js-utilifns

A collection of JavaScript utility functions for common operations on dates, numbers, objects, arrays and strings. This library was built to improve my developer's knowledge of JavaScript while creating a useful set of tools for personal projects and, potentially, for others in the community. js-utilifns aims to provide a consistent and reliable set of functions, reducing the need for repetitive coding.

Features

• Functions for manipulating arrays, dates, numbers, objects, and strings.
• Each function includes error handling and input validation for increased reliability.
• Simple and easy-to-use API with clear JSDoc documentation.
• ES6 module-based structure for easy imports in modern JavaScript projects.
• Comprehensive unit tests using Jest.

Installation

You can install js-utilifns using npm or yarn:

npm install js-utilifns

If using yarn:

yarn add js-utilifns

Documentation (JSDoc)

You can View documentation here

Usage

You can import individual utility functions as needed:

Example: Using getDayOfTheWeek() from dateUtils.js

import { getDayOfTheWeek } from ".js-utilifns";

console.log(getDayOfTheWeek(new Date("2025-03-26"))); // Outputs: "Wednesday"
console.log(getDayOfTheWeek(new Date("2020,10,01"))); // Outputs: "Thursday"

Example: Using getRandomInt() from numberUtils.js

import { getRandomInt } from "js-utilifns";

console.log(getRandomInt(1, 10)); // Outputs a random integer between 1 and 10

Example: Using hasKey() from objectUtils.js

import { hasKey } from "js-utilifns";

const newObject = {name: "John Doe", age: 42};
console.log(hasKey(newObject, "name")); // Outputs: true

Available Utility Functions

Date Utilities (dateUtils.js)

| Function | Description | |-----------------------------|---------------------------------------------------------| | getDayOfTheWeek(date) | Returns the day of the week (e.g., "Monday"). | | diffInDays(date1, date2) | Calculates the number of days between two dates. | | diffInMonths(date1, date2)| Calculates the number of months between two dates. | | diffInYears(date1, date2) | Calculates the number of years between two dates. | | isLeapYear(year) | Checks if a given year is a leap year. |

Number Utilities (numberUtils.js)

| Function | Description | |----------------------------------|-----------------------------------------------------------------------------------------------------------------------| | isEven(number) | Checks if a number is even. Returns true if even, false if odd, and undefined if input is invalid. | | isOdd(number) | Checks if a number is odd. Returns true if odd, false if even, and undefined if input is invalid. | | roundTo(number, decimalPlaces) | Rounds a number to a specified decimal place. Returns NaN if input is invalid. | | getRandomInt(min, max) | Generates a random integer within a specified range (inclusive). Returns NaN if inputs are invalid. | | sum(numbersArray) | Returns the sum of all numbers in an array. Returns NaN if input is not a valid array or contains non-numeric values. |

Object Utilities (objectUtils.js)

| Function | Description | |--------------------------------|---------------------------------------------------------------------------------------------------------------------------------| | isEmpty(obj) | Checks if an object is empty (has no enumerable properties). Returns true if empty, false otherwise. | | merge(target, source) | Merges two objects, with properties from the second object overwriting those in the first. | | deepClone(obj) | Creates a deep clone of an object. Returns a new object with the same properties. | | hasKey(obj, key) | Checks if an object has a specific property as its own (not inherited). Returns true if property exists, false otherwise. | | get(obj, path, defaultValue) | Retrieves the value at a given path within an object. Returns the value at the specified path or the default value. | | set(obj, path, value) | Sets the value at a given path within an object. Returns the updated object. |

String Utilities (stringUtils.js)

| Function | Description | |------------------------------|-------------------------------------------------------------------------------------------------------------------| | capitalize(str) | Capitalizes the first letter of a string. Returns the capitalized string or an empty string if input is invalid. | | camelCase(str) | Converts a string to camelCase. Returns the camelCased string. | | kebabCase(str) | Converts a string to kebab-case. Returns the kebab-cased string. | | snakeCase(str) | Converts a string to snake_case. Returns the snake_cased string. | | truncate(str, length) | Truncates a string to a specified length, adding "..." if truncated. Returns the truncated string. | | reverseString(str) | Reverses a string. Returns the reversed string. | | countOccurrences(str, sub) | Counts the occurrences of a substring within a string. Returns the number of occurrences. | | startsWith(str, prefix) | Checks if a string starts with a given substring. Returns true if it starts with the prefix, false otherwise. | | endsWith(str, suffix) | Checks if a string ends with a given substring. Returns true if it ends with the suffix, false otherwise. | | removeWhitespace(str) | Removes all whitespace from a string. Returns the string without whitespace. |

Array Utilities (arrayUtils.js)

| Function | Description | |------------------------------|-------------------------------------------------------------------------------------------------------------------| | isArrayEmpty(arr) | Checks if an array is empty . | | isArrayEqual(arr1, arr2) | Performs a shallow comparison to check if two arrays are equal in both value and order. | | chunkArray(array, size) | Splits an array into smaller arrays ("chunks") of a specified size. | | removeDuplicates(array) | Removes duplicate primitive values from an array | | removeFalsy(array) | Remove falsy values from an array | | difference(arr1, arr2) | Returns the elements in the first array that are not present in the second array. Case-sensitive comparison. | | intersection(arr1, arr2) | Returns common elements between two arrays. Case-sensitive comparison. | | hasDuplicates(array) | Checks if an array contains duplicate values |

Running Tests

This library is thoroughly tested using Jest. You can run the tests locally by running:

npm test

License

This project is licensed under the MIT License. You are free to use, modify, and distribute it.

Contributing

Want to contribute? Follow these steps:

1. Fork the repository.
2. Create a new branch (feature-xyz).
3. Make your changes and commit them.
4. Push to your forked repo.
5. Open a Pull Request .

Contact

Author: Tiago Costa Rebelo

Have suggestions or found a bug? Open an issue or reach out!

Support the Project

Star this repo if you found it useful!