petergi

#!/usr/bin/env bash
# =============================================================================
# cleanup-branches.sh — Bulk delete GitHub branches with whitelist protection
# =============================================================================
#
# Usage:
#   ./cleanup-branches.sh --repo owner/repo --whitelist whitelist.txt [OPTIONS]
#
# Options:
#   --repo OWNER/REPO        Target repository (required)

petergi

Checks if the given date is a weekday.

- Use `Date.prototype.getDay()` to check weekday by using a modulo operator (`%`).
- Omit the argument, `d`, to use the current date as default.


const isWeekday = (d = new Date()) => d.getDay() % 6 !== 0;


isWeekday(); // true (if current date is 2019-07-19)

petergi

// Checks if the given date is a weekend.
// - Use `Date.prototype.getDay()` to check weekend by using a modulo operator (`%`).
// - Omit the argument, `d`, to use the current date as default.

const isWeekend = (d = new Date()) => d.getDay() % 6 === 0;

isWeekend(); // 2018-10-19 (if current date is 2018-10-18)

petergi

// Filters an array of objects based on a condition while also filtering out unspecified keys.
// 
// - Use `Array.prototype.filter()` to filter the array based on the predicate `fn` so that it returns the objects for which the condition returned a truthy value.
// - On the filtered array, use `Array.prototype.map()` to return the new object.
// - Use `Array.prototype.reduce()` to filter out the keys which were not supplied as the `keys` argument.


const reducedFilter = (data, keys, fn) =>
  data.filter(fn).map(el =>
    keys.reduce((acc, key) => {

petergi

// 
// Creates an array with the unique values filtered out.
// 
// - Use the `Set` constructor and the spread operator (`...`) to create an array of the unique values in `arr`.
// - Use `Array.prototype.filter()` to create an array containing only the non-unique values.


const filterUnique = arr =>[...new Set(arr)].filter(i => arr.indexOf(i) !== arr.lastIndexOf(i));
filterUnique([1, 2, 2, 3, 4, 4, 5]); // [2, 4]

petergi

// Finds all the keys in the provided object that match the given value.
// 
// - Use `Object.keys()` to get all the properties of the object.
// - Use `Array.prototype.filter()` to test each key-value pair and return all keys that are equal to the given value.

const findKeys = (obj, val) => Object.keys(obj).filter((key) => obj[key] === val);
const ages = {
  Leo: 20,
  Zoey: 21,
  Jane: 20,

petergi

function intToBin(number) {
    if (number === 0) {
        return '0';
    }
    let res = '';
    while (number > 0) {
        res = String(number % 2) + res;
        number = parseInt(number / 2, 10);
    }

petergi

// Checks if a string contains only alphanumeric characters.
// 
// - Use `RegExp.prototype.test()` to check if the input string matches against the alphanumeric regexp pattern.


const isAlphaNumeric = str => /^[a-z0-9]+$/gi.test(str);

isAlphaNumeric('hello123'); // true
isAlphaNumeric('123'); // true
isAlphaNumeric('hello 123'); // false (space character is not alphanumeric)

petergi

Checks if a string is an anagram of another string (case-insensitive, ignores spaces, punctuation and special characters).

- Use `String.prototype.toLowerCase()` and `String.prototype.replace()` with an appropriate regular expression to remove unnecessary characters.
- Use `String.prototype.split()`, `Array.prototype.sort()` and `Array.prototype.join()` on both strings to normalize them, then check if their normalized forms are equal.


const isAnagram = (str1, str2) => {
  const normalize = str =>
    str
      .toLowerCase()

petergi

Checks if a valid date object can be created from the given values.

- Use the spread operator (`...`) to pass the array of arguments to the `Date` constructor.
- Use `Date.prototype.valueOf()` and `Number.isNaN()` to check if a valid `Date` object can be created from the given values.


const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());

isDateValid('December 17, 1995 03:24:00'); // true
isDateValid('1995-12-17T03:24:00'); // true