fix: today/yesterday keywords failed on last/first day of month (#1336)

- Wasn't correctly calculating the yesterday/tomorrow dates
- Unit tests previously were failing when run on the last day of the
month
- Mock the system time for consistency in tests
- Add tests explicitly testing first and last day of month, year
- Fixes #1335

packages/jsapi-utils/src/DateUtils.test.ts

@@ -225,15 +225,68 @@ describe('parseDateRange', () => {
     ]);
   });
 
-  it('should return a range from today to tomorrow if text is "today"', () => {
-    const range = DateUtils.parseDateRange(dh, 'today', 'America/New_York');
-    const start = range[0];
-    const end = range[1];
-    if (start && end) {
+  describe('a range from today to tomorrow if text is keyword "today"', () => {
+    beforeEach(() => {
+      jest.useFakeTimers();
+    });
+
+    afterEach(() => {
+      jest.useRealTimers();
+    });
+
+    test.each([
+      [new Date(2023, 4, 15)],
+      [new Date(2023, 4, 1)],
+      [new Date(2023, 4, 31)],
+      [new Date(2023, 0, 1)],
+      [new Date(2023, 11, 31)],
+    ])('should work with keyword "today" for date %s', date => {
+      jest.setSystemTime(date);
+      const range = DateUtils.parseDateRange(dh, 'today', 'America/New_York');
+      const start = range[0];
+      const end = range[1];
       const startDate = start?.asDate();
       const endDate = end?.asDate();
+      expect(startDate).toEqual(date);
+      expect(endDate).toEqual(
+        new Date(date.getFullYear(), date.getMonth(), date.getDate() + 1)
+      );
       expect(dateDiffInMillisseconds(startDate, endDate)).toBe(MS_PER_DAY);
-    }
+    });
+  });
+
+  describe('a range from yesterday to today if text is keyword "yesterday"', () => {
+    beforeEach(() => {
+      jest.useFakeTimers();
+    });
+
+    afterEach(() => {
+      jest.useRealTimers();
+    });
+
+    test.each([
+      [new Date(2023, 4, 15)],
+      [new Date(2023, 4, 1)],
+      [new Date(2023, 4, 31)],
+      [new Date(2023, 0, 1)],
+      [new Date(2023, 11, 31)],
+    ])('should work with keyword "yesterday" for date %s', date => {
+      jest.setSystemTime(date);
+      const range = DateUtils.parseDateRange(
+        dh,
+        'yesterday',
+        'America/New_York'
+      );
+      const start = range[0];
+      const end = range[1];
+      const startDate = start?.asDate();
+      const endDate = end?.asDate();
+      expect(startDate).toEqual(
+        new Date(date.getFullYear(), date.getMonth(), date.getDate() - 1)
+      );
+      expect(endDate).toEqual(date);
+      expect(dateDiffInMillisseconds(startDate, endDate)).toBe(MS_PER_DAY);
+    });
   });
 
   it('should return null as the end range if text is "now"', () => {

packages/jsapi-utils/src/DateUtils.ts

@@ -278,25 +278,35 @@ export class DateUtils {
         now.getMonth(),
         now.getDate()
       );
-      const endDate = DateUtils.makeDateWrapper(
-        dh,
-        timeZone,
+      const tomorrow = new Date(
         now.getFullYear(),
         now.getMonth(),
         now.getDate() + 1
       );
+      const endDate = DateUtils.makeDateWrapper(
+        dh,
+        timeZone,
+        tomorrow.getFullYear(),
+        tomorrow.getMonth(),
+        tomorrow.getDate()
+      );
       return [startDate, endDate];
     }
 
     if (cleanText === 'yesterday') {
       const now = new Date(Date.now());
-      const startDate = DateUtils.makeDateWrapper(
-        dh,
-        timeZone,
+      const yesterday = new Date(
         now.getFullYear(),
         now.getMonth(),
         now.getDate() - 1
       );
+      const startDate = DateUtils.makeDateWrapper(
+        dh,
+        timeZone,
+        yesterday.getFullYear(),
+        yesterday.getMonth(),
+        yesterday.getDate()
+      );
       const endDate = DateUtils.makeDateWrapper(
         dh,
         timeZone,