General utilities and helpers for composing, manipulating, and validating types in TypeScript. Includes helpers for improving readability, creating literal unions, excluding types, working with primitive values, and more.

utils

Installation

npm i -D @halvaradop/ts-utility-types

Usage

import type { Prettify, LiteralUnion, ReturnTypeOf } from "@halvaradop/ts-utility-types/utils"

import type * as Utils from "@halvaradop/ts-utility-types/utils" 


type Utilities = Utils.ArgsFunction
Discard
Falsy
LiteralUnion
Nullish
Prettify
Primitive
PrimitiveNullish
ReturnTypeOf
WhiteSpaces

`Prettify<Obj, object>`

Improves the readability of an object type by expanding its properties on separate lines. Does not modify the original type.

Argument	Type	Description
`Obj`	object	The object type to prettify.

import type { Prettify } from "@halvaradop/ts-utility-types/utils"

type Pretty = Prettify<{ foo: string; bar: number }>
      
type Pretty = {
    foo: string;
    bar: number;
}

`LiteralUnion<T, U = string>`

Extends the values of a literal type with a broader type (defaults to string).

Argument	Type	Description
`T`	U	The literal type(s) to extend.
`U`	string	The base type to extend with (default string).

import type { LiteralUnion } from "@halvaradop/ts-utility-types/utils"

type ExtendedFoo = LiteralUnion<"foo" | "bar">
        
type ExtendedFoo = "foo" | "bar" | (string & Record<never, never>)

`Discard<Type, Extends, Value = never, Reverse = false>`

Includes or excludes types based on assignability to another type. If Reverse is true, includes matching types; if false, excludes them.

Argument	Type	Description
`Type`	any	The union type to filter.
`Extends`	any	The type to check assignability against.
`Value`	any	The value to use for excluded/included types (default never).
`Reverse`	boolean	If true, includes matching types; if false, excludes them (default false).

import type { Discard } from "@halvaradop/ts-utility-types/utils"

type A = Discard<string | number, string>   
type A = number

type B = Discard<string | number, boolean>
   
type B = string | number

`ArgsFunction`

Represents a function that accepts any number of arguments of any type.

import type { ArgsFunction } from "@halvaradop/ts-utility-types/utils"

const fn: ArgsFunction = (...args) => {}
     
const fn: ArgsFunction

`Nullish`

Represents the absence of value: null or undefined.

import type { Nullish } from "@halvaradop/ts-utility-types/utils"

type CanBeNull = string | Nullish
       
type CanBeNull = string | Nullish

`PrimitiveNullish`

A primitive type that can also be null or undefined.

import type { PrimitiveNullish } from "@halvaradop/ts-utility-types/utils"

type PrimitiveOrNull = PrimitiveNullish
          
type PrimitiveOrNull = string | number | bigint | boolean | symbol | Nullish

`Primitive`

A primitive type: number, string, boolean, bigint, or symbol (excludes nullish).

import type { Primitive } from "@halvaradop/ts-utility-types/utils"

type PrimitiveValues = Primitive
          
type PrimitiveValues = {}

`WhiteSpaces`

Represents whitespace characters recognized by TypeScript.

import type { WhiteSpaces } from "@halvaradop/ts-utility-types/utils"

type Spaces = WhiteSpaces
      
type Spaces = " " | "\n" | "\t" | "\r" | "\f" | "\v" | " " | " " | " " | " " | " " | " " | " " | " " | " " | " " | " " | " " | " " | "\u2028" | "\u2029" | " " | " " | "　"

`Falsy`

Represents falsy values: null, undefined, 0, false, or "".

import type { Falsy } from "@halvaradop/ts-utility-types/utils"

type FalsyValue = Falsy
        
type FalsyValue = false | "" | 0 | Nullish

`ReturnTypeOf<T>`

Determines the primitive type corresponding to the provided value.

Argument	Type	Description
`T`	any	The value to get the primitive type of.

import type { ReturnTypeOf } from "@halvaradop/ts-utility-types/utils"

type TypeOfValue = ReturnTypeOf<123>        
type TypeOfValue = number

type TypeOfValueString = ReturnTypeOf<"hello">           
type TypeOfValueString = string

type TypeOfValueBool = ReturnTypeOf<true>          
type TypeOfValueBool = boolean

type TypeOfValueArr = ReturnTypeOf<[1, 2, 3]>
          
type TypeOfValueArr = [1, 2, 3]

General Utils