debian-mirror-gitlab/app/assets/javascripts/lib/utils/number_utils.js
2021-04-17 20:07:23 +05:30

173 lines
4.6 KiB
JavaScript

import { sprintf, __ } from '~/locale';
import { BYTES_IN_KIB } from './constants';
/**
* Function that allows a number with an X amount of decimals
* to be formatted in the following fashion:
* * For 1 digit to the left of the decimal point and X digits to the right of it
* * * Show 3 digits to the right
* * For 2 digits to the left of the decimal point and X digits to the right of it
* * * Show 2 digits to the right
*/
export function formatRelevantDigits(number) {
let digitsLeft = '';
let relevantDigits = 0;
let formattedNumber = '';
if (!Number.isNaN(Number(number))) {
[digitsLeft] = number.toString().split('.');
switch (digitsLeft.length) {
case 1:
relevantDigits = 3;
break;
case 2:
relevantDigits = 2;
break;
case 3:
relevantDigits = 1;
break;
default:
relevantDigits = 4;
break;
}
formattedNumber = Number(number).toFixed(relevantDigits);
}
return formattedNumber;
}
/**
* Utility function that calculates KiB of the given bytes.
*
* @param {Number} number bytes
* @return {Number} KiB
*/
export function bytesToKiB(number) {
return number / BYTES_IN_KIB;
}
/**
* Utility function that calculates MiB of the given bytes.
*
* @param {Number} number bytes
* @return {Number} MiB
*/
export function bytesToMiB(number) {
return number / (BYTES_IN_KIB * BYTES_IN_KIB);
}
/**
* Utility function that calculates GiB of the given bytes.
* @param {Number} number
* @returns {Number}
*/
export function bytesToGiB(number) {
return number / (BYTES_IN_KIB * BYTES_IN_KIB * BYTES_IN_KIB);
}
/**
* Port of rails number_to_human_size
* Formats the bytes in number into a more understandable
* representation (e.g., giving it 1500 yields 1.5 KB).
*
* @param {Number} size
* @returns {String}
*/
export function numberToHumanSize(size) {
if (size < BYTES_IN_KIB) {
return sprintf(__('%{size} bytes'), { size });
} else if (size < BYTES_IN_KIB * BYTES_IN_KIB) {
return sprintf(__('%{size} KiB'), { size: bytesToKiB(size).toFixed(2) });
} else if (size < BYTES_IN_KIB * BYTES_IN_KIB * BYTES_IN_KIB) {
return sprintf(__('%{size} MiB'), { size: bytesToMiB(size).toFixed(2) });
}
return sprintf(__('%{size} GiB'), { size: bytesToGiB(size).toFixed(2) });
}
/**
* A simple method that returns the value of a + b
* It seems unessesary, but when combined with a reducer it
* adds up all the values in an array.
*
* e.g. `[1, 2, 3, 4, 5].reduce(sum) // => 15`
*
* @param {Float} a
* @param {Float} b
* @example
* // return 15
* [1, 2, 3, 4, 5].reduce(sum);
*
* // returns 6
* Object.values([{a: 1, b: 2, c: 3].reduce(sum);
* @returns {Float} The summed value
*/
export const sum = (a = 0, b = 0) => a + b;
/**
* Checks if the provided number is odd
* @param {Int} number
*/
export const isOdd = (number = 0) => number % 2;
/**
* Computes the median for a given array.
* @param {Array} arr An array of numbers
* @returns {Number} The median of the given array
*/
export const median = (arr) => {
const middle = Math.floor(arr.length / 2);
const sorted = arr.sort((a, b) => a - b);
return arr.length % 2 !== 0 ? sorted[middle] : (sorted[middle - 1] + sorted[middle]) / 2;
};
/**
* Computes the change from one value to the other as a percentage.
* @param {Number} firstY
* @param {Number} lastY
* @returns {Number}
*/
export const changeInPercent = (firstY, lastY) => {
if (firstY === lastY) {
return 0;
}
return Math.round(((lastY - firstY) / Math.abs(firstY)) * 100);
};
/**
* Computes and formats the change from one value to the other as a percentage.
* Prepends the computed percentage with either "+" or "-" to indicate an in- or decrease and
* returns a given string if the result is not finite (for example, if the first value is "0").
* @param firstY
* @param lastY
* @param nonFiniteResult
* @returns {String}
*/
export const formattedChangeInPercent = (firstY, lastY, { nonFiniteResult = '-' } = {}) => {
const change = changeInPercent(firstY, lastY);
if (!Number.isFinite(change)) {
return nonFiniteResult;
}
return `${change >= 0 ? '+' : ''}${change}%`;
};
/**
* Checks whether a value is numerical in nature by converting it using parseInt
*
* Example outcomes:
* - isNumeric(100) = true
* - isNumeric('100') = true
* - isNumeric(1.0) = true
* - isNumeric('1.0') = true
* - isNumeric('abc100') = false
* - isNumeric('abc') = false
* - isNumeric(true) = false
* - isNumeric(undefined) = false
* - isNumeric(null) = false
*
* @param value
* @returns {boolean}
*/
export const isNumeric = (value) => {
return !Number.isNaN(parseInt(value, 10));
};