draft / expose function to convert calendar dates to iso8601

src/utils/convert-date.spec.ts

@@ -1,4 +1,4 @@
-import { convertFromIso8601 } from './convert-date'
+import { convertFromIso8601, convertToIso8601 } from './convert-date'
 
 describe('date conversion from gregorian', () => {
     describe('to ethiopic', () => {
@@ -37,9 +37,21 @@ describe('date conversion from gregorian', () => {
 
 // gregorian, ethiopic and nepali
 
-describe('date conversion from', () => {
+describe('date conversion to gregorian', () => {
     describe('ethiopic to gregorian', () => {
-        it('should convert a date', () => {})
+        it('should convert a date', () => {
+            const result = convertToIso8601('2016-09-15', 'ethiopic')
+            expect(result.year).toEqual(2024)
+            expect(result.month).toEqual(5)
+            expect(result.day).toEqual(23)
+        })
+        // it('should handle year / eraYear differences', () => {
+        //     const result = convertFromIso8601('2016-09-15', 'ethiopic')
+        //     expect(result.eraYear).toEqual(2016)
+        //     expect(result.year).toEqual(7516)
+        //     expect(result.month).toEqual(9)
+        //     expect(result.day).toEqual(15)
+        // })
         it('should convert a date if "ethiopian" is passed instad of "ethiopic"', () => {})
     })
     describe('nepali to gregorian', () => {

src/utils/convert-date.ts

@@ -15,3 +15,17 @@ export const convertFromIso8601: ConvertDateFn = (date, userCalendar) => {
 
     return Temporal.PlainDate.from(date).withCalendar(calendar)
 }
+
+export const convertToIso8601: ConvertDateFn = (date, userCalendar) => {
+    const calendar = getCustomCalendarIfExists(
+        dhis2CalendarsMap[userCalendar] ?? userCalendar
+    ) as SupportedCalendar
+
+    const result = Temporal.Calendar.from(calendar).dateFromFields({
+        year: 2016,
+        month: 9,
+        day: 23,
+    })
+
+    return result
+}