openinf / openinf-util-types

Fundamental JavaScript type-related utilities

@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)

---

Table of Contents

• Installation
• Usage
• API
• Contributing
• License

---

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.

---

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.

---

Show Your Support

If you like the project (or want to bookmark it) —
— give it a star ⭐️ — it will greatly encourage us.

openinf-util-types's Issues

build: remove build products from repo & migrate to babel for transpilation

It is preferable not to check the compiled typescript into our repo — let's remove that javascript from here. Additionally, we should use babel for this transpilation instead of the typescript compiler. We will, however, continue using tsc for type checking and type definition generation.

doc: record package naming considerations wrt excessive broadness

This package allows for excessive broadness in scope and am having trouble coming up w/ what should be stated in this repo's VISION file. It may likely be the case that the naming can be improved to be focused.

See: typescript-eslint/typescript-eslint#4172

[feature request] add new `isNullish` predicate function

Checks whether something is null or undefined.

Would be useful for OpenINF/openinf-util-object#133. We can have it out in the next minor…

Can this be achieved solely using Nullish coalescing? Maybe in the TS, but now wondering what ES year we are searching for compatibility with since this is a relatively new language feature.

Refs: https://devblogs.microsoft.com/typescript/announcing-typescript-4-8/#improved-intersection-reduction-union-compatibility-and-narrowing

/cc @septs @ignoreintuition

`isModuleNamespaceObject` could be better tested

I think the @masknet/compartment package exposes the Module constructor that we would be able to use to test our isModuleNamespaceObject function against.

Maybe i am confused tho.

/cc @septs @jackworks

[feature request] prevent including unnecessary files in the deployed package

We should consider adding the "files" stanza to the package.json to create an explicit allowlist and prevent deploying any unnecessary files to the npm registry as part of our package. This would be preferable to using a .npmignore file, which we have been doing so far but is expected to quickly become unmanageable as more files are added.

[bug] set of control abastraction objects is incomplete

We are currently missing a couple of control abstraction object predicates from this library. This was in part due to there not being any documentation associated with them on MDN at the time when we published our initial round of package versions. Since then, along with a few of the good folks over at that project, I've gone ahead and wrote them up and we've gotten the missing pages added to the official JavaScript documentation.

Control abstractions can help to structure code, especially async code (without using deeply nested callbacks, for example).

• Promise: isPromise
• Generator: isGeneratorObject
• GeneratorFunction: isGeneratorFunction
• AsyncFunction: isAsyncFunction
• AsyncGenerator: isAsyncGeneratorObject
• AsyncGeneratorFunction: isAsyncGeneratorFunction

(JS-0321) Detected empty functions

Description

Empty functions can reduce readability because readers need to guess whether it's intentional or not. So writing a clear comment for empty functions is a good practice.

Occurrences

There are 10 occurrences of this issue in the repository.

See all occurrences on DeepSource → deepsource.io/gh/openinf/util-types/issue/JS-0321/occurrences/

[feature request] DeepScan to use ESLint over built-in rules

DeepScan has been configured to check for ESLint config instead of using its default rules. This means that it will be ready for us once ESLint is good to go here.

You've analyzed the project with ESLint, but the ESLint analysis failed by the ESLint error.

After checking the details of error and configuring ESLint correctly, please reanalyze this project.

ESLint couldn't find a configuration file. To set up a configuration file for this project, please run:

eslint --init

[testing] code coverage reporting & test data artifact uploading

[…] only the Cobertura XML format is supported by DeepSource

— https://deepsource.io/docs/analyzer/test-coverage/#javascript

Currently, our tests in this repo are written using tape, yet we are instructed to use Jest to generate the coverage reports… As long as the output is in the expected Cobertura XML format, i think we should be alright, but was unable to find an option for that output using tape nor were there any suitable companion modules altho tap-nyc would seem to be what we are looking for if it would output XML. 😕

We could also use node-tap instead of tape and use its --coverage-report=cobertura flag. I was hoping not to do much refactoring to get this working correctly, but if that is not the case, I have no objection to moving to a more elegant solution if necessary. We seem to have outgrown both tape and tap, but I am also not a huge fan of Jest…

Refs: https://node-tap.org/docs/coverage/#uploading-coverage-to-other-services

Hacktoberfest checklist: prepare project for contributions by following best practices

• Add the “hacktoberfest” topic to your repository to opt-in to Hacktoberfest and indicate you’re looking for contributions.

• Apply the “hacktoberfest” label to issues you want contributors to help within your GitHub or GitLab project.

• Add a CONTRIBUTING.md file with contribution guidelines to your repository.

• Choose issues that have a well-defined scope and are self-contained.

• Adopt a code of conduct to create a greater sense of inclusion and community for contributors.

• Be ready to review pull/merge requests, accepting those that are valid by merging them, leaving an overall approving review, or by adding the “hacktoberfest-accepted” label.

• Reject any spammy requests you receive by labeling them as “spam”, and any other invalid contributions by closing them or labeling them as “invalid”.

Refs: https://hacktoberfest.com/participation/#maintainers

Dependency Dashboard

This issue lists Renovate updates and detected dependencies. Read the Dependency Dashboard docs to learn more.

Open

These updates have all been created already. Click a checkbox below to force a retry/rebase of any.

• build(deps-dev): bump @types/jsdom to v21.1.7
• build(deps-dev): bump typescript to v5.4.5
• chore(deps): bump pnpm to v8.15.8
• build(deps-dev): bump jsdom to v24
• chore(deps): bump actions/checkout action to v4
• chore(deps): bump github/codeql-action action to v3
• chore(deps): bump pnpm to v9
• chore(deps): bump ubuntu to v22
• Click on this checkbox to rebase all open PRs at once

Detected dependencies

github-actions

.github/workflows/codeql-analysis.yml

• actions/checkout v3
• github/codeql-action v2
• github/codeql-action v2
• github/codeql-action v2

.github/workflows/semgrep.yml

• actions/checkout v3
• ubuntu 20.04

npm

package.json

• @types/jsdom 21.1.1
• @types/node 20.x.x
• jsdom 22.1.0
• typescript 5.1.3
• pnpm 8.6.3

nvm

.nvmrc

• node 20

---

• Check this box to trigger a request for Renovate to run again on this repository