@openinf/util-types

Fundamental JavaScript type-related utilities

The high-level goal of @openinf/util-types is to serve as a Node.js package containing utilities for fundamental JavaScript type-related operations primarily enabling users to perform native typechecking and simplify type coercion. We are constantly working to improve this repository, so please feel free to contribute if you notice any omissions or errors.

Thanks!

Supported Node.js Environments

• v4：Argon (Ar)
• v6：Boron (B)
• v8：Carbon (C)
• v10：Dubnium (Db)
• v12：Erbium (Er)
• v14：Fermium (Fm)
• v16：Gallium (Ga)
• v18：Hydrogen (H)

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Table of Contents

• Installation
• Usage
• API
• Contributing
• License

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Installation

@openinf/util-types runs on supported versions of Node.js and is available via npm, pnpm, or yarn.

Using the npm CLI

^{See the official documentation for this command for more information.}

npm i @openinf/util-types

Using the pnpm CLI

^{See the official documentation for this command for more information.}

pnpm add @openinf/util-types

Using the Yarn 1 CLI (Classic)

^{See the official documentation for this command for more information.}

yarn add @openinf/util-types

Usage

Import the helper functions based on your platform.

import { isObject } from '@openinf/util-types';

const maybeObject = null;

if (isObject(maybeObject)) {
  console.log('The value of `maybeObject` is of type Object.');
} else {
  console.log('The value of `maybeObject` is not of type Object.');
}

API

toString(value) ⇒ string

Returns the ECMAScript [[Class]] internal property of the passed value.

isUndefined(value) ⇒ boolean

Determines whether the passed value is actually of type undefined.

isObject(value) ⇒ boolean

Determines whether the passed value is of type Object.

isOrdinaryFunction(value) ⇒ boolean

Determines whether the passed value is of type Function.

isBooleanObject(value) ⇒ boolean

Determines whether the passed value is actually a Boolean object.

isSymbolObject(value) ⇒ boolean

Determines whether the passed value is actually a Symbol object.

isNativeError(value) ⇒ boolean

Determines whether the passed value is one of the native error types:

• EvalError
• RangeError
• ReferenceError
• SyntaxError
• TypeError
• URIError
• AggregateError
• InternalError

isNumberObject(value) ⇒ boolean

Determines whether the passed value is actually a Number object (boxed primitive).

isBigIntObject(value) ⇒ boolean

Determines whether the passed value is actually a BigInt object (boxed primitive).

isFiniteNumber(value) ⇒ boolean

Determines whether the passed value is of number type and finite. NaN and Infinity are not considered a finite number. String numbers are not considered numbers.

isMath(value) ⇒ boolean

Determines whether the passed value is actually the Math global object.

isDate(value) ⇒ boolean

Determines whether the passed value is of type Date.

isStringObject(value) ⇒ boolean

Determines whether the passed value is actually a String object.

isRegExp(value) ⇒ boolean

Determines whether the passed value is of type RegExp.

isArray(value) ⇒ boolean

Determines whether the passed value is of type Array.

toArray(arrayLike) ⇒ Array<T>

Converts an array-like object to an array.

isInt8Array(value) ⇒ boolean

Determines whether the passed value is of type Int8Array.

isUint8Array(value) ⇒ boolean

Determines whether the passed value is of type Uint8Array.

isUint8ClampedArray(value) ⇒ boolean

Determines whether the passed value is of type Uint8ClampedArray.

isInt16Array(value) ⇒ boolean

Determines whether the passed value is of type Int16Array.

isUint16Array(value) ⇒ boolean

Determines whether the passed value is of type Uint16Array.

isInt32Array(value) ⇒ boolean

Determines whether the passed value is of type Int32Array.

isUint32Array(value) ⇒ boolean

Determines whether the passed value is of type Uint32Array.

isFloat32Array(value) ⇒ boolean

Determines whether the passed value is of type Float32Array.

isFloat64Array(value) ⇒ boolean

Determines whether the passed value is of type Float64Array.

isBigInt64Array(value) ⇒ boolean

Determines whether the passed value is of type BigInt64Array.

isBigUint64Array(value) ⇒ boolean

Determines whether the passed value is of type BigUint64Array.

isArrayBufferView(value) ⇒ boolean

Determines whether the passed value is an ArrayBufferView, which is a helper type representing any of the following JavaScript TypedArray types:

• Int8Array
• Uint8Array
• Uint8ClampedArray
• Int16Array
• Uint16Array
• Int32Array
• Uint32Array
• Float32Array
• Float64Array
• DataView

isTypedArray(value) ⇒ boolean

Determines if value is one of the TypedArray element types:

• Int8Array
• Uint8Array
• Uint8ClampedArray
• Int16Array
• Uint16Array
• Int32Array
• Uint32Array
• Float32Array
• Float64Array
• BigInt64Array
• BigUint64Array

isMap(value) ⇒ boolean

Determines whether the passed value is of type Map.

isMapIterator(value) ⇒ boolean

Determines whether the passed value is of type Map Iterator.

isSet(value) ⇒ boolean

Determines whether the passed value is of type Set.

isSetIterator(value) ⇒ boolean

Determines whether the passed value is of type Set Iterator.

isWeakMap(value) ⇒ boolean

Determines whether the passed value is of type WeakMap.

isWeakSet(value) ⇒ boolean

Determines whether the passed value is of type WeakSet.

isArrayBuffer(value) ⇒ boolean

Determines whether the passed value is of type ArrayBuffer.

isSharedArrayBuffer(value) ⇒ boolean

Determines whether the passed value is of type SharedArrayBuffer.

isAnyArrayBuffer(value) ⇒ boolean

Determines whether the passed value is one of either ArrayBuffer or SharedArrayBuffer.

isDataView(value) ⇒ boolean

Determines whether the passed value is of type DataView.

isPromise(value) ⇒ boolean

Determines whether the passed value is of type Promise.

isGeneratorObject(value) ⇒ boolean

Determines whether the passed value is actually a Generator object.

isGeneratorFunction(value) ⇒ boolean

Determines whether the passed value is of type GeneratorFunction.

isAsyncFunction(value) ⇒ boolean

Determines whether the passed value is of type AsyncFunction.

isArgumentsObject(value) ⇒ boolean

Determines whether the passed value is actually an arguments object.

isBoxedPrimitive(value) ⇒ boolean

Determines whether the passed value is a primitive wrapped by its object equivalent (a.k.a. "boxed"). Except for null and undefined, all primitive values have object equivalents that wrap around the primitive values:

• Boolean
• String
• Number
• Symbol
• BigInt

isModuleNamespaceObject(value) ⇒ boolean

Determines whether the passed value is a Module namespace object.

isPrimitive(value) ⇒ boolean

Determines whether the passed value is of a primitive data type.

toString(value) ⇒ string

Returns the ECMAScript [[Class]] internal property of the passed value.

Kind: global function
Returns: string - A specification-defined classification of objects.

Param	Type	Description
value	unknown	The value to be checked.

isUndefined(value) ⇒ boolean

Determines whether the passed value is actually of type undefined.

Kind: global function
Returns: boolean - true if the value is undefined; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isObject(value) ⇒ boolean

Determines whether the passed value is of type Object.

Kind: global function
Returns: boolean - true if the value is an Object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isOrdinaryFunction(value) ⇒ boolean

Determines whether the passed value is of type Function.

Kind: global function
Returns: boolean - true if the value is a Function; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isBooleanObject(value) ⇒ boolean

Determines whether the passed value is actually a Boolean object.

Kind: global function
Returns: boolean - true if the value is a Boolean object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isSymbolObject(value) ⇒ boolean

Determines whether the passed value is actually a Symbol object.

Kind: global function
Returns: boolean - true if the value is a Symbol object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isNativeError(value) ⇒ boolean

Determines whether the passed value is one of the native error types:

• EvalError
• RangeError
• ReferenceError
• SyntaxError
• TypeError
• URIError
• AggregateError
• InternalError

Kind: global function
Returns: boolean - true if the value is a native error; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isNumberObject(value) ⇒ boolean

Determines whether the passed value is actually a Number object (boxed primitive).

Kind: global function
Returns: boolean - true if the value is a Number object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isBigIntObject(value) ⇒ boolean

Determines whether the passed value is actually a BigInt object (boxed primitive).

Kind: global function
Returns: boolean - true if the value is a BigInt object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isFiniteNumber(value) ⇒ boolean

Determines whether the passed value is of number type and finite. NaN and Infinity are not considered a finite number. String numbers are not considered numbers.

Kind: global function
Returns: boolean - true if the value is a finite number; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isMath(value) ⇒ boolean

Determines whether the passed value is actually the Math global object.

Kind: global function
Returns: boolean - true if the value is the Math object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isDate(value) ⇒ boolean

Determines whether the passed value is of type Date.

Kind: global function
Returns: boolean - true if the value is a Date; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isStringObject(value) ⇒ boolean

Determines whether the passed value is actually a String object.

Kind: global function
Returns: boolean - true if the value is a String object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isRegExp(value) ⇒ boolean

Determines whether the passed value is of type RegExp.

Kind: global function
Returns: boolean - true if the value is a RegExp; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isArray(value) ⇒ boolean

Determines whether the passed value is of type Array.

Kind: global function
Returns: boolean - true if the value is an Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

toArray(arrayLike) ⇒ Array<T>

Converts an array-like object to an array.

Kind: global function

Param	Type
arrayLike	ArrayLike<T> | string

isInt8Array(value) ⇒ boolean

Determines whether the passed value is of type Int8Array.

Kind: global function
Returns: boolean - true if the value is an Int8Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isUint8Array(value) ⇒ boolean

Determines whether the passed value is of type Uint8Array.

Kind: global function
Returns: boolean - true if the value is a Uint8Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isUint8ClampedArray(value) ⇒ boolean

Determines whether the passed value is of type Uint8ClampedArray.

Kind: global function
Returns: boolean - true if the value is a Uint8ClampedArray; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isInt16Array(value) ⇒ boolean

Determines whether the passed value is of type Int16Array.

Kind: global function
Returns: boolean - true if the value is an Int16Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isUint16Array(value) ⇒ boolean

Determines whether the passed value is of type Uint16Array.

Kind: global function
Returns: boolean - true if the value is a Uint16Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isInt32Array(value) ⇒ boolean

Determines whether the passed value is of type Int32Array.

Kind: global function
Returns: boolean - true if the value is an Int32Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isUint32Array(value) ⇒ boolean

Determines whether the passed value is of type Uint32Array.

Kind: global function
Returns: boolean - true if the value is a Uint32Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isFloat32Array(value) ⇒ boolean

Determines whether the passed value is of type Float32Array.

Kind: global function
Returns: boolean - true if the value is a Float32Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isFloat64Array(value) ⇒ boolean

Determines whether the passed value is of type Float64Array.

Kind: global function
Returns: boolean - true if the value is a Float64Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isBigInt64Array(value) ⇒ boolean

Determines whether the passed value is of type BigInt64Array.

Kind: global function
Returns: boolean - true if the value is a BigInt64Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isBigUint64Array(value) ⇒ boolean

Determines whether the passed value is of type BigUint64Array.

Kind: global function
Returns: boolean - true if the value is a BigUint64Array; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isArrayBufferView(value) ⇒ boolean

Determines whether the passed value is an ArrayBufferView, which is a helper type representing any of the following JavaScript TypedArray types:

• Int8Array
• Uint8Array
• Uint8ClampedArray
• Int16Array
• Uint16Array
• Int32Array
• Uint32Array
• Float32Array
• Float64Array
• DataView

Kind: global function
Returns: boolean - true if the value is an ArrayBufferView; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isTypedArray(value) ⇒ boolean

Determines if value is one of the TypedArray element types:

• Int8Array
• Uint8Array
• Uint8ClampedArray
• Int16Array
• Uint16Array
• Int32Array
• Uint32Array
• Float32Array
• Float64Array
• BigInt64Array
• BigUint64Array

Kind: global function
Returns: boolean - true if the value is one of the typed arrays; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isMap(value) ⇒ boolean

Determines whether the passed value is of type Map.

Kind: global function
Returns: boolean - true if the value is a Map; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isMapIterator(value) ⇒ boolean

Determines whether the passed value is of type Map Iterator.

Kind: global function
Returns: boolean - true if the value is a Map Iterator; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isSet(value) ⇒ boolean

Determines whether the passed value is of type Set.

Kind: global function
Returns: boolean - true if the value is a Set; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isSetIterator(value) ⇒ boolean

Determines whether the passed value is of type Set Iterator.

Kind: global function
Returns: boolean - true if the value is a Set Iterator; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isWeakMap(value) ⇒ boolean

Determines whether the passed value is of type WeakMap.

Kind: global function
Returns: boolean - true if the value is a WeakMap; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isWeakSet(value) ⇒ boolean

Determines whether the passed value is of type WeakSet.

Kind: global function
Returns: boolean - true if the value is a WeakSet; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isArrayBuffer(value) ⇒ boolean

Determines whether the passed value is of type ArrayBuffer.

Kind: global function
Returns: boolean - true if the value is an ArrayBuffer; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isSharedArrayBuffer(value) ⇒ boolean

Determines whether the passed value is of type SharedArrayBuffer.

Kind: global function
Returns: boolean - true if the value is a SharedArrayBuffer; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isAnyArrayBuffer(value) ⇒ boolean

Determines whether the passed value is one of either ArrayBuffer or SharedArrayBuffer.

Kind: global function
Returns: boolean - true if the value is one of the array buffers; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isDataView(value) ⇒ boolean

Determines whether the passed value is of type DataView.

Kind: global function
Returns: boolean - true if the value is a DataView; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isPromise(value) ⇒ boolean

Determines whether the passed value is of type Promise.

Kind: global function
Returns: boolean - true if the value is a Promise; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isGeneratorObject(value) ⇒ boolean

Determines whether the passed value is actually a Generator object.

Kind: global function
Returns: boolean - true if the value is a Generator; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isGeneratorFunction(value) ⇒ boolean

Determines whether the passed value is of type GeneratorFunction.

Kind: global function
Returns: boolean - true if the value is a GeneratorFunction; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isAsyncFunction(value) ⇒ boolean

Determines whether the passed value is of type AsyncFunction.

Kind: global function
Returns: boolean - true if the value is an AsyncFunction; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isArgumentsObject(value) ⇒ boolean

Determines whether the passed value is actually an arguments object.

Kind: global function
Returns: boolean - true if the value is an arguments object; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isBoxedPrimitive(value) ⇒ boolean

Determines whether the passed value is a primitive wrapped by its object equivalent (a.k.a. "boxed"). Except for null and undefined, all primitive values have object equivalents that wrap around the primitive values:

• Boolean
• String
• Number
• Symbol
• BigInt

Kind: global function
Returns: boolean - true if the value is one of the boxed primitives; otherwise, false.
See: https://developer.mozilla.org/en-US/docs/Glossary/Primitive#primitive_wrapper_objects_in_javascript

Param	Type	Description
value	unknown	The value to be checked.

isModuleNamespaceObject(value) ⇒ boolean

Determines whether the passed value is a Module namespace object.

Kind: global function
Returns: boolean - true if the value is a Module; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

isPrimitive(value) ⇒ boolean

Determines whether the passed value is of a primitive data type.

Kind: global function
Returns: boolean - true if the value is a primitive; otherwise, false.

Param	Type	Description
value	unknown	The value to be checked.

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Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change. If for whatever reason you spot something to fix but cannot patch it yourself, please open an issue.

License

This project is licensed under either of

• Apache License, Version 2.0
• MIT license

at your option.

The SPDX license identifier for this project is MIT OR Apache-2.0.

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