Utilities for type checks and validations in TypeScript. These types help compare, validate, and discriminate types at compile time, enabling advanced conditional types and type guards.

Type Guards

Utilities for type checks and validations in TypeScript. These types help compare, validate, and discriminate types at compile time, enabling advanced conditional types and type guards.

Installation

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

Usage

import type { Equals, IsNever, IsAny } from "@halvaradop/ts-utility-types/type-guards"

import type * as Guards from "@halvaradop/ts-utility-types/type-guards"


type Utilities = Guards.AnyOf
Equals
Expect
IsAny
IsArray
IsFunction
IsNever
IsObject
Not

`Equals<X, Y>`

Argument	Type	Description
`X`	`unknown`	The first type to compare.
`Y`	`unknown`	The second type to compare.

Checks if two types are strictly equal.

import type { Equals } from "@halvaradop/ts-utility-types/type-guards"

type CheckTrue = Equals<true, true>       
type CheckTrue = true

type CheckFalse = Equals<() => {}, true>
        
type CheckFalse = false

`Expect<T>`

Argument	Type	Description
`T`	`true`	The type to check for being true.

Ensures the received type is true. Useful for type-level tests.

import type { Expect } from "@halvaradop/ts-utility-types/type-guards"

type CheckTrue = Expect<true>       
type CheckTrue = true


type CheckFalse = Expect<false>Type 'false' does not satisfy the constraint 'true'.

`Not<T>`

Argument	Type	Description
`T`	`boolean`	The boolean type to negate.

Negates a boolean type value.

import type { Not } from "@halvaradop/ts-utility-types/type-guards"

type CheckFalse = Not<true>        
type CheckFalse = false

type CheckTrue = Not<false>
       
type CheckTrue = true

`IsNever<T>`

Argument	Type	Description
`T`	`unknown`	The type to check for never.

Checks if the type is never.

import type { IsNever } from "@halvaradop/ts-utility-types/type-guards"

type CheckNever = IsNever<never>        
type CheckNever = true

type CheckStr = IsNever<string>
       
type CheckStr = false

`IsAny<T>`

Argument	Type	Description
`T`	`unknown`	The type to check for any.

Checks if the type is any.

import type { IsAny } from "@halvaradop/ts-utility-types/type-guards"

type CheckAny = IsAny<any>       
type CheckAny = true

type CheckStr = IsAny<string>
       
type CheckStr = false

`AnyOf<T>`

Argument	Type	Description
`T`	`readonly any[]`	The tuple to check for any truthy value.

Checks if any value in the tuple is truthy.

import type { AnyOf } from "@halvaradop/ts-utility-types/type-guards"

type Test1 = AnyOf<[0, "", false, [], {}, undefined, null, true]>     
type Test1 = true

type Test2 = AnyOf<[0, "", false, [], {}, undefined, null]>
     
type Test2 = false

`IsArray<T>`

Checks if the type is an array.

Argument	Type	Description
`T`	`unknown`	The type to check for being an array.

import type { IsArray } from "@halvaradop/ts-utility-types/type-guards"

type Test1 = IsArray<[1, 2, 3]>     
type Test1 = true

type Test2 = IsArray<{ key: string }>
     
type Test2 = false

`IsObject<T>`

Checks if the type is an object (excluding arrays and functions).

Argument	Type	Description
`T`	`unknown`	The type to check for being an object.

import type { IsObject } from "@halvaradop/ts-utility-types/type-guards"

type Test1 = IsObject<{ key: string }>     
type Test1 = true

type Test2 = IsObject<[1, 2, 3]>
     
type Test2 = false

`IsFunction<T>`

Checks if the type is a function.

Argument	Type	Description
`T`	`unknown`	The type to check for being a function.

import type { IsFunction } from "@halvaradop/ts-utility-types/type-guards"

type Test1 = IsFunction<() => void>     
type Test1 = true

type Test2 = IsFunction<{ key: string }>
     
type Test2 = false

Type Guards

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