Lotide

A mini-clone of the Lodash library.

Author :

Hatem : Github: @AH82 | npm: @hatem.deux

Author's Notes :

• This project is a part of a learning experience as a student at Lighthouse Labs's Full-Stack Web-Developper Bootcamp course.
• This is my very first project.
• Main focus:
  • Data manipulation (arrays and objects)
  • Callbacks
  • Recursion
  • export / import (require)
  • TDD / BDD with Mocha & Chai
• Most commented-out code is kept intentionally for learning, improvement & future awareness purposes.
• These are especially at the bottom of Test files.
• This project was revisited post-bootcamp and implemented additional excercises, did major clean up and fixed a couple of bugs.

Table of contents

• Setup
  • Install via npm
  • Clone it from GitHub
• Dependencies
  • DevDependencies
• Documentation
  • Main Functions
  • Comparison functions
  • Custom Assertion functions
  • Testing
    • Running Test
• Change History
  • v1.0.1
    • Improvements
    • Bug fixes
  • v1.0.0

Setup

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CAUTION:
This library is published as a part of a learning process. It is not meant for use in serious projects.

Install via npm:

In your Terminal:

> npm install @hatem.deux/lotide

At the top of your JavaScript code:

const _ = require('@hatem.deux/lotide');

Call it (example):

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

Clone it from GitHub

in your terminal:

> git clone git@github.com:AH82/lotide.git

Dependencies

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Install Dependencies in the terminal:

> npm install

DevDependencies

• Mocha Test Suite
• Chai assertion library

> npm install --save-dev mocha chai

Documentation

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Main Functions

• All functions are in files of "./<function name>.js"
• index.js exports all these functions.

Function name	parameter	Description
head	array	returns the value of the first (head) element in an array.
tail	array	returns an array of remaining element in an array.
middle	array	returns an array of middle element(s) in an array (1 for odd, 2 for even).
without	SourceArray, itemsToRemoveArray	returns a filtered-out new array.
flatten	array	returns a flattened array from a multi-level nested one in the same element-order (i.e. removes nesting)
countOnly	array, itemsToCountObject	returns an object containing counts of everything the input object listed.
countLetters	string	returns an object a count of each of the letters in that sentence. ignores whitespaces.
letterPositions	string	returns an object with all the indices (zero-based positions) in the string where each character is found. (property-value is an array)
findKeyByValue	object, value	scans the object and return the first key which contains the given value. If no key with that given value is found, then it should return undefined.
map	array, callback	returns an array modified by the callback.
takeUntil	array, callback	returns a slice of the array with elements taken from the beginning until callback returns a truthy value.
findKey	object, callback	returns the first key for which the callback returns a truthy value. If not found, returns undefined.

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Comparison functions

These functions are not included in index.js.

Function name	parameter	Description
eqArrays	array1, array2	deep-compares arrays. returns true if identical. false if not.
eqObjects	object1, object2	deep-compares objects. returns true if identical. false if not.

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Custom Assertion functions

These functions are not included in index.js.

These functions were used during development and are no longer required by other functions. They are kept for archiving and the learning experience.

These are side-effects function do not return, they produce console.logs indicating success or failure of Assertion. They typically use the Comparison functions as inputs to assert.

Function name	parameter	Description
assertEqual	bool	for regular values
assertArraysEqual	bool	for arrays
assertEqualObjects	bool	for objects

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Testing

Using Mocha/Chai

• All test files are under "./test/"
  • except "Custom Assertion functions" intentionally placed under "./test/customAssertTests" to be ignored by test run.
• All Test files are named by the convention "./test/<function name>Test.js"

Running Test

• At project root folder in the terminal

> mocha

or

> npm test

Change History

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v1.0.2

• upgrades to version 1.0.2 to fix an npm unpublishing/publishing accidental issue.
• fixes a minor issue in the interlinks of REAMDME.md

v1.0.1

---

Improvements

• eqArrays & eqObjects now support deep comparison (through recursion)
• README.md redesigned.
• lints, cleans and removes redundant, dead or commented-out code across entire project, except when intentional.
• Testing
  • The entire code is now covered by tests.
  • Any in-file custom tests (console.log or custom assertions) moved to the "./test/*" folders.
  • Any remaining custom tests are converted to Mocha/Chai code.
    • except: custom Assertions due to side-effect nature (but rapped in Mocha's describe/it )

Bug fixes

• takeUntil.js
  • Issue: returns undefined if the callback argument does not match an element. (i.e. does not find a truthy element).
  • Fix: returns the entire array if no match.
• without.js
  • Issue: Does not return a new array. (i.e. modifies the original).
  • Fix: returns a new array.
• index.js
  • fixes typo: findKeysByValue => findKeyByValue
• package.json
  • Issue: "main" refered to the incorrect file => { ..., "main": "assertArraysEqual.js", ... }
  • Fix: "main" now referes to the correct file => { ..., "main": "index.js", ... }
• functions findKeysByValue, letterPositions, map, takeUntil, without, findKey are now implemented. (on npm package only)

v1.0.0

---

• Initial release.

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