Add a date class

src/bot.js

@@ -48,6 +48,7 @@ const semlog = require('semlog');
 const log = semlog.log;
 
 const Title = require('./title');
+const Xdate = require('./date');
 const Page = require('./page');
 const Wikitext = require('./wikitext');
 const User = require('./user');
@@ -198,6 +199,11 @@ class mwn {
 		 */
 		this.title = Title;
 
+		/**
+		 * Date class
+		 */
+		this.date = Xdate(this);
+
 		/**
 		 * Page class associated with bot instance
 		 */

src/date.js

@@ -0,0 +1,280 @@
+module.exports = function(bot) {
+
+	/**
+	 * Wrapper around the native JS Date() for ease of
+	 * handling dates, as well as a constructor that
+	 * can parse MediaWiki dating formats.
+	 */
+	class xdate extends Date {
+
+		/**
+		 * Create a date object. MediaWiki timestamp format is also acceptable,
+		 * in addition to everything that JS Date() accepts.
+		 */
+		constructor(...args) {
+
+			if (args.length === 1 && typeof args[0] === 'string') {
+				// parse MediaWiki format: YYYYMMDDHHmmss
+				if (/^\d{14}$/.test(args[0])) {
+					let match = /(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})/.exec(args[0]);
+					match[2] = parseInt(match[2]) - 1; // fix month
+					super(...match.slice(1));
+				} else {
+					// Attempt to remove a comma and paren-wrapped timezone, to get MediaWiki
+					// signature timestamps to parse. Firefox (at least in 75) seems to be
+					// okay with the comma, though
+					args[0] = args[0].replace(/(\d\d:\d\d),/, '$1').replace(/\(UTC\)/, 'UTC');
+					super(...args);
+				}
+			} else {
+				super(...args);
+			}
+
+			// Still no?
+			if (isNaN(this.getTime()) && !bot.options.suppressInvalidDateWarning) {
+				console.warn('Invalid initialisation of xdate object: ', args);
+			}
+		}
+
+		/** @return {boolean} */
+		isValid() {
+			return !isNaN(this.getTime());
+		}
+
+		/**
+		 * @param {(Date|xdate)} date
+		 * @return {boolean}
+		 */
+		isBefore(date) {
+			return this.getTime() < date.getTime();
+		}
+
+		/**
+		 * @param {(Date|xdate)} date
+		 * @return {boolean}
+		 */
+		isAfter(date) {
+			return this.getTime() > date.getTime();
+		}
+
+		/** @return {string} */
+		getUTCMonthName() {
+			return xdate.localeData.months[this.getUTCMonth()];
+		}
+
+		/** @return {string} */
+		getUTCMonthNameAbbrev() {
+			return xdate.localeData.monthsShort[this.getUTCMonth()];
+		}
+
+		/** @return {string} */
+		getMonthName() {
+			return xdate.localeData.months[this.getMonth()];
+		}
+
+		/** @return {string} */
+		getMonthNameAbbrev() {
+			return xdate.localeData.monthsShort[this.getMonth()];
+		}
+
+		/** @return {string} */
+		getUTCDayName() {
+			return xdate.localeData.days[this.getUTCDay()];
+		}
+
+		/** @return {string} */
+		getUTCDayNameAbbrev() {
+			return xdate.localeData.daysShort[this.getUTCDay()];
+		}
+
+		/** @return {string} */
+		getDayName() {
+			return xdate.localeData.days[this.getDay()];
+		}
+
+		/** @return {string} */
+		getDayNameAbbrev() {
+			return xdate.localeData.daysShort[this.getDay()];
+		}
+
+		/**
+		 * Add a given number of minutes, hours, days, months or years to the date.
+		 * This is done in-place. The modified date object is also returned, allowing chaining.
+		 * @param {number} number - should be an integer
+		 * @param {string} unit
+		 * @throws {Error} if invalid or unsupported unit is given
+		 * @returns {xdate}
+		 */
+		add(number, unit) {
+			// mapping time units with getter/setter function names
+			var unitMap = {
+				seconds: 'Seconds',
+				minutes: 'Minutes',
+				hours: 'Hours',
+				days: 'Date',
+				months: 'Month',
+				years: 'FullYear'
+			};
+			var unitNorm = unitMap[unit] || unitMap[unit + 's']; // so that both singular and  plural forms work
+			if (unitNorm) {
+				this['set' + unitNorm](this['get' + unitNorm]() + number);
+				return this;
+			}
+			throw new Error('Invalid unit "' + unit + '": Only ' + Object.keys(unitMap).join(', ') + ' are allowed.');
+		}
+
+		/**
+		 * Subtracts a given number of minutes, hours, days, months or years to the date.
+		 * This is done in-place. The modified date object is also returned, allowing chaining.
+		 * @param {number} number - should be an integer
+		 * @param {string} unit
+		 * @throws {Error} if invalid or unsupported unit is given
+		 * @returns {xdate}
+		 */
+		subtract(number, unit) {
+			return this.add(-number, unit);
+		}
+
+		/**
+		 * Formats the date into a string per the given format string.
+		 * Replacement syntax is a subset of that in moment.js.
+		 * @param {string} formatstr
+		 * @param {(string|number)} [zone=utc] - 'system' (for system-default time zone),
+		 * 'utc' (for UTC), or specify a time zone as number of minutes past UTC.
+		 * @returns {string}
+		 */
+		format(formatstr, zone) {
+			if (!this.isValid()) {
+				return ''; // avoid bogus NaNs in output
+			}
+			var udate = this;
+			// create a new date object that will contain the date to display as system time
+			if (!zone || zone === 'utc') {
+				udate = new xdate(this.getTime()).add(this.getTimezoneOffset(), 'minutes');
+			} else if (typeof zone === 'number') {
+				// convert to utc, then add the utc offset given
+				udate = new xdate(this.getTime()).add(this.getTimezoneOffset() + zone, 'minutes');
+			}
+
+			var pad = function(num) {
+				return num < 10 ? '0' + num : num;
+			};
+			var h24 = udate.getHours(), m = udate.getMinutes(), s = udate.getSeconds();
+			var D = udate.getDate(), M = udate.getMonth() + 1, Y = udate.getFullYear();
+			var h12 = h24 % 12 || 12, amOrPm = h24 >= 12 ? 'PM' : 'AM';
+			var replacementMap = {
+				'HH': pad(h24), 'H': h24, 'hh': pad(h12), 'h': h12, 'A': amOrPm,
+				'mm': pad(m), 'm': m,
+				'ss': pad(s), 's': s,
+				'dddd': udate.getDayName(), 'ddd': udate.getDayNameAbbrev(), 'd': udate.getDay(),
+				'DD': pad(D), 'D': D,
+				'MMMM': udate.getMonthName(), 'MMM': udate.getMonthNameAbbrev(), 'MM': pad(M), 'M': M,
+				'YYYY': Y, 'YY': pad(Y % 100), 'Y': Y
+			};
+
+			// as long as only unbind() and rebind() methods of bot.wikitext are used,
+			// there shouldn't be problems from not having called getSiteInfo() on the bot object
+			var unbinder = new bot.wikitext(formatstr); // escape stuff between [...]
+			unbinder.unbind('\\[', '\\]');
+			unbinder.text = unbinder.text.replace(
+				/* Regex notes:
+				 * d(d{2,3})? matches exactly 1, 3 or 4 occurrences of 'd' ('dd' is treated as a double match of 'd')
+				 * Y{1,2}(Y{2})? matches exactly 1, 2 or 4 occurrences of 'Y'
+				 */
+				/H{1,2}|h{1,2}|m{1,2}|s{1,2}|d(d{2,3})?|D{1,2}|M{1,4}|Y{1,2}(Y{2})?|A/g,
+				function(match) {
+					return replacementMap[match];
+				}
+			);
+			return unbinder.rebind().replace(/\[(.*?)\]/g, '$1');
+		}
+
+		/**
+		 * Gives a readable relative time string such as "Yesterday at 6:43 PM" or "Last Thursday at 11:45 AM".
+		 * Similar to calendar in moment.js, but with time zone support.
+		 * @param {(string|number)} [zone=system] - 'system' (for browser-default time zone),
+		 * 'utc' (for UTC), or specify a time zone as number of minutes past UTC
+		 * @returns {string}
+		 */
+		calendar(zone) {
+			// Zero out the hours, minutes, seconds and milliseconds - keeping only the date;
+			// find the difference. Note that setHours() returns the same thing as getTime().
+			var dateDiff = (new Date().setHours(0, 0, 0, 0) -
+				new Date(this).setHours(0, 0, 0, 0)) / 8.64e7;
+			switch (true) {
+				case dateDiff === 0:
+					return this.format(xdate.localeData.relativeTimes.thisDay, zone);
+				case dateDiff === 1:
+					return this.format(xdate.localeData.relativeTimes.prevDay, zone);
+				case dateDiff > 0 && dateDiff < 7:
+					return this.format(xdate.localeData.relativeTimes.pastWeek, zone);
+				case dateDiff === -1:
+					return this.format(xdate.localeData.relativeTimes.nextDay, zone);
+				case dateDiff < 0 && dateDiff > -7:
+					return this.format(xdate.localeData.relativeTimes.thisWeek, zone);
+				default:
+					return this.format(xdate.localeData.relativeTimes.other, zone);
+			}
+		}
+
+	}
+
+	xdate.localeData = {
+		months: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
+		monthsShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
+		days: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
+		daysShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
+		relativeTimes: {
+			thisDay: '[Today at] h:mm A',
+			prevDay: '[Yesterday at] h:mm A',
+			nextDay: '[Tomorrow at] h:mm A',
+			thisWeek: 'dddd [at] h:mm A',
+			pastWeek: '[Last] dddd [at] h:mm A',
+			other: 'YYYY-MM-DD'
+		}
+	};
+
+	// TODO: allow easier i18n
+	xdate.loadLocaleData = function(data) {
+		xdate.localeData = data;
+	};
+
+	/**
+	 * Get month name from month number (1-indexed)
+	 * @param {number} monthNum
+	 * @returns {string}
+	 */
+	xdate.getMonthName = function(monthNum) {
+		return xdate.localeData.months[monthNum - 1];
+	};
+
+	/**
+	 * Get abbreviated month name from month number (1-indexed)
+	 * @param {number} monthNum
+	 * @returns {string}
+	 */
+	xdate.getMonthNameAbbrev = function(monthNum) {
+		return xdate.localeData.monthsShort[monthNum - 1];
+	};
+
+	/**
+	 * Get day name from day number (1-indexed, starting from Sunday)
+	 * @param {number} dayNum
+	 * @returns {string}
+	 */
+	xdate.getDayName = function(dayNum) {
+		return xdate.localeData.days[dayNum - 1];
+	};
+
+	/**
+	 * Get abbreviated day name from day number (1-indexed, starting from Sunday)
+	 * @param {number} dayNum
+	 * @returns {string}
+	 */
+	xdate.getDayNameAbbrev = function(dayNum) {
+		return xdate.localeData.daysShort[dayNum - 1];
+	};
+
+	return xdate;
+
+};

tests/date.test.js

@@ -0,0 +1,33 @@
+const { bot, expect} = require('./test_base');
+
+describe('date', async function() {
+
+	it('date constructor', function() {
+		let mwTs = new bot.date('20120304050607');
+		expect(mwTs.getTime()).to.equal(new Date(2012, 2, 4, 5, 6, 7).getTime());
+
+		let mwSig = new bot.date('13:14, 3 August 2017 (UTC)');
+		expect(mwSig.getTime()).to.equal(new Date('13:14 3 August 2017 UTC').getTime());
+
+		expect(new bot.date()).to.be.instanceOf(Date);
+
+	});
+
+	it('formats dates', function() {
+		let date = new bot.date('2012-05-09');
+		expect(date.format('YYYY-MM-DD[T]HH:mm:ss[Z]')).to.equal('2012-05-09T00:00:00Z');
+		expect(date.format('YYYY-[MM]-DD[T]HH:mm:ss[Z]')).to.equal('2012-MM-09T00:00:00Z');
+	});
+
+	it('adds and subtracts dates', function() {
+		let date = new bot.date('2012-08-09');
+		date.add(1, 'day');
+		expect(date.getDate()).to.equal(new Date('2012-08-10').getDate());
+		date.subtract(1, 'day');
+		expect(date.getDate()).to.equal(new Date('2012-08-09').getDate());
+
+		date.add(2, 'days');
+		expect(date.getDate()).to.equal(new Date('2012-08-11').getDate());
+	});
+
+});