Fix end date for last periods (https://github.com/woocommerce/woocommerce-admin/pull/6584)

* Fix end date for last periods

* Test February end date for leap year

* Add changelog and testing instructions

* Handle feedback

* Fix merge conflict

* Add changelog

plugins/woocommerce-admin/TESTING-INSTRUCTIONS.md

@@ -11,6 +11,18 @@
 5. Click the Download button.
 6. Open the downloaded file and confirm the status values match the table.
 
+### Fix end date for last periods #6584
+1. Update your system clock to March 2021
+2. Create a completed order on 29th February 2020
+3. Go to Analytics > Revenue
+4. In the date range filter, select "Last Month" preset and compare to "Previous Year"
+5. Observe that 29th February sales are included
+6. In the date range filter, select "Last Week" preset and compare to "Previous Year"
+7. Observe that the end date is the same as the current year's end date
+8. In the date range filter, select "Last Quarter" preset and compare to "Previous Year"
+9. Observe that the end date is the same as the selected quarter and subtract 1 year
+10. In the date range filter, select "Last Year" preset and compare to "Previous Year"
+11. Observe that the end date is the same as the selected year and subtract 1 year
 ## 2.5.0
 
 ### Fix WC Home crash when the Analytics is disabled #7339
@@ -84,7 +96,6 @@ Please make sure to test it on Safari as well.
 5. Click on "Set up Tax" option on Task list.
 6. TOS should not blink. 
 
-
 ### Use saved values if available when switching tabs #7226
 
 1. Start onboarding wizard and continue to step 4.

plugins/woocommerce-admin/changelogs/fix-6471

@@ -0,0 +1,4 @@
+Significance: patch
+Type: Fix
+
+Fix end date for last periods

plugins/woocommerce-admin/packages/date/src/index.js

@@ -173,9 +173,12 @@ export function getLastPeriod( period, compare ) {
 			secondaryEnd = primaryStart.clone().subtract( 1, 'days' );
 			secondaryStart = secondaryEnd.clone().subtract( daysDiff, 'days' );
 		}
-	} else {
+	} else if ( period === 'week' ) {
 		secondaryStart = primaryStart.clone().subtract( 1, 'years' );
 		secondaryEnd = primaryEnd.clone().subtract( 1, 'years' );
+	} else {
+		secondaryStart = primaryStart.clone().subtract( 1, 'years' );
+		secondaryEnd = secondaryStart.clone().endOf( period );
 	}
 
 	// When the period is month, be sure to force end of month to take into account leap year

plugins/woocommerce-admin/packages/date/src/test/index.js

@@ -579,6 +579,19 @@ describe( 'getLastPeriod', () => {
 				lastMonthkLastYearEnd.isSame( dateValue.secondaryEnd, 'day' )
 			).toBe( true );
 		} );
+
+		it( 'should return correct values on a leap year', () => {
+			// Mock the current time as a year and month after a leap year month, March 2021.
+			const dateNowSpy = jest
+				.spyOn( Date, 'now' )
+				.mockImplementation( () => 1615587095000 );
+
+			const dateValue = getLastPeriod( 'month', 'previous_year' );
+
+			expect( dateValue.secondaryEnd.date() ).toBe( 29 );
+
+			dateNowSpy.mockRestore();
+		} );
 	} );
 
 	describe( 'quarter', () => {