@wicle/is

JavaScript and TypeScript type testing library uniquely identifying types without overlap.

It does type testing for following types:

• Array
• Object
• Function: (a: unknown): a is Function =>
• String
• Number
• Date
• RegExp
• Error
• Symbol
• Map
• WeakMap
• Set
• WeakSet
• Class

If a variable is one of the above types, it means it is not of any other types above. For example, a variable is of type Function, then it is not of type Object. A class instance is of type Class, but not of type Object or Funciton, etc.

Installation

npm i --save-dev @wicle/is

# or
yard add -D @wicle/is

# or
pnpm add -D @wicle/is

Uagae

function (arg: any) {
    if (is.Function(arg)) {
        // ...
    }
    else if (is.Class(arg)) {
        //...
    }
    //...
}

API

• is.Array(arg)
• is.Object(arg)
• is.Function(arg): (a: unknown): a is Function =>
• is.String(arg)
• is.Number(arg)
• is.Date(arg)
• is.RegExp(arg)
• is.Error(arg)
• is.Symbol(arg)
• is.Map(arg)
• is.WeakMap(arg)
• is.Set(arg)
• is.WeakSet(arg)
• is.Class(arg)

Notes

Class type means Class definition. An instance of a Class is of type Object, not Class.

class classA { ... }
const instanceA = new classA()

is.Class(classA) --> true
is.Class(instanceA) --> flase
is.Object(instanceA) --> true