Get unlimited public & private packages + team-based management with npm Teams.Learn more »

@rahmatsaeedi/lotide

1.0.1 • Public • Published

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 @rahmatsaeedi/lotide

Require it:

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

Call it:

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

Documentation

The following functions are currently implemented:

  • assertEqual(actual, expected, suppressLogging = false): A custom assert function with emoji icons. Returns a Boolean value.

    assertEqual("Bootcamp", "Bootcamp")
    // => ✅  Assertion Passed: Bootcamp === Bootcamp
    // => true
    assertEqual(1, 1)
    // => ✅  Assertion Passed: 1 === 1
    // => true
  • countLetters(string): Returns an object containing count of every character in an input string. The

  • countOnly(array, object): Takes in a collection of items and return an object containing counts of everything that the input object listed. Lotide countOnly

    // Given
    const firstNames = [
      "Karl",
      "Salima",
      "Agouhanna",
      "Fang",
      "Kavith",
      "Jason",
      "Salima",
      "Fang",
      "Joe"
    ];
     
    countOnly(firstNames, { "Jason": true, "Karima": true, "Fang": true });
    // => { Jason: 1, Fang: 2 }
  • eqArrays(array1, array2): Takes in two arrays and returns true or false, based on a perfect match. It also works with nested arrays.

  • eqObjects(object1, object2): Take in two objects, checks whether that the two are identical, and returns a boolean. Supports nested objects with premitive values, and nested arrays.

    eqObjects({ x: 1, y: 2, z: 'w' }, { x: 1, y: 2, z: 'w' }); // => true
    eqObjects({ y: 2, x: 1, z: 'w' }, { x: 1, y: 2, z: 'w' }); // => true
    eqObjects({ x: 1, y:{y: [[2, [2]]], z: {m:'w'}}}, { x: 1, y:{y: [[2, [2]]], z: {m:'w'}} }); // => true
    eqObjects({ x: 1, y: 2, z: 'w' }, { x: 1, y: 2, z: 'w', zz:'zz' }); // => false
  • findKey(object, predicate): This method returns the key of the first element predicate returns truthy. Predicate takes (object[key], key, object).

    findKey({
      "Blue Hill": { stars: 1 },
      "Akaleri":   { stars: 3 },
      "noma":      { stars: 2 },
      "elBulli":   { stars: 3 },
      "Ora":       { stars: 2 },
      "Akelarre":  { stars: 3 }
    }, x => x.stars === 2); // => "noma"
  • findKeyByValue(object, value): Searches for a key in an object where its value matches a given value.

    const bestTVShowsByGenre = {
      sciFi: "The Expanse",
      comedy: "Brooklyn Nine-Nine",
      drama:  "The Wire",
      drama2:  "The Wire"
    };
     
    findKeyByValue(bestTVShowsByGenre, "The Wire");
    // Returns:  'drama'
     
    findKeyByValue(bestTVShowsByGenre, "That '70s Show");
    // Returns:  undefined
  • findKeysByValue(object, value): Searches for keys in an object where its value matches a given value. Returns an array.

    const bestTVShowsByGenre = {
      sciFi: "The Expanse",
      comedy: "Brooklyn Nine-Nine",
      drama:  "The Wire",
      drama2:  "The Wire"
    };
     
    findKeyByValue(bestTVShowsByGenre, "The Wire");
    // Returns:  [ 'drama', 'drama2' ]
     
    findKeyByValue(bestTVShowsByGenre, "That '70s Show");
    // Returns:  []
  • flatten(array): Given an array with other arrays inside, this function can flatten it into a single-level array.

    flatten([1, 2, [3, 4], 5, [6]]) // => [1, 2, 3, 4, 5, 6]
     
    flatten([1, 2, [3, [[[[4]] , 5]]], 6, [7, 8, 9, 10]])
    // => [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
     
    flatten(["1", ["2", ["3"]]]) // => [ '1', '2', '3' ]
  • head(array): Returns the head of an array. Returns 'undefined' for empty array.

    head([1, 2, 3]);
    // => 1
     
    head([]);
    // => undefined
  • letterPositions(string): Returns an object, containing all the indices in the string where each character is found. Indicies are zero-based.

    letterPositions("Hello hehehe");
    /* Returns
    {
      H: [ 0 ],
      h: [ 6, 8, 10 ],
      e: [ 1, 7, 9, 11 ],
      l: [ 2, 3 ],
      o: [ 4 ],
      ' ': [ 5 ]
    }
    */
  • map(array, callBack): Returns a new array based on the results of callback function.
    Requires:

    • An array to map
    • A callback function
    const words = ["ground", "control", "to", "major", "tom"];
    let firstLetters = map(words, word => word[0]);
    // Returns: ['g','c','t','m','t']
  • middle(array): Takes in an array and return the middle-most element(s) of the given array.

    • For arrays with one or two elements, returns an empty array.
    • For arrays with odd number of elements, an array containing a single middle element is returned.
    • For arrays with an even number of elements, an array containing the two elements in the middle is returned.
    middle([1]) // => []
    middle([1, 2]) // => []
     
    middle([1, 2, 3]) // => [2]
    middle([1, 2, 3, 4, 5]) // => [3]
     
     
    middle([1, 2, 3, 4]) // => [2, 3]
    middle([1, 2, 3, 4, 5, 6]) // => [3, 4]
  • min(array): Returns the minimum of an array.

      let testArray = [5, 7, -8, 2, 4, 0, 8, -1, 54, 13];
      min(testArray);
      // => -8
  • tail(array): Returns the tail of an array. ie, everything after the first element.

    tail([1, 2, 3]);
    // => [2, 3]
  • takeUntil(array, predicate): Creates a slice of array with elements taken from the beginning. Elements are taken until predicate returns falsey. The predicate is invoked with three arguments: (value, index, array).

    const data1 = [1, 2, 5, 7, 2, -1, 2, 4, 5];
    const data2 = ["I've", "been", "to", "Hollywood", ",", "I've", "been", "to", "Redwood"];
     
    const results1 = takeUntil(data1, x => x < 0);
    const results2 = takeUntil(data2, x => x === ',');
    // results1 = [1, 2, 5, 7, 2]
    // results2 = ["I've", "been", "to", "Hollywood"]
  • without(array, itemsToRemoveArray): Will return a subset of a given array, removing unwanted elements.

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

Devlopment Testing

Testing requires installing Mocha & Chai. If everything is alright, then npm test should return the following:

  #assertEqual 
    √ returns 'true' for 1===1
    √ returns 'true' for 'bootcamp' === 'bootcamp'
    √ returns 'false' for '7' === 7
 
  #countLetters
    √ return['g'] is 2 for input 'google...'
    √ return['.'] is 3 for input 'google...'
 
  #countOnly
    √ return correct value
    √ is case sensitive
    √ returns 'undefined' for non-existant keys
 
  #eqArrays
    √ returns 'true' for same arrays
    √ returns 'false' for different arrays
    √ returns 'true' for same nested-arrays
    √ returns 'true' for same mixed number-string nested-arrays
 
  #eqObjects
    √ returns 'true' for the same flat-objects with perimitive-values
    √ returns 'false' for unlike simple flat-objects
    √ returns 'true' for the same nested-obeject with nested-array values
    √ returns 'true' for the same nested-obeject with nested-array values
 
  #findKeyByValue
    √ returns the correct key for string-valued values
    √ returns the correct key for integer-valued values
    √ returns 'undefined' if value is not in the object
 
  #findKeysByValue
    √ returns the correct keys for string-valued values
    √ returns the correct keys for integer-valued values
    √ returns '[]' if values is not in the object
 
  #findKey
    √ returns the correct key
    √ returns 'undefined' if none-matches
 
  #flatten
    √ returns the correct array for integer-valued values
    √ returns the correct keys for string-valued values
 
  #head
    √ returns 1 for [1, 2, 3]
    √ returns 'Hello' for ['Hello''Lighthouse''Labs']
    √ returns 'undefined' for []
 
  #letterPositions
    √ returns the correct position-arrays as an object
    √ is case sensitive
    √ returns 'undefined' for characters that don't exist in the string
    √ works with special character: white-space
    √ works with special characters: ~!@#$%^&*()_+|\=-`{}[]":;'<>?/.,
  #map
    √ returns correct output
 
  #middle
    √ returns empty-array if input-array has 1 element
    √ returns empty-array if input-array has 2 elements
    √ returns correct array for arrays with odd number of elements
    √ returns correct array for arrays with even number of elements
 
  #min
    √ returns correct output for all positive valued array
    √ returns correct output for all negative valued array
    √ returns correct output for mixed valued array
 
  #tail
    √ returns the correct output for nonempty input-arrays
    √ returns an empty array for empty input-array
    √ returns an empty array for an array with single element in it
 
  #takeUntil
    √ returns the correct output for integer-valued input-arrays
    √ returns the correct output for string-valued input-arrays
    √ returns an empty array for an empty input-array and 'undefined' callback function
 
  #without
    √ returns the correct output for flat premitive-valued input-arrays
    √ returns the correct output for nested-premitive-valued input-arrays
    √ returns an empty array for an empty input-array
 
 
  51 passing (49ms)

Install

npm i @rahmatsaeedi/lotide

DownloadsWeekly Downloads

0

Version

1.0.1

License

ISC

Unpacked Size

48.3 kB

Total Files

39

Last publish

Collaborators

  • avatar