Replace plain-object caches with Maps

src/DailyLearning.js

@@ -1,5 +1,5 @@
 /** @private */
-const cals = Object.create(null);
+const cals = new Map();
 
 /**
  * Plug-ins for daily learning calendars such as Daf Yomi, Mishna Yomi, Nach Yomi, etc.
@@ -16,7 +16,7 @@ export class DailyLearning {
     if (typeof calendar !== 'function') {
       throw new TypeError(`Invalid calendar function: ${calendar}`);
     }
-    cals[name] = calendar;
+    cals.set(name, calendar);
   }
 
   /**
@@ -27,7 +27,7 @@ export class DailyLearning {
    * @return {Event}
    */
   static lookup(name, hd) {
-    const fn = cals[name];
+    const fn = cals.get(name);
     if (typeof fn === 'function') {
       return fn(hd);
     }

src/gematriya.js

@@ -25,10 +25,10 @@ const heb2num = {
   'ש': 300,
   'ת': 400,
 };
-const num2heb = {};
+const num2heb = new Map();
 Object.keys(heb2num).forEach((key) => {
   const val = heb2num[key];
-  num2heb[val] = key;
+  num2heb.set(val, key);
 });
 
 /**
@@ -81,19 +81,19 @@ export function gematriya(number) {
   if (thousands > 0 && thousands !== 5) {
     const tdigits = num2digits(thousands);
     for (const tdig of tdigits) {
-      str += num2heb[tdig];
+      str += num2heb.get(tdig);
     }
     str += GERESH;
   }
   const digits = num2digits(num % 1000);
   if (digits.length == 1) {
-    return str + num2heb[digits[0]] + GERESH;
+    return str + num2heb.get(digits[0]) + GERESH;
   }
   for (let i = 0; i < digits.length; i++) {
     if (i + 1 === digits.length) {
       str += GERSHAYIM;
     }
-    str += num2heb[digits[i]];
+    str += num2heb.get(digits[i]);
   }
   return str;
 }

src/getTimezoneOffset.js

@@ -1,12 +1,12 @@
-const _formatters = {};
+const _formatters = new Map();
 
 /**
  * @private
  * @param {string} tzid
  * @return {Intl.DateTimeFormat}
  */
 function getFormatter(tzid) {
-  const fmt = _formatters[tzid];
+  const fmt = _formatters.get(tzid);
   if (fmt) return fmt;
   const f = new Intl.DateTimeFormat('en-US', {
     year: 'numeric',
@@ -18,7 +18,7 @@ function getFormatter(tzid) {
     hour12: false,
     timeZone: tzid,
   });
-  _formatters[tzid] = f;
+  _formatters.set(tzid, f);
   return f;
 }
 

src/hebcal.js

@@ -72,7 +72,7 @@ const EREV = flags.EREV;
 const CHOL_HAMOED = flags.CHOL_HAMOED;
 const YOM_KIPPUR_KATAN = flags.YOM_KIPPUR_KATAN;
 
-const unrecognizedAlreadyWarned = Object.create(null);
+const unrecognizedAlreadyWarned = new Set();
 const RECOGNIZED_OPTIONS = {
   location: 1,
   year: 1,
@@ -114,9 +114,9 @@ const RECOGNIZED_OPTIONS = {
  */
 function warnUnrecognizedOptions(options) {
   Object.keys(options).forEach((k) => {
-    if (typeof RECOGNIZED_OPTIONS[k] === 'undefined' && !unrecognizedAlreadyWarned[k]) {
+    if (typeof RECOGNIZED_OPTIONS[k] === 'undefined' && !unrecognizedAlreadyWarned.has(k)) {
       console.warn(`Ignoring unrecognized HebrewCalendar option: ${k}`);
-      unrecognizedAlreadyWarned[k] = true;
+      unrecognizedAlreadyWarned.add(k);
     }
   });
 }
@@ -489,7 +489,7 @@ function observedInDiaspora(ev) {
   return ev.observedInDiaspora();
 }
 
-const yearArrayCache = Object.create(null);
+const yearArrayCache = new Map();
 
 /**
  * HebrewCalendar is the main interface to the `@hebcal/core` library.
@@ -811,7 +811,7 @@ export class HebrewCalendar {
    */
   static getHolidaysForYearArray(year, il) {
     const cacheKey = `${year}-${il ? 1 : 0}`;
-    let events = yearArrayCache[cacheKey];
+    let events = yearArrayCache.get(cacheKey);
     if (events) {
       return events;
     }
@@ -828,7 +828,7 @@ export class HebrewCalendar {
         events = events.concat(filtered);
       }
     }
-    yearArrayCache[cacheKey] = events;
+    yearArrayCache.set(cacheKey, events);
     return events;
   }
 

src/holidays.js

@@ -324,7 +324,7 @@ export function getSedra_(hyear, il) {
 
 const emojiIsraelFlag = {emoji: '🇮🇱'};
 const chanukahEmoji = '🕎';
-const yearCache = Object.create(null);
+const yearCache = new Map();
 
 const KEYCAP_DIGITS = [
   '0️⃣', '1️⃣', '2️⃣', '3️⃣', '4️⃣',
@@ -345,7 +345,7 @@ export function getHolidaysForYear_(year) {
   } else if (year < 1 || year > 32658) {
     throw new RangeError(`Hebrew year ${year} out of range 1-32658`);
   }
-  const cached = yearCache[year];
+  const cached = yearCache.get(year);
   if (cached) {
     return cached;
   }
@@ -547,7 +547,7 @@ export function getHolidaysForYear_(year) {
     add(new HolidayEvent(hd, 'Birkat Hachamah', MINOR_HOLIDAY, {emoji: '☀️'}));
   }
 
-  yearCache[year] = h;
+  yearCache.set(year, h);
   return h;
 }
 

src/locale.js

@@ -10,7 +10,7 @@ const alias = {
 };
 
 /** @private */
-const locales = Object.create(null);
+const locales = new Map();
 /** @private */
 let activeLocale = null;
 /** @private */
@@ -34,7 +34,7 @@ export class Locale {
    */
   static lookupTranslation(id, locale) {
     const locale0 = locale?.toLowerCase();
-    const loc = (typeof locale == 'string' && locales[locale0]) || activeLocale;
+    const loc = (typeof locale == 'string' && locales.get(locale0)) || activeLocale;
     const array = loc[id];
     if (array && array.length && array[0].length) {
       return array[0];
@@ -68,7 +68,7 @@ export class Locale {
     if (typeof data.contexts !== 'object' || typeof data.contexts[''] !== 'object') {
       throw new TypeError(`Locale '${locale}' invalid compact format`);
     }
-    locales[locale.toLowerCase()] = data.contexts[''];
+    locales.set(locale.toLowerCase(), data.contexts['']);
   }
 
   /**
@@ -82,7 +82,7 @@ export class Locale {
       throw new TypeError(`Invalid locale name: ${locale}`);
     }
     const locale0 = locale.toLowerCase();
-    const loc = locales[locale0];
+    const loc = locales.get(locale0);
     if (!loc) {
       throw new TypeError(`Unknown locale: ${locale}`);
     }
@@ -110,7 +110,7 @@ export class Locale {
       throw new TypeError(`Invalid locale name: ${locale}`);
     }
     const locale0 = locale.toLowerCase();
-    const loc = locales[locale0];
+    const loc = locales.get(locale0);
     if (!loc) {
       throw new TypeError(`Unknown locale: ${locale}`);
     }
@@ -131,7 +131,7 @@ export class Locale {
    */
   static useLocale(locale) {
     const locale0 = locale.toLowerCase();
-    const obj = locales[locale0];
+    const obj = locales.get(locale0);
     if (!obj) {
       throw new RangeError(`Locale '${locale}' not found`);
     }
@@ -153,7 +153,8 @@ export class Locale {
    * @return {string[]}
    */
   static getLocaleNames() {
-    return Object.keys(locales).sort((a, b) => a.localeCompare(b));
+    const keys = Array.from(locales.keys());
+    return keys.sort((a, b) => a.localeCompare(b));
   }
 
   /**

src/sedra.js

@@ -149,7 +149,7 @@ export class Sedra {
       }
       return new HDate(this.firstSaturday + (idx * 7));
     } else if (typeof parsha === 'string') {
-      const num = parsha2id[parsha];
+      const num = parsha2id.get(parsha);
       if (typeof num === 'number') {
         return this.find(num);
       } else if (parsha.indexOf('-') !== -1) {
@@ -169,8 +169,8 @@ export class Sedra {
                typeof parsha[0] === 'string' && typeof parsha[1] === 'string') {
       const p1 = parsha[0];
       const p2 = parsha[1];
-      const num1 = parsha2id[p1];
-      const num2 = parsha2id[p2];
+      const num1 = parsha2id.get(p1);
+      const num2 = parsha2id.get(p2);
       if (num2 === num1 + 1) {
         return this.find(-num1);
       } else {
@@ -297,10 +297,10 @@ export const parshiot = [
   'Ha\'azinu',
 ];
 
-const parsha2id = {};
+const parsha2id = new Map();
 for (let id = 0; id < parshiot.length; id++) {
   const name = parshiot[id];
-  parsha2id[name] = id;
+  parsha2id.set(name, id);
 }
 
 /**

src/tachanun.js

@@ -15,7 +15,7 @@ function range(start, end) {
   return arr;
 }
 
-const cache = Object.create(null);
+const cache = new Map();
 
 const NONE = {
   shacharit: false,
@@ -43,7 +43,11 @@ export function tachanun_(hdate, il) {
 function tachanun0(hdate, il, checkNext) {
   const year = hdate.getFullYear();
   const key = `${year}-${il ? 1 : 0}`;
-  const dates = cache[key] = cache[key] || tachanunYear(year, il);
+  const cached = cache.get(key);
+  const dates = cached || tachanunYear(year, il);
+  if (!cached) {
+    cache.set(key, dates);
+  }
   const abs = hdate.abs();
   if (dates.none.indexOf(abs) > -1) {
     return NONE;