Node.js JavaScript Type checker (Primitives, Objects, etc..)
Package heavily inspired by @sindresorhus/is. This package aims to work on Node.js (no browser support).
- Focus on type checking (no fancy feature).
- Focus on Node.js support.
- Come with a TypeScript definition (which works).
- Is concerned about being stable.
- Node.js v16 or higher.
This package is available in the Node Package Repository and can be easily installed with npm or yarn.
$ npm i @slimio/is
# or
$ yarn add @slimio/isconst { strictEqual } = require("assert");
const is = require("@slimio/is");
strictEqual(is.bool(true), true);
strictEqual(is.string("hello"), true);
strictEqual(is.map(new Map()), true);
strictEqual(is.func(() => {}), true);The is const namespace is a Plain JavaScript Object with a lot of exported methods (check the below API Documentation).
All methods can be called as follow: is.{methodName}. All methods return a boolean value.
| method | example |
|---|---|
| string | is.string("hello") |
| number | is.number(10) |
| boolean | is.boolean(true) |
| bool | is.bool(false) |
| symbol | is.symbol(Symbol("foo")) |
| undefined | is.undefined(undefined) |
| bigint | is.bigint(50n) |
| nullValue | is.nullValue(null) |
| nullOrUndefined | is.nullOrUndefined(null) |
| primitive | is.primitive("hello") |
is.null is not available because of a name restriction.
| method | example |
|---|---|
| promise | is.promise(new Promise()) |
| classObject | is.classObject(new Class{}) |
| array | is.array([]) |
| object | is.object({}) |
| plainObject | is.plainObject(Object.create(null)) |
| set | is.set(new Set()) |
| map | is.map(new Map()) |
| weakMap | is.weakMap(new WeakMap()) |
| weakSet | is.weakSet(new WeakSet()) |
| error | is.error(new Error("ooppss!")) |
| date | is.date(new Date()) |
| regExp | is.regExp(/^hello world$/) |
| buffer | is.buffer(Buffer.from("hello")) |
is.class is not available because of a name restriction.
| method | example |
|---|---|
| func | is.func(new Function()) |
| generatorFunction | N/A |
| asyncFunction | is.asyncFunction(async function() {}) |
| boundFunction | is.boundFunction((function(){}).bind(null)) |
| iterable | is.iterable([1, 2]) |
| asyncIterable | N/A |
| generator | N/A |
is.function has been reduced to is.func because of a name restriction.
| method | example |
|---|---|
| typedArray | is.typedArray(new int8Array()) |
| int8Array | is.int8Array(new int8Array()) |
| uint8Array | is.uint8Array(new uint8Array()) |
| uint8ClampedArray | is.uint8ClampedArray(new uint8ClampedArray()) |
| int16Array | is.int16Array(new int16Array()) |
| uint16Array | is.uint16Array(new uint16Array()) |
| int32Array | is.int32Array(new int32Array()) |
| uint32Array | is.uint32Array(new uint32Array()) |
| float32Array | is.float32Array(new float32Array()) |
| float64Array | is.float64Array(new float64Array()) |
| arrayBuffer | is.arrayBuffer(new ArrayBuffer()) |
| sharedArrayBuffer | is.sharedArrayBuffer(new SharedArrayBuffer()) |
| dataView | is.dataView(new DataView(new ArrayBuffer(8))) |
| method | example |
|---|---|
| nan | is.nan(Number("booom!")) |
| integer | is.integer(5 / 10) |
| directInstanceOf | is.directInstanceOf(Object, {}) |
| truthy | is.truthy(true) |
| falsy | is.falsy("") |
| emptyString | is.emptyString("") |
This project have no dependencies.
MIT