Modernize some JavaScript idioms

package.json

@@ -61,23 +61,23 @@
     "verbose": true
   },
   "devDependencies": {
-    "@babel/core": "^7.23.0",
-    "@babel/preset-env": "^7.22.20",
+    "@babel/core": "^7.23.2",
+    "@babel/preset-env": "^7.23.2",
     "@babel/register": "^7.22.15",
     "@hebcal/solar-calc": "^1.1.2",
-    "@rollup/plugin-babel": "^6.0.3",
-    "@rollup/plugin-commonjs": "^25.0.4",
-    "@rollup/plugin-json": "^6.0.0",
-    "@rollup/plugin-node-resolve": "^15.2.1",
-    "@rollup/plugin-terser": "^0.4.3",
+    "@rollup/plugin-babel": "^6.0.4",
+    "@rollup/plugin-commonjs": "^25.0.7",
+    "@rollup/plugin-json": "^6.0.1",
+    "@rollup/plugin-node-resolve": "^15.2.3",
+    "@rollup/plugin-terser": "^0.4.4",
     "ava": "^5.3.1",
     "core-js": "^3.33.0",
-    "eslint": "^8.50.0",
+    "eslint": "^8.51.0",
     "eslint-config-google": "^0.14.0",
     "jsdoc": "^4.0.2",
     "jsdoc-to-markdown": "^8.0.0",
     "nyc": "^15.1.0",
-    "rollup": "^3.29.4",
+    "rollup": "^4.1.4",
     "ttag-cli": "^1.10.6"
   }
 }

src/HebrewDateEvent.js

@@ -23,7 +23,7 @@ export class HebrewDateEvent extends Event {
    * @return {string}
    */
   render(locale) {
-    const locale1 = locale && locale.toLowerCase();
+    const locale1 = locale?.toLowerCase();
     const locale0 = locale1 || Locale.getLocaleName();
     const hd = this.getDate();
     switch (locale0) {
@@ -50,7 +50,7 @@ export class HebrewDateEvent extends Event {
    * @return {string}
    */
   renderBrief(locale) {
-    const locale1 = locale && locale.toLowerCase();
+    const locale1 = locale?.toLowerCase();
     const locale0 = locale1 || Locale.getLocaleName();
     const hd = this.getDate();
     if (hd.getMonth() === months.TISHREI && hd.getDate() === 1) {

src/candles.js

@@ -193,7 +193,7 @@ export function makeFastStartEnd(ev, location) {
   if (desc === 'Erev Tish\'a B\'Av') {
     const sunset = zmanim.sunset();
     ev.startEvent = makeTimedEvent(hd, sunset, 'Fast begins', ev, location);
-  } else if (desc.substring(0, 11) === 'Tish\'a B\'Av') {
+  } else if (desc.startsWith('Tish\'a B\'Av')) {
     ev.endEvent = makeTimedEvent(hd, zmanim.tzeit(TZEIT_3MEDIUM_STARS), 'Fast ends', ev, location);
   } else {
     const dawn = zmanim.alotHaShachar();

src/event.js

@@ -228,8 +228,7 @@ export class Event {
    */
   getCategories() {
     const mask = this.getFlags();
-    for (let i = 0; i < flagToCategory.length; i++) {
-      const attrs = flagToCategory[i];
+    for (const attrs of flagToCategory) {
       if (mask & attrs[0]) {
         return attrs.slice(1);
       }

src/gematriya.js

@@ -80,8 +80,8 @@ export function gematriya(number) {
   const thousands = Math.floor(num / 1000);
   if (thousands > 0 && thousands !== 5) {
     const tdigits = num2digits(thousands);
-    for (let i = 0; i < tdigits.length; i++) {
-      str += num2heb[tdigits[i]];
+    for (const tdig of tdigits) {
+      str += num2heb[tdig];
     }
     str += GERESH;
   }
@@ -116,8 +116,8 @@ export function gematriyaStrToNum(str) {
     num += gematriyaStrToNum(thousands) * 1000;
     str = str.substring(gereshIdx);
   }
-  for (let i = 0; i < str.length; i++) {
-    const n = heb2num[str[i]];
+  for (const ch of str) {
+    const n = heb2num[ch];
     if (typeof n === 'number') {
       num += n;
     }

src/hdate.js

@@ -331,7 +331,7 @@ export class HDate {
     if (ofStr) {
       return ' ' + ofStr;
     }
-    if ('ashkenazi' === locale.substring(0, 9)) {
+    if (locale.startsWith('ashkenazi')) {
       return ' of';
     }
     return '';

src/hebcal.js

@@ -155,7 +155,7 @@ function checkCandleOptions(options) {
     return;
   }
   const location = options.location;
-  if (typeof location === 'undefined' || !location instanceof Location) {
+  if (typeof location === 'undefined' || !(location instanceof Location)) {
     throw new TypeError('options.candlelighting requires valid options.location');
   }
   if (typeof options.havdalahMins === 'number' && typeof options.havdalahDeg === 'number') {

src/holidays.spec.js

@@ -394,7 +394,7 @@ function eventDateDesc(ev) {
 
 test('9av-observed', (t) => {
   const events = HebrewCalendar.calendar({year: 2015, numYears: 10});
-  const av9 = events.filter((ev) => ev.getDesc().substring(0, 11) === 'Tish\'a B\'Av');
+  const av9 = events.filter((ev) => ev.getDesc().startsWith('Tish\'a B\'Av'));
   const actual = av9.map(eventDateBasenameDesc);
   const expected = [
     {date: '2015-07-26', basename: 'Tish\'a B\'Av', desc: 'Tish\'a B\'Av (observed)'},

src/locale.js

@@ -33,7 +33,7 @@ export class Locale {
    * @return {string}
    */
   static lookupTranslation(id, locale) {
-    const locale0 = locale && locale.toLowerCase();
+    const locale0 = locale?.toLowerCase();
     const loc = (typeof locale == 'string' && locales[locale0]) || activeLocale;
     const array = loc[id];
     if (array && array.length && array[0].length) {
@@ -153,7 +153,7 @@ export class Locale {
    * @return {string[]}
    */
   static getLocaleNames() {
-    return Object.keys(locales).sort();
+    return Object.keys(locales).sort((a, b) => a.localeCompare(b));
   }
 
   /**
@@ -162,7 +162,7 @@ export class Locale {
    * @return {string}
    */
   static ordinal(n, locale) {
-    const locale1 = locale && locale.toLowerCase();
+    const locale1 = locale?.toLowerCase();
     const locale0 = locale1 || activeName;
     if (!locale0) {
       return this.getEnOrdinal(n);

src/tachanun.js

@@ -139,8 +139,8 @@ function tachanunYear(year, il) {
       new HDate(14, months.IYYAR, year), // Pesach Sheini
   );
   return {
-    none: none.map((hd) => hd.abs()).sort(),
-    some: some.map((hd) => hd.abs()).sort(),
-    yesPrev: yesPrev.map((hd) => hd.abs()).sort(),
+    none: none.map((hd) => hd.abs()).sort((a, b) => a - b),
+    some: some.map((hd) => hd.abs()).sort((a, b) => a - b),
+    yesPrev: yesPrev.map((hd) => hd.abs()).sort((a, b) => a - b),
   };
 }