@rqi/lotide v1.0.0

Lotide

A mini clone of the Lodash library.

Purpose

BEWARE: This library was published for learning purposes. It is not intended for use in production-grade software.

This project was created and published by me as part of my learnings at Lighthouse Labs.

Usage

Install it:

npm install @ruilinqi/lotide

Require it:

const _ = require('@ruilinqi/lotide');

Call it:

const results = _.tail([1, 2, 3]) // => [2, 3]

Documentation

The following functions are currently implemented:

• assertArraysEqual(actual, expected): Takes in two arrays, and asserts whether two arrays are equal.

assertArraysEqual([1, 2, 3], [1, 2, 3]);
// => ✅✅✅ Assertion Passed: [1, 2, 3] === [1, 2, 3]
assertArraysEqual([1, 2, 3], [3, 2, 1]);
// => ❌❌❌ Assertion Failed: [1, 2, 3] !== [3, 2, 1]

• assertEqual(actual, expected): Takes in two primitive values, and asserts whether they are equal.

assertEqual("lighthouse", "lighthouse");
// => ✅✅✅ Assertion Passed: lighthouse === lighthouse
assertEqual("lighthouse", "Lighthouse");
// => ❌❌❌ Assertion Failed: lighthouse !== Lighthouse

• assertObjectsEqual(actual, expected): Takes in two objects, and asserts whether they are equal.

assertObjectsEqual({ a: '1', b: '2' }, { b: '2', a: '1' });
// => ✅✅✅ Assertion Passed: { a: '1', b: '2' } === { b: '2', a: '1' }
assertObjectsEqual({ a: '1', b: '2' }, { a: '1', b: '2', c: '3' });
// => 🛑🛑🛑 Assertion Failed: { a: '1', b: '2' } !== { a: '1', b: '2', c: '3' }

• countLetters(str): Returns an object containing counts of every letter in an input string.

countLetters("lighthouse in the house");
// => { l: 1, i: 2, g: 1, h: 4, t: 2, o: 2, u: 2, s: 2, e: 3, n: 1 }

• countOnly(allItems, itemsToCount): Returns a number to count the specific objects in the array.

const allItems = [
  "Karl",
  "Salima",
  "Agouhanna",
  "Fang",
  "Kavith",
  "Jason",
  "Salima",
  "Fang",
  "Joe"
];
const itemsToCount = {'Salima':true, 'Joe': true};
countOnly(allItems, itemsToCount);
// => { Salima: 2, Joe: 1 }

• eqArrays(actual, expected): Takes in two arrays, and asserts whether they are equal. It returns true or false.

eqArrays([1, 2, 3], [1, 2, 3]); // => true
eqArrays([1, 2, 3], [2, 3, 4]); // => false

• eqObjects(actual, expected): Takes in two objects, and asserts whether they are equal. It returns true or false.
• findkey(object, callback): Takes in an object and a callback function. It returns the first key for which the callback returns a truthy value.
• findkeyByValue(object, value): Takes in an object and a value. It scans the object and return the first key which contains the given value. and asserts whether they are equal.
• head(array): Returns the first element of the array.
• letterPositions(sentence): Returns all the indices (zero-based positions) in the string where each character is found.
• map(array, callback): Takes in an array to map and a callback function, and returns a new array based on the callback function.
• middle(array): Returns the element in the middle of the array.
• tail(array): Returns the tail (all elements except for the first item (head)) of the provided array.
• takeUntil(array): Returns the elements of an array that taken from the beginning until the callback function returns a truthy value.

const data2 = ["I've", "been", "to", "Hollywood", ",", "I've", "been", "to", "Redwood"];
takeUntil(data2, x => x === ',');
// => [ "I've", 'been', 'to', 'Hollywood' ]

• without(soureArray, itemsToRemoveArray): Takes in a source array and a itemsToRemove array. It returns a new array with only those elements from source that are not present in the itemsToRemove array.

without([1, 2, 3], [1]);
// => [2, 3]

const words = ["hello", "world", "lighthouse"];
without(words, ["lighthouse"]);
// => [ 'hello', 'world' ]