Add some range checks for invalid parsha names and year numbers

src/parshaHaShavua.ts

@@ -14,7 +14,7 @@ export function getTriennialForParshaHaShavua(
   if (!(ev instanceof Event)) {
     throw new TypeError(`Bad event argument: ${ev}`);
   } else if (ev.getFlags() !== flags.PARSHA_HASHAVUA) {
-    throw new TypeError(`Event must be parsha hashavua: ${ev.getDesc()}`);
+    throw new TypeError(`Bad event argument: ${ev.getDesc()}`);
   }
   const hd = ev.getDate();
   const hyear0 = hd.getFullYear();

src/triennial.ts

@@ -136,8 +136,15 @@ export class Triennial {
    * @returns result, including a map of aliyot 1-7 plus "M"
    */
   getReading(parsha: string, yearNum: number): TriennialAliyot {
+    if (yearNum < 0 || yearNum > 2) {
+      throw new RangeError(`invalid year number: ${yearNum}`);
+    }
+    const years = this.readings.get(parsha);
+    if (!years) {
+      throw new RangeError(`invalid parsha: ${parsha}`);
+    }
     // don't use clone() here because we want to preserve HDate objects
-    const reading0 = this.readings.get(parsha)![yearNum];
+    const reading0 = years[yearNum];
     const reading: TriennialAliyot = {...reading0};
     if (reading.aliyot) {
       Object.values(reading.aliyot).map((aliyah: Aliyah) =>

test/parshaHaShavua.spec.js

@@ -1,4 +1,4 @@
-import {HebrewCalendar, HDate, months, flags, ParshaEvent} from '@hebcal/core';
+import {HebrewCalendar, HDate, months, flags, ParshaEvent, Event} from '@hebcal/core';
 import {getTriennialForParshaHaShavua} from '../src/parshaHaShavua';
 import {formatAliyahWithBook} from '@hebcal/leyning';
 
@@ -257,3 +257,11 @@ test('no-triennial-haft-on-special', () => {
   expect(reading.haftara).not.toBeDefined();
   expect(reading.haftaraNumV).not.toBeDefined();
 });
+
+test('getTriennialForParshaHaShavua-throws', () => {
+  const hd = new HDate(29, 'Tishrei', 5784);
+  const ev = new Event(hd, 'Bogus', flags.DAF_YOMI);
+  expect(() => {
+    getTriennialForParshaHaShavua(ev, false);
+  }).toThrow('Bad event argument: Bogus');
+});

test/triennial.spec.js

@@ -227,3 +227,20 @@ test('Yitro', () => {
   expect(reading2.aliyot).toEqual(expected23);
   expect(reading3.aliyot).toEqual(expected23);
 });
+
+test('getReading-throws', () => {
+  const tri = new Triennial(5780);
+  expect(() => {
+    tri.getReading('Noach', 3);
+  }).toThrow('invalid year number: 3');
+
+  expect(() => {
+    tri.getReading('Bogus', 1);
+  }).toThrow('invalid parsha: Bogus');
+});
+
+test('getYearNumber-throws', () => {
+  expect(() => {
+    Triennial.getYearNumber(1234);
+  }).toThrow('Invalid Triennial year 1234');
+});