A collection of utility functions I find myself needing across multiple projects

Functions can be required individually like so: const fn = require('@ack_inc/utils/lib/<fn-name-in-kebab-case>')

Generates a string of length nChars that satisfies constraints

Use case: password or temporary token generation

constraints may have the following keys:

If constraints has none of the above keys, it is assumed that all characters are allowed

Look in lib/generate-random-string.js for the full list of symbols used

const { generateRandomString: rsg } = require('@ack_inc/utils');
console.log(rsg(<anything but a whole number>)); //=> throws TypeError
console.log(rsg(0)); //=> ""
console.log(rsg(5)); //=> "3`8aE"
console.log(rsg(5, { lowercase: true })); //=> "fewjk"
console.log(rsg(5, { lowercase: true, uppercase: true, digits: true, symbols: true })); //=> "%q31G"

Group an array of records into an array of sub-arrays of records. Records go into the same sub-array ("group") if any of the keys generated by getKeys are === equal

Use case: you have an array of records (of people, say); the records are from multiple sources, and you want to merge records (for belonging to the same person) if any of several different "identifiers" (email, phone number, social media handle, etc.) match

It may not be the case that there is a common key for all the records in a group. Further, there may be two records in a group that have no keys in common. For example, the following three records will be in the same group, through A and C do not have a common key, because they each have a key in common with another record in the group:

• Record A with keys ['a', 'b']
• Record B with keys ['b', 'c']
• Record C with keys ['c', 'd']

See the tests in lib/group-by-multi-keys.test.js for usage examples

Format a mobile number (must include country code) in different ways

In formatString, only the following characters will be transformed:

Any other characters will appear as-is in the returned string

const { formatMobileNumber: format } = require('@ack_inc/utils');
console.log(format(<anything but a mobile number with country code>)); //=> throws Error

const mobile = "+1 123 456 7890";
expect(format(mobile)).toEqual("+11234567890");
expect(format(mobile, "+CASR")).toEqual("+11234567890");
expect(format(mobile, "+C A S R")).toEqual("+1 123 456 7890");
expect(format(mobile, "+C (A) S-R")).toEqual("+1 (123) 456-7890");

Format a mobile number (must include country code) in different ways

const { buildArr } = require('@ack_inc/utils');

expect(buildArr(0)).toEqual([]);
expect(buildArr(2)).toEqual([0, 1]);
expect(buildArr(2, idx => idx + 1)).toEqual([1, 2]);

Group records according to groupFn

A record is any object with an id key

• See group-by.test.js

• Automated documentation generation

• Improve generateRandomString

  • Constraint: whitelisted chars
  • Constraint: blacklisted chars
  • Constraint: symbols that can be part of a url-component (See SO answer)