@hemjs/notions NPM

@hemjs/notions

Utilities for arrays, objects, strings, and more.

Installation

Install with npm:

npm install --save @hemjs/notions

Install with yarn:

yarn add @hemjs/notions

Async

`deadline`

Creates a promise which will be rejected with DeadlineError when a given delay is exceeded.

Type:

function deadline<T>(
  p: Promise<T>,
  ms: number,
  options?: DeadlineOptions,
): Promise<T>;

Example:

import { deadline } from '@hemjs/notions';

const myPromise = fetch('https://api.example.com/data');

deadline(myPromise, 1000) // Wait for 1 second
  .then((data) => {
    // Handle successful response
  })
  .catch((error) => {
    if (error instanceof DeadlineError) {
      console.error('Promise timed out!');
    } else {
      console.error('Error:', error);
    }
  });

Parameters:

p: The promise to be wrapped with a deadline.
ms: The delay in milliseconds before the deadline triggers.
options: (Optional) An object containing:
- signal: An AbortSignal object to manually abort the deadline.

Returns:

A new promise that resolves or rejects according to the original promise and the deadline.

Errors:

If the deadline is met before the original promise resolves, the returned promise is rejected with a DeadlineError.
If the original promise rejects, the returned promise also rejects with the original promise's rejection reason.

Cancellation:

You can cancel the deadline manually by providing an AbortSignal in the options object and aborting the signal elsewhere in your code.

Notes:

The catch block within the deadline function does nothing on abort to prevent potential errors due to rejected signals.

`delay`

Resolves a Promise after a given amount of milliseconds.

Type:

function delay(ms: number, options?: DelayOptions): Promise<void>;

Example:

import { delay } from '@hemjs/notions';

async function doSomethingAfterDelay() {
  await delay(2000); // Wait for 2 seconds
  console.log('Done!');
}

doSomethingAfterDelay();

Parameters:

ms: The number of milliseconds to wait before resolving the promise.
options: (Optional) An object containing:
- signal: An AbortSignal object to manually abort the delay.

Returns:

A promise that resolves after the specified delay, with no data to fulfill.

Errors:

If the delay is aborted using the AbortSignal, the promise is rejected with the reason provided by the signal.

Cancellation:

You can cancel the delay before it completes by providing an AbortSignal in the options object and aborting the signal elsewhere in your code.

Notes:

The function uses setTimeout internally to create the delay.
The provided AbortSignal is used to listen for abort events and reject the promise accordingly.

Lang

`isBoolean`

Determines whether a given value is of type boolean.

Type:

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

Example:

import { isBoolean } from '@hemjs/notions';

isBoolean(false);
// => true
isBoolean(0);
// => false
isBoolean(null);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is a boolean, otherwise false.

`isFunction`

Determines whether a given value is of type function.

Type:

function isFunction(value?: any): value is Function;

Example:

import { isFunction } from '@hemjs/notions';

isFunction(() => {});
// => true
isFunction(Math.random);
// => true
isFunction(0);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is a function, otherwise false.

`isNil`

Determines whether a given value is nullish (null or undefined).

Type:

function isNil(value?: any): value is null | undefined;

Example:

import { isNil } from '@hemjs/notions';

isNil(null);
// => true
isNil(undefined);
// => true
isNil(0);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is nullish, otherwise false.

`isNull`

Determines whether a given value is exactly null.

Type:

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

Example:

import { isNull } from '@hemjs/notions';

isNull(null);
// => true
isNull(undefined);
// => false
isNull(0);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is null, otherwise false.

`isNumber`

Determines whether a given value is of type number.

Type:

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

Example:

import { isNumber } from '@hemjs/notions';

isNumber(10);
// => true
isNumber(Math.PI);
// => true
isNumber('10');
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is a number, otherwise false.

`isObject`

Determines whether a given value is of type object (excluding null).

Type:

function isObject(value?: any): value is object;

Example:

import { isObject } from '@hemjs/notions';

isObject({});
// => true
isObject([]);
// => true
isObject(null);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is an object (excluding null), otherwise false.

`isPlainObject`

Determines whether a given value is a plain object (i.e., an object without a custom prototype).

Type:

function isPlainObject(value?: any): value is object;

Example:

import { isPlainObject } from '@hemjs/notions';

isPlainObject({});
// => true
isPlainObject([]);
// => false
isPlainObject(Object.create(null));
// => true

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is a plain object, otherwise false.

`isString`

Determines whether a given value is of type string.

Type:

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

Example:

import { isString } from '@hemjs/notions';

isString('hello');
// => true
isString(Symbol('hello'));
// => false
isString(10);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is a string, otherwise false.

`isSymbol`

Determines whether a given value is of type symbol.

Type:

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

Example:

import { isSymbol } from '@hemjs/notions';

isSymbol(Symbol('hello'));
// => true
isString('hello');
// => false
isSymbol(10);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is a symbol, otherwise false.

`isUndefined`

Determines whether a given value is undefined.

Type:

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

Example:

import { isUndefined } from '@hemjs/notions';

isUndefined(undefined);
// => true
isUndefined(null);
// => false
isUndefined(0);
// => false

Parameters:

value: The value to be checked. Can be any data type.

Returns:

true if value is undefined, otherwise false.

Object

`omit`

Creates a new object with specific properties omitted from a source object.

Type:

function omit<TObj extends Record<string, any>>(
  obj: TObj,
  exclusions: (keyof TObj)[],
): TObj;

Example:

import { omit } from '@hemjs/notions';

const person = { name: 'Alice', age: 30, city: 'Nairobi' };
const publicInfo = omit(person, ['age']);
console.log(publicInfo); // Output: { name: 'Alice', city: 'Nairobi' }

Parameters: