is-type-of

Complete type checking for Node

Features

• 🔒 Useful Type Checking，including Primitive, Standard Object, Node Object
• ✨ Typescript Support
• 🚪 Typescript Type Guard Support

Install

npm install is-type-of

Usage

Use ES Module import

import is from 'is-type-of';
import { isArray } from 'is-type-of';

isArray([]); // => true
is.array([]); // => true

Compatible With

const is = require('is-type-of');

is.array([1]); // => true
is.primitive(true); // => true
is.primitive({}); // => false
is.generatorFunction(function * () {}); // => true
is.long(Math.pow(2, 33)); // => true
is.double(0); // => false

Use Type Guard

import { isArray } from 'is-type-of';

function checkArray(arr: string[] | string) {
  // => parameter) arr: string | string[]
  if (isArray(arr)) {
    // => (parameter) arr: string[]
    arr.forEach(console.log);
  }
}

API Document

Primitive

isString

Returns true if val is string, not String object.

See Also is.string

isNumber

Returns true if val is number, not Number object.

See Also is.number

isBoolean

Returns true if val is boolean, not Boolean object.

See Also is.boolean

isBigInt

Returns true if val is bigint.

See Also is.bigInt

isSymbol

Returns true if val is symbol.

See Also is.symbol

isUndefined

Returns true if val is undefined.

See Also is.undefined

isNull

Returns true if val is null.

See Also is.null

isNullable

Returns true if val is null or undefined.

See Also is.nullable

isPrimitive

Returns true if val is primitive.

See Also is.primitive

isInteger

Returns true if val is integer.

See Also is.integer

isInteger32

Returns true if val is integer, and between -2 ** 31 and 2 ** 31 - 1.

See Also is.integer32

isLong

Returns true if val is integer, and < -2 ** 31, and > 2 ** 31 - 1.

See Also is.long

isSafeInteger

Returns true if val is integer, and between -(2 ** 53 - 1) and 2 ** 53 - 1.

See Also is.safeInteger

isDouble

Returns true if val is Double.

See Also is.double

isNaN

Returns true if val is NaN.

See Also is.NaN

isFinite

Returns true if val is finite.

See Also is.finite

Standard Object

API Documentation

isArray

Returns true if val is array, it won't check items of array.

See Also is.array

isFunction

Returns true if val is function.

See Also is.function

isGeneratorFunction

Returns true if val is generator function.

See Also is.generatorFunction

isAsyncFunction

Returns true if val is async function.

See Also is.asyncFunction

isAsyncGeneratorFunction

Returns true if val is async generator function.

See Also is.asyncGeneratorFunction

isObject

Returns true if val is object.

See Also is.object

isClass

Returns true if val is class.

Note: "class" is supported in ECMAScript 6, and if the code is using some compiler or transpiler, the checking might fail.

See Also is.class

isRegExp

Returns true if val is regular expression.

See Also is.regExp

isDate

Returns true if val is instance of Date.

See Also is.date

isError

Returns true if val is instance of Error.

See Also is.error

isGenerator

Returns true if val is generator.

See Also is.generator

isPromise

Returns true if val is promise.

See Also is.promise

isPromiseLike

Returns true if val is like promise, if the object has then property, the checking will pass.

See Also is.promiseLike

Node Object

isBuffer

Returns true if val is buffer.

See Also is.buffer

isStream

Returns true if val is stream.

See Also is.stream

isReadable

Returns true if val is readable stream.

See Also is.readable

isWritable

Returns true if val is write stream.

See Also is.writable

isDuplex

Returns true if val is duplex stream.

See Also is.duplex

External Object

isLongObject

returns true if val is LongObject

LongObject is from npm package long

See Also is.longObject

Thanks

• core-util-is
• is-stream
• is-class

License

MIT