1 files changed, 65 insertions, 0 deletions
diff --git a/spec/frontend/lib/utils/datetime_utility_spec.js b/spec/frontend/lib/utils/datetime_utility_spec.js
index 5b1fdea058b..b0b0b028761 100644
--- a/spec/frontend/lib/utils/datetime_utility_spec.js
+++ b/spec/frontend/lib/utils/datetime_utility_spec.js
@@ -69,6 +69,34 @@ describe('Date time utils', () => {
     });
   });
 
+  describe('formatDateAsMonth', () => {
+    it('should format dash cased date properly', () => {
+      const formattedMonth = datetimeUtility.formatDateAsMonth(new Date('2020-06-28'));
+
+      expect(formattedMonth).toBe('Jun');
+    });
+
+    it('should format return the non-abbreviated month', () => {
+      const formattedMonth = datetimeUtility.formatDateAsMonth(new Date('2020-07-28'), {
+        abbreviated: false,
+      });
+
+      expect(formattedMonth).toBe('July');
+    });
+
+    it('should format date with slashes properly', () => {
+      const formattedMonth = datetimeUtility.formatDateAsMonth(new Date('07/23/2016'));
+
+      expect(formattedMonth).toBe('Jul');
+    });
+
+    it('should format ISO date properly', () => {
+      const formattedMonth = datetimeUtility.formatDateAsMonth('2016-07-23T00:00:00.559Z');
+
+      expect(formattedMonth).toBe('Jul');
+    });
+  });
+
   describe('formatDate', () => {
     it('should format date properly', () => {
       const formattedDate = datetimeUtility.formatDate(new Date('07/23/2016'));
@@ -654,6 +682,20 @@ describe('differenceInSeconds', () => {
   });
 });
 
+describe('differenceInMonths', () => {
+  const startDateTime = new Date('2019-07-17T00:00:00.000Z');
+
+  it.each`
+    startDate                               | endDate                                 | expected
+    ${startDateTime}                        | ${startDateTime}                        | ${0}
+    ${startDateTime}                        | ${new Date('2019-12-17T12:00:00.000Z')} | ${5}
+    ${startDateTime}                        | ${new Date('2021-02-18T00:00:00.000Z')} | ${19}
+    ${new Date('2021-02-18T00:00:00.000Z')} | ${startDateTime}                        | ${-19}
+  `('returns $expected for $endDate - $startDate', ({ startDate, endDate, expected }) => {
+    expect(datetimeUtility.differenceInMonths(startDate, endDate)).toBe(expected);
+  });
+});
+
 describe('differenceInMilliseconds', () => {
   const startDateTime = new Date('2019-07-17T00:00:00.000Z');
 
@@ -667,3 +709,26 @@ describe('differenceInMilliseconds', () => {
     expect(datetimeUtility.differenceInMilliseconds(startDate, endDate)).toBe(expected);
   });
 });
+
+describe('dateAtFirstDayOfMonth', () => {
+  const date = new Date('2019-07-16T12:00:00.000Z');
+
+  it('returns the date at the first day of the month', () => {
+    const startDate = datetimeUtility.dateAtFirstDayOfMonth(date);
+    const expectedStartDate = new Date('2019-07-01T12:00:00.000Z');
+
+    expect(startDate).toStrictEqual(expectedStartDate);
+  });
+});
+
+describe('datesMatch', () => {
+  const date = new Date('2019-07-17T00:00:00.000Z');
+
+  it.each`
+    date1   | date2                                   | expected
+    ${date} | ${new Date('2019-07-17T00:00:00.000Z')} | ${true}
+    ${date} | ${new Date('2019-07-17T12:00:00.000Z')} | ${false}
+  `('returns $expected for $date1 matches $date2', ({ date1, date2, expected }) => {
+    expect(datetimeUtility.datesMatch(date1, date2)).toBe(expected);
+  });
+});