Barebones testing and test-runner for node >= 13

package.json

{
  "scripts": {
    "test": "node ./path-to/test-runner.mjs"
  }
}

test-framework.mjs

import { inspect } from 'util'

export default function test(name, fn) {
  try {
    fn()
  } catch (error) {
    console.error(name, inspect(error, false, null, true))
  }
}

test-runner.mjs

import fs from 'fs'
import path from 'path'

walkSync(`${process.cwd()}/src`).forEach(filename => {
  if (filename.endsWith('.spec.mjs')) {
    import(filename)
  }
})

// https://gist.github.com/kethinov/6658166#gistcomment-1921157
function walkSync(dir, fileList = []) {
  fs.readdirSync(dir).forEach(file => {
    if (fs.statSync(path.join(dir, file)).isDirectory()) {
      fileList = walkSync(path.join(dir, file), fileList)
    } else {
      fileList.push(path.join(dir, file))
    }
  })

  return fileList
}