@veloss/assertion

데이터에 대한 타입을 검증하고 검증된 데이터를 안전한 타입으로 변환하는 라이브러리입니다.

Usage

Install:

# npm
npm install @veloss/assertion

# yarn
yarn add @veloss/assertion

# pnpm
pnpm add @veloss/assertion

Import:

// ESM / Typescript
import { isNumber, ... } from "@veloss/assertion";

// CommonJS
const { isNumber, ... } = require("@veloss/assertion");

isNumber

Type: (value: any) => value is number

validate if the value is a number.

function isNumber(value: any): value is number;

Example

import { isNumber } from "@veloss/assertion";

console.log(isNumber(1)); // true
console.log(isNumber("1")); // false

isNotNumber

Type: (value: any) => value is null | undefined | string | boolean | object | any[]

validate if the value is not a number.

function isNotNumber(
  value: any
): value is null | undefined | string | boolean | object | any[];

Example

import { isNotNumber } from "@veloss/assertion";

console.log(isNotNumber(1)); // false
console.log(isNotNumber("1")); // true

isNumeric

Type: (value: any) => boolean

validate if the value is a numeric value.

function isNumeric(value: any): boolean;

Example

import { isNumeric } from "@veloss/assertion";

console.log(isNumeric(1)); // true
console.log(isNumeric("1")); // true
console.log(isNumeric("1.1")); // true
console.log(isNumeric("1.1.1")); // false

isInteger

Type: (value: any) => value is number

validate if the value is an integer.

function isInteger(value: any): value is number;

Example

import { isInteger } from "@veloss/assertion";

console.log(isInteger(1)); // true
console.log(isInteger(1.1)); // false

isFloat

Type: (value: any) => value is number

validate if the value is a float.

function isFloat(value: any): value is number;

Example

import { isFloat } from "@veloss/assertion";

console.log(isFloat(1.1)); // true
console.log(isFloat(1)); // false

isArray

Type: <T>(value: any) => value is T[]

validate if the value is an array.

function isArray<T>(value: any): value is T[];

Example

import { isArray } from "@veloss/assertion";

console.log(isArray([1, 2, 3])); // true
console.log(isArray("1,2,3".split(","))); // true

isEmptyArray

Type: (value: any) => value is []

validate if the value is an empty array.

function isEmptyArray(value: any): value is [];

Example

import { isEmptyArray } from "@veloss/assertion";

console.log(isEmptyArray([])); // true
console.log(isEmptyArray([1, 2, 3])); // false

isFunction

Type: <T extends AnyFunction = AnyFunction>(value: any) => value is T

validate if the value is a function.

function isFunction<T extends AnyFunction = AnyFunction>(
  value: any
): value is T;

Example

import { isFunction } from "@veloss/assertion";

console.log(isFunction(() => {})); // true
console.log(isFunction(function () {})); // true

isDefined

Type: <T>(value: T) => value is NonNullable<T>

validate if the value is defined.

function isDefined<T>(value: T): value is NonNullable<T>;

Example

import { isDefined } from "@veloss/assertion";

console.log(isDefined(1)); // true
console.log(isDefined(null)); // false

isUndefined

Type: (value: any) => value is undefined

validate if the value is undefined.

function isUndefined(value: any): value is undefined;

Example

import { isUndefined } from "@veloss/assertion";

console.log(isUndefined(undefined)); // true
console.log(isUndefined(null)); // false

isNull

Type: (value: any) => value is null

validate if the value is null.

function isNull(value: any): value is null;

Example

import { isNull } from "@veloss/assertion";

console.log(isNull(null)); // true
console.log(isNull(undefined)); // false

isObject

Type: <T extends object = object>(value: any) => value is T

validate if the value is an object.

function isObject<T extends object = object>(value: any): value is T;

Example

import { isObject } from "@veloss/assertion";

console.log(isObject({})); // true
console.log(isObject([])); // false

isEmptyObject

Type: (value: any) => value is {}

validate if the value is an empty object.

function isEmptyObject(value: any): value is {};

Example

import { isEmptyObject } from "@veloss/assertion";

console.log(isEmptyObject({})); // true
console.log(isEmptyObject({ a: 1 })); // false

isNotEmptyObject

Type: (value: any) => value is object

validate if the value is not an empty object.

function isNotEmptyObject(value: any): value is object;

Example

import { isNotEmptyObject } from "@veloss/assertion";

console.log(isNotEmptyObject({})); // false
console.log(isNotEmptyObject({ a: 1 })); // true

isString

Type: (value: any) => value is string

validate if the value is a string.

function isString(value: any): value is string;

Example

import { isString } from "@veloss/assertion";

console.log(isString("")); // true
console.log(isString(1)); // false

isBoolean

Type: (value: any) => value is boolean

validate if the value is a boolean.

function isBoolean(value: any): value is boolean;

Example

import { isBoolean } from "@veloss/assertion";

console.log(isBoolean(true)); // true
console.log(isBoolean(1)); // false

isSymbol

Type: (value: any) => value is symbol

validate if the value is a symbol.

function isSymbol(value: any): value is symbol;

Example

import { isSymbol } from "@veloss/assertion";

console.log(isSymbol(Symbol())); // true
console.log(isSymbol(1)); // false

isDate

Type: (value: any) => value is Date

validate if the value is a date.

function isDate(value: any): value is Date;

Example

import { isDate } from "@veloss/assertion";

console.log(isDate(new Date())); // true
console.log(isDate(1)); // false

isEmpty

Type: (value: any) => boolean

validate if the value is empty.

function isEmpty(value: any): boolean;

Example

import { isEmpty } from "@veloss/assertion";

console.log(isEmpty("")); // true
console.log(isEmpty([])); // true
console.log(isEmpty({})); // true
console.log(isEmpty(null)); // true
console.log(isEmpty(undefined)); // true
console.log(isEmpty(0)); // false
console.log(isEmpty("1")); // false

isNullOrUndefined

Type: (value: any) => value is null | undefined

validate if the value is null or undefined.

function isNullOrUndefined(value: any): value is null | undefined;

Example

import { isNullOrUndefined } from "@veloss/assertion";

console.log(isNullOrUndefined(null)); // true
console.log(isNullOrUndefined(undefined)); // true
console.log(isNullOrUndefined(0)); // false

isBrowser

Type: () => boolean

validate if the code is running in a browser environment.

function isBrowser(): boolean;

Example

import { isBrowser } from "@veloss/assertion";

console.log(isBrowser()); // true

isNode

Type: () => boolean

validate if the code is running in a Node.js environment.

function isNode(): boolean;

Example

import { isNode } from "@veloss/assertion";

console.log(isNode()); // false

isFalsy

Type: (value: any) => value is false | null | undefined | 0 | ""

validate if the value is falsy.

function isFalsy(value: any): value is false | null | undefined | 0 | "";

Example

import { isFalsy } from "@veloss/assertion";

console.log(isFalsy(null)); // true
console.log(isFalsy(undefined)); // true
console.log(isFalsy(0)); // true
console.log(isFalsy("")); // true
console.log(isFalsy(1)); // false

isTruthy

Type: (value: any) => value is true

validate if the value is truthy.

function isTruthy(value: any): value is true;

Example

import { isTruthy } from "@veloss/assertion";

console.log(isTruthy(true)); // true
console.log(isTruthy(1)); // false

isPromiseLike

Type: <T = any>(value: any) => value is PromiseLike<T>

validate if the value is a promise-like object.

function isPromiseLike<T = any>(value: any): value is PromiseLike<T>;

Example

import { isPromiseLike } from "@veloss/assertion";

console.log(isPromiseLike(Promise.resolve())); // true
console.log(isPromiseLike({ then: () => {} })); // true

isPrimitive

Type: (value: any) => value is string | number | boolean | symbol | null | undefined

validate if the value is a primitive value.

function isPrimitive(
  value: any
): value is string | number | boolean | symbol | null | undefined;

Example

import { isPrimitive } from "@veloss/assertion";

console.log(isPrimitive("")); // true
console.log(isPrimitive(1)); // true
console.log(isPrimitive(true)); // true
console.log(isPrimitive(Symbol())); // true
console.log(isPrimitive(null)); // true
console.log(isPrimitive(undefined)); // true
console.log(isPrimitive({})); // false

💻 Development

• Clone this repository
• Enable Corepack using corepack enable (use npm i -g corepack for Node.js < 16.10)
• Install dependencies using pnpm install
• Run interactive tests using pnpm test
• Build the project using pnpm build
• format and lint the project using pnpm format and pnpm lint and pnpm typecheck

License

MIT