ts-utls

ts-utls is a small TypeScript library where I put all useful stuff I regularly need in my projects.
Feel free to use at your discretion with the apppropriate license mentions.

NB: I've developed the same kind of libraries for both Go and Python.

Usage

npm i ts-utls

This library contains the following functions:

• For arrays:
  • chunk: split an array into chunks of a maximum size;
  • flatten: transform an array of arrays of items to an array of items;
  • groupBy: group an array of items by some item's field;
  • range: return a list of integers;
• For bits and buffers:
  • buffer2BytesString: transform a byte array to its string representation of byte(s);
  • int2Buffer: convert an integer to its byte array equivalent;
  • splitBuffer: split a byte array using a passed byte array;
  • stringBytes2Buffer: transform a string representing one or more bytes to a byte array;
• For JSON:
  • ConvertJSON.toClass: allows casting a JSON string to the targeted class instance;
• For numbers:
  • euclideanDivision: compute the euclidean division of two integers, returning the quotient and the remainder;
• For strings:
  • capitalize: capitalize the first letter of a sentence;
  • fromHex and toHex: transform hexadecimal string representation to byte array, and vice-versa;
  • hashCode: compute the equivalent of Java's hashCode;
  • reverse: reverse the order of characters;
  • shuffle: randomly shuffle the characters;
  • splitCamelCaseWords: put a space between each "word" found in a camel-case string;
  • xor: apply the XOR logical function to two strings in the sense that each charCode is xored;
• For time:
  • currentTimestampMillis: return the current Unix timestamp in milliseconds;
  • sleep: hold the current thread for a while.

eg.

import {
  buffer2BytesString, capitalize, chunk, currentTimestampMillis, flatten, groupBy, euclideanDivision, fromHex,
  int2Buffer, hashCode, range, reverse, shuffle, sleep, splitBuffer, splitCamelCaseWords, stringBytes2Buffer, toHex, xor
} from 'ts-utls'

// For arrays

const arr = [1, 2, 3, 4, 5]
const chunked = chunk(arr)
// [[1, 2], [3, 4], [5]]
console.log(chunked)

const arrs = [[1, 2], [3, 4], [5]]
const flattened = flatten(arrs)
// [1, 2, 3, 4, 5]
console.log(flattened)

const arr = [{ field1: '1', field2: 1 }, { field1: '1', field2: 2 }, { field1: '3', field2: 3 }]
const grouped = groupBy(arr, 'field1')
console.assert(grouped['1'].length === 2)

const firstFive = range(0, 5)
// [0, 1, 2, 3, 4]
console.log(firstFive)
const evenBefore10 = range(0, 10, 2)
// [0, 2, 4, 5, 6, 8]
console.log(evenBefore10)

// For bits and buffers

const buf0 = Buffer.from([0, 1, 128, 2, 3])
const delimiter = Buffer.from([128])
const splitsWithout = splitBuffer(buf0, delimiter, false)
// [[0, 1], [2, 3]]
console.log(splitsWithout)
const splitsWith = splitBuffer(buf0, delimiter, true)
// [[0, 1], [128], [2, 3]]
console.log(splitsWith)

const buf1 = int2Buffer(1)
console.assert(buf1[0] === 1)

const str = '11011010'
const buf2 = stringBytes2Buffer(str)
console.assert(buf1[0] === 218)
const str2 = buffer2BytesString(buf2)
console.assert(str === str2)

// For JSON
const myClass = ConvertJSON.toClass(json, MyClass)
assert(myClass instanceof MyClass)

// For numbers

const n = 15, d = 2
const [q, r] = euclideanDivision(n, d)
console.assert(q === 7 && r === 1)

// For strings

const phrase = capitalize('my sentence is capitalized')
console.assert(phrase === 'My sentence is capitalized')

const h = hashCode('Hello')
console.assert(h === 69609650)

const hexStrings = ['ff']
const buffers = hexStrings.map(fromHex)
const strings = buffers.map(toHex)
console.assert(hexStrings[0] === strings[0])

const toReverse = 'abcd'
const reversed = reverse(toReverse)
console.assert(reversed === 'dcba')

const str = 'abcd'
const shuffled = shuffle(str)
console.assert(str.length === shuffled.length)
console.assert(str !== shuffled)

const sentence = splitCamelCaseWords('myCamelCase')
console.assert(sentence === 'my Camel Case')

const a = 'a'
const b = 'b'
const xored = xor(a, b)
console.assert(xored === '\u0003')

// For time

const ts = currentTimestampMillis()
await sleep(100)
console.assert(currentTimestampMillis() > ts + 100)

Please let me know if you have more optimized implementations of any of my stuff.

Dependencies

To run the tests, you would need to install live-server:

npm i -g live-server

License

This library is distributed under an MIT license. See the LICENSE file.

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© 2020-2022 Cyril Dever. All rights reserved.