onix-core/src/fn/date/DateExtensions.ts

Onix library core

import toSafeInteger from 'lodash/toSafeInteger';
import { DateInterval, normalize } from './DateInterval';

declare global {
    interface Date {
       addDays(days: number): Date;
       diff(date: Date): DateInterval;
    }
 }

 Date.prototype.addDays = function(days: number): Date {
    let date = new Date(this.getTime());
    if (!days) return date;
    date.setDate(date.getDate() + days);
    return date;
 };

 Date.prototype.diff = function(date: Date): DateInterval {
    let d1: Date = this; 
    let d2: Date = date; 

    const result: DateInterval = {
        y: 0,
        m: 0,
        d: 0,
        h: 0,
        i: 0,
        s: 0,
        f: 0,
        invert: false,
        days: false
    };
    
    if (date.getTime() > this.getTime()) {
        d1 = date; d2 = this; result.invert = true;
    }

    result.y = d1.getUTCFullYear() - d2.getFullYear();
    result.m = d1.getUTCMonth() - d2.getUTCMonth();
    result.d = d1.getUTCDate() - d2.getUTCDate();
    result.h = d1.getUTCHours() - d2.getUTCHours();
    result.i = d1.getUTCMinutes() - d2.getUTCMinutes();
    result.s = d1.getUTCMinutes() - d2.getUTCSeconds();
    result.f = d1.getUTCMilliseconds() - d2.getUTCMilliseconds();
    result.days = toSafeInteger(Math.abs((d1.getTime() - d2.getTime()) / 86400000));

    if (result.invert) {
        normalize(result, d2);
    } else {
        normalize(result, d1);
    }
    
    return result;
 };

export function DateExtensions() {}