@small-tech/required/test/index.js

Add required argument checking to your functions.

const test = require('tape')
const required = require('..')

function needsPuppy (puppy = required('puppy')) {
  // A puppy is required.
}

function needsGeneric (generic = required()) {
  // We won’t know the name of what’s required.
}

test('required', t => {
  t.plan(4)
  try {
    needsPuppy(/* oh no, no puppy */)
  } catch (error) {
    t.ok(error instanceof Error, 'error should be an Error instance')
    t.strictEquals(error.message, 'Missing argument (puppy).', 'it should complain about the missing puppy')
    t.strictEquals(error.stack.match(/at required/), null, 'error helper should not feature in stack trace')
  }

  try {
    needsGeneric()
  } catch (error) {
    t.strictEquals(error.message, 'Missing argument.', 'it should complain about generic missing argument')
  }
})