spaceout/site/frontend/node_modules/typical/index.mjs

270 lines
5.8 KiB
JavaScript

/**
* Isomorphic, functional type-checking for Javascript.
* @module typical
* @typicalname t
* @example
* const t = require('typical')
* const allDefined = array.every(t.isDefined)
*/
/**
* Returns true if input is a number. It is a more reasonable alternative to `typeof n` which returns `number` for `NaN` and `Infinity`.
*
* @param {*} - the input to test
* @returns {boolean}
* @static
* @example
* > t.isNumber(0)
* true
* > t.isNumber(1)
* true
* > t.isNumber(1.1)
* true
* > t.isNumber(0xff)
* true
* > t.isNumber(0644)
* true
* > t.isNumber(6.2e5)
* true
* > t.isNumber(NaN)
* false
* > t.isNumber(Infinity)
* false
*/
export function isNumber (n) {
return !isNaN(parseFloat(n)) && isFinite(n)
}
/**
* A plain object is a simple object literal, it is not an instance of a class. Returns true if the input `typeof` is `object` and directly decends from `Object`.
*
* @param {*} - the input to test
* @returns {boolean}
* @static
* @example
* > t.isPlainObject({ something: 'one' })
* true
* > t.isPlainObject(new Date())
* false
* > t.isPlainObject([ 0, 1 ])
* false
* > t.isPlainObject(/test/)
* false
* > t.isPlainObject(1)
* false
* > t.isPlainObject('one')
* false
* > t.isPlainObject(null)
* false
* > t.isPlainObject((function * () {})())
* false
* > t.isPlainObject(function * () {})
* false
*/
export function isPlainObject (input) {
return input !== null && typeof input === 'object' && input.constructor === Object
}
/**
* An array-like value has all the properties of an array yet is not an array instance. An example is the `arguments` object. Returns `true`` if the input value is an object, not `null`` and has a `length` property set with a numeric value.
*
* @param {*} - the input to test
* @returns {boolean}
* @static
* @example
* function sum(x, y){
* console.log(t.isArrayLike(arguments))
* // prints `true`
* }
*/
export function isArrayLike (input) {
return isObject(input) && typeof input.length === 'number'
}
/**
* Returns true if the typeof input is `'object'` but not null.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isObject (input) {
return typeof input === 'object' && input !== null
}
/**
* Returns true if the input value is defined.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isDefined (input) {
return typeof input !== 'undefined'
}
/**
* Returns true if the input value is undefined.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isUndefined (input) {
return !isDefined(input)
}
/**
* Returns true if the input value is null.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isNull (input) {
return input === null
}
/**
* Returns true if the input value is not one of `undefined`, `null`, or `NaN`.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isDefinedValue (input) {
return isDefined(input) && !isNull(input) && !Number.isNaN(input)
}
/**
* Returns true if the input value is an ES2015 `class`.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isClass (input) {
if (typeof input === 'function') {
return /^class /.test(Function.prototype.toString.call(input))
} else {
return false
}
}
/**
* Returns true if the input is a string, number, symbol, boolean, null or undefined value.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isPrimitive (input) {
if (input === null) return true
switch (typeof input) {
case 'string':
case 'number':
case 'symbol':
case 'undefined':
case 'boolean':
return true
default:
return false
}
}
/**
* Returns true if the input is a Promise.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isPromise (input) {
if (input) {
const isPromise = isDefined(Promise) && input instanceof Promise
const isThenable = input.then && typeof input.then === 'function'
return !!(isPromise || isThenable)
} else {
return false
}
}
/**
* Returns true if the input is an iterable (`Map`, `Set`, `Array`, Generator etc.).
* @param {*} - the input to test
* @returns {boolean}
* @static
* @example
* > t.isIterable('string')
* true
* > t.isIterable(new Map())
* true
* > t.isIterable([])
* true
* > t.isIterable((function * () {})())
* true
* > t.isIterable(Promise.resolve())
* false
* > t.isIterable(Promise)
* false
* > t.isIterable(true)
* false
* > t.isIterable({})
* false
* > t.isIterable(0)
* false
* > t.isIterable(1.1)
* false
* > t.isIterable(NaN)
* false
* > t.isIterable(Infinity)
* false
* > t.isIterable(function () {})
* false
* > t.isIterable(Date)
* false
* > t.isIterable()
* false
* > t.isIterable({ then: function () {} })
* false
*/
export function isIterable (input) {
if (input === null || !isDefined(input)) {
return false
} else {
return (
typeof input[Symbol.iterator] === 'function' ||
typeof input[Symbol.asyncIterator] === 'function'
)
}
}
/**
* Returns true if the input value is a string. The equivalent of `typeof input === 'string'` for use in funcitonal contexts.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isString (input) {
return typeof input === 'string'
}
/**
* Returns true if the input value is a function. The equivalent of `typeof input === 'function'` for use in funcitonal contexts.
* @param {*} - the input to test
* @returns {boolean}
* @static
*/
export function isFunction (input) {
return typeof input === 'function'
}
export default {
isNumber,
isPlainObject,
isArrayLike,
isObject,
isDefined,
isUndefined,
isNull,
isDefinedValue,
isClass,
isPrimitive,
isPromise,
isIterable,
isString,
isFunction
}