is What?

npm i is-what

Very simple & small JS type check function

Motivation: I built is-what because the existing solutions were all too complex.

It's litterally just these functions:

function getType (payload) {
  return Object.prototype.toString.call(payload).slice(8, -1)
}
function isUndefined (payload) {
  return getType(payload) === 'Undefined'
}
function isNull (payload) {
  return getType(payload) === 'Null'
}
function isObject (payload) {
  return getType(payload) === 'Object'
}
function isFunction (payload) {
  return getType(payload) === 'Function'
}
function isArray (payload) {
  return getType(payload) === 'Array'
}
function isString (payload) {
  return getType(payload) === 'String'
}
function isNumber (payload) {
  return (getType(payload) === 'Number' && !isNaN(payload))
}
function isBoolean (payload) {
  return getType(payload) === 'Boolean'
}
function isRegExp (payload) {
  return getType(payload) === 'RegExp'
}
function isDate (payload) {
  return (getType(payload) === 'Date' &&  !isNaN(payload))
}

Since v2.0.0, checking for isNumber and isDate will return false if the payload is NaN or an invalid date.

Tests

npm run test