
})

test.skip(`this test won't be run`, () => {
  throw new Error('This is never thrown')
})

describe('I can describe a group of tests', () => {
  before(() => {
    console.log('this is run before all tests in this describe block')
  })

  after(() => {
    console.log('this is run after all tests in this describe block')
  })

  test.skip('this test won\'t run', () => {
    console.log('this is never output')
  })


  test.only('this is the only test that will be run aside from the describe.only tests', () => {
    throw new Error('This error will be thrown, but the rest of the tests will still run')
  })

  test(`this test won't be run, because it didn't specify only`, () => {
    console.log('this is not run')
  })

  describe('I can nest as many describes as I want', () => {
    test('and they can include as many', () => {
      console.log('tests as they want')
    })
  })
})

describe('You can also run beforeEach and afterEach test', () => {
  beforeEach(() => {
    console.log('this will output before each test')
  })
  afterEach(() => {
    console.log('this will output after each test')
  })
  for (let i = 0; i < 5; i++) {
    test(`test ${i}`, () => {})
  }

})

describe.only('describes can also be onlys, and all tests contained ', () => {
  test('will be run (unless there\'s another only in the describe', () => {})
})

test('I can also run asynchonous tests', async () => {
  await new Promise((res, rej) => {
    expect('the test will not return until the promise has resolved').toBeTruthy()
    res()
  })
})

Additional Functions

In addition to the jest/mocha api, there are also additional functions exported by tezt:

expect: Michael Jackson's library globalBeforeAll: a function run before all functions in all files

• useful for adding global setup like starting a testing server globalAfterAll: a function run after all functions in all files
• useful for adding global teardown like stopping a testing server only: like test.only, except only runs that particular file skip: like test.skip, except skips that particular file

Running tests

Once you've created the test file, you can run it like a normal file:

ts-node '<yourfilename>'

You can also run that same file with the command line tool:

tezt <yourfilename>

You can also watch that test file, so node will not have to bootload its runtime every time you want to run a test suite.

tezt <yourfilename> -w

You can also run multiple files at the same time:

tezt <yourfilename> <yoursecondfilename>

If a directory is specified, tezt will crawl all children of the directory and run all the test files.

tezt <my-dir>

If you don't specify any files or directories, it will default to your cwd:

tezt

Configuration

You can add a config file to the root of your project:

// tezt.config.js
module.exports = {
  // glob for test files
  testPatterns: '**/*.{test,spec}.{js,ts}',
  // globs of files to ignore
  ignorePatterns: ['node_modules/**', 'dist/**', 'build/**'],
  // globs for files to watch for changes when using --watch
  watchPatterns: ['**/*.{ts,js}'],
  // test files and directories of files too look in for test files
  testPaths: [__dirname],
  // emulate the dom during tests
  dom: false,
  // whether or not to look for an exported "test" function
  fns: false,
}

or you can use command line flags (with 'src' as the test directory):

tezt --test-patterns|-t '**/*.{test,spec}.{js,ts}' \
  --ignore-patterns|-i 'node_modules/**' 'dist/**' 'build/**' \
  --watch-patterns|--wp '**/*.{ts,js}' \
  src

Use with Create React App

To use this with CRA, you'll need to add the following to your tsconfig.json:

  "ts-node": {
    "compilerOptions": {
      "module": "commonjs"
    }
  },

Use with @testing-library/react

You'll want to extend the expect function and use --dom with your config:

tezt --dom

// setupTests.ts

import { expect, globalBeforeAll } from 'tezt'

declare var global:any;
globalBeforeAll(async () => {
  global.expect = expect
  await import('@testing-library/jest-dom/extend-expect')
  delete global.expect
})

add

declare module '@testing-library/react'

to react-app-env.d.ts

Test Current File in VS Code

Add this to your launch.json file (in .vscode):

    {
      "name": "Test Current File",
      "type": "node",
      "request": "launch",
      "program": "${workspaceRoot}/${relativeFile}",
      "cwd": "${workspaceRoot}/server",
      "runtimeArgs": [
        "-r",
        "ts-node/register",
      ],
      "env": {
        "FORCE_COLOR": "1",
        "NODE_ENV": "test",
      },
      "skipFiles": [
          "<node_internals>/**/*.js",
      ],
    }

Related

jest mocha

TODO

• add snapshotting
• should be able to run global tezt from a parent directory, and it run tezt on all sub directories that have tezt installed
  • note: this will require removing duplicates...so if there's a duplicate
• console.log(require.cache)
• preload node_modules - add an option for a file to run before tests have started