Execute As Promise (executeAsPromise)

executeAsPromise is a simple package that allows you to execute any function as if it were a Promise (even if it isn't!).

This can be useful when you don't know in advance whether a function will be a Promise or not, but still want to keep a clean then().catch()-chain in your code.

executeAsPromise works by executing the function that is being passed, and then evaluating the result.

If it looks like a Promise it will return the Promise itself. If the function result doesn't look like a Promise, it will wrap it inside a new Promise and return that instead.

Installation

Install executeAsPromise through NPM:

npm install @michieljs/execute-as-promise

Usage

Import executeAsPromise in your code:

import executeAsPromise from '@michieljs/execute-as-promise'

Next you can use it in your code:

const normalFunction = () => {
  return 'my result'
}

executeAsPromise(normalFunction).then(console.log)

const promiseFunction = new Promise((resolve, reject) => {
  let rand = Math.random()
  if (rand >= 0.5) {
    resolve('Failure')
  } else {
    reject('Success!')
  }
})

executeAsPromise(promiseFunction)
  .then(console.log)
  .catch(console.error)

const valueNotAFunctionAtAll = 10

executeAsPromise(valueNotAFunctionAtAll).then(console.log)

The executeAsPromise-method accepts 3 parameters:

• function to execute (a Promise, a normal Function or even a String or Number)
• array of arguments to be apply-ed to the function (optional, defaults to null)
• context (or scope) for the function execution (optional, default to null)

const fullName = function(firstName, lastName) {
  return firstName + ' ' + lastName
}

executeAsPromise(myFunction, ['John', 'Doe])

Tests

To execute the unit tests run:

npm run test

License

MIT

Copyright (c) Michiel van der Geest