Complete type checking for Node

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

npm install is-type-of

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);
  }
}

Returns true if val is string, not String object.

See Also is.string

Returns true if val is number, not Number object.

See Also is.number

Returns true if val is boolean, not Boolean object.

See Also is.boolean

Returns true if val is bigint.

See Also is.bigInt

Returns true if val is symbol.

See Also is.symbol

Returns true if val is undefined.

See Also is.undefined

Returns true if val is null.

See Also is.null

Returns true if val is null or undefined.

See Also is.nullable

Returns true if val is primitive.

See Also is.primitive

Returns true if val is integer.

See Also is.integer

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

See Also is.integer32

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

See Also is.long

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

See Also is.safeInteger

Returns true if val is Double.

See Also is.double

Returns true if val is NaN.

See Also is.NaN

Returns true if val is finite.

See Also is.finite

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

See Also is.array

Returns true if val is function.

See Also is.function

Returns true if val is generator function.

See Also is.generatorFunction

Returns true if val is async function.

See Also is.asyncFunction

Returns true if val is async generator function.

See Also is.asyncGeneratorFunction

Returns true if val is object.

See Also is.object

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

Returns true if val is regular expression.

See Also is.regExp

Returns true if val is instance of Date.

See Also is.date

Returns true if val is instance of Error.

See Also is.error

Returns true if val is generator.

See Also is.generator

Returns true if val is promise.

See Also is.promise

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

See Also is.promiseLike

Returns true if val is buffer.

See Also is.buffer

Returns true if val is stream.

See Also is.stream

Returns true if val is readable stream.

See Also is.readable

Returns true if val is write stream.

See Also is.writable

Returns true if val is duplex stream.

See Also is.duplex

returns true if val is LongObject

LongObject is from npm package long

See Also is.longObject

• core-util-is
• is-stream
• is-class

MIT

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