chore: Optimize StartOfWeek and EndOfWeek methods

Author: kuafuRace

boundary.go

@@ -106,8 +106,11 @@ func (c *Carbon) StartOfWeek() *Carbon {
 	if c.IsInvalid() {
 		return c
 	}
-	dayOfWeek, weekStartsAt := c.DayOfWeek(), int(c.weekStartsAt)
-	return c.SubDays((DaysPerWeek + dayOfWeek - weekStartsAt) % DaysPerWeek).StartOfDay()
+	dayOfWeek, weekStartsAt := c.StdTime().Weekday(), c.WeekStartsAt()
+	if dayOfWeek == weekStartsAt {
+		return c.StartOfDay()
+	}
+	return c.SubDays(int(DaysPerWeek+dayOfWeek-weekStartsAt) % DaysPerWeek).StartOfDay()
 }
 
 // EndOfWeek returns a Carbon instance for end of the week.
@@ -116,8 +119,11 @@ func (c *Carbon) EndOfWeek() *Carbon {
 	if c.IsInvalid() {
 		return c
 	}
-	dayOfWeek, weekEndsAt := c.DayOfWeek(), int(c.weekStartsAt)+DaysPerWeek-1
-	return c.AddDays((DaysPerWeek - dayOfWeek + weekEndsAt) % DaysPerWeek).EndOfDay()
+	dayOfWeek, weekEndsAt := c.StdTime().Weekday(), c.WeekEndsAt()
+	if dayOfWeek == weekEndsAt {
+		return c.EndOfDay()
+	}
+	return c.AddDays(int(DaysPerWeek-dayOfWeek+weekEndsAt) % DaysPerWeek).EndOfDay()
 }
 
 // StartOfDay returns a Carbon instance for start of the day.

boundary_example_test.go

@@ -143,10 +143,10 @@ func ExampleCarbon_StartOfWeek() {
 	fmt.Println(carbon.Parse("2020-12-31 23:59:59").StartOfWeek().ToString())
 
 	// Output:
-	// 0000-12-31 00:00:00 +0000 UTC
-	// 2019-12-29 00:00:00 +0000 UTC
-	// 2020-08-09 00:00:00 +0000 UTC
-	// 2020-12-27 00:00:00 +0000 UTC
+	// 0001-01-01 00:00:00 +0000 UTC
+	// 2019-12-30 00:00:00 +0000 UTC
+	// 2020-08-10 00:00:00 +0000 UTC
+	// 2020-12-28 00:00:00 +0000 UTC
 }
 
 func ExampleCarbon_EndOfWeek() {
@@ -156,10 +156,10 @@ func ExampleCarbon_EndOfWeek() {
 	fmt.Println(carbon.Parse("2020-12-31 23:59:59").EndOfWeek().ToString())
 
 	// Output:
-	// 0001-01-06 23:59:59.999999999 +0000 UTC
-	// 2020-01-04 23:59:59.999999999 +0000 UTC
-	// 2020-08-15 23:59:59.999999999 +0000 UTC
-	// 2021-01-02 23:59:59.999999999 +0000 UTC
+	// 0001-01-07 23:59:59.999999999 +0000 UTC
+	// 2020-01-05 23:59:59.999999999 +0000 UTC
+	// 2020-08-16 23:59:59.999999999 +0000 UTC
+	// 2021-01-03 23:59:59.999999999 +0000 UTC
 }
 
 func ExampleCarbon_StartOfDay() {

boundary_unit_test.go

@@ -201,6 +201,7 @@ func TestCarbon_StartOfWeek(t *testing.T) {
 		assert.Equal(t, "2019-12-30 00:00:00 +0000 UTC", Parse("2020-01-01 00:00:00").StartOfWeek().ToString())
 		assert.Equal(t, "2020-08-10 00:00:00 +0000 UTC", Parse("2020-08-15 12:30:30").StartOfWeek().ToString())
 		assert.Equal(t, "2020-12-28 00:00:00 +0000 UTC", Parse("2020-12-31 23:59:59").StartOfWeek().ToString())
+		assert.Equal(t, "2025-04-07 00:00:00 +0000 UTC", Parse("2025-04-07 00:00:00").StartOfWeek().ToString())
 	})
 }
 
@@ -219,6 +220,7 @@ func TestCarbon_EndOfWeek(t *testing.T) {
 		assert.Equal(t, "2020-01-05 23:59:59.999999999 +0000 UTC", Parse("2020-01-01 00:00:00").EndOfWeek().ToString())
 		assert.Equal(t, "2020-08-16 23:59:59.999999999 +0000 UTC", Parse("2020-08-15 12:30:30").EndOfWeek().ToString())
 		assert.Equal(t, "2021-01-03 23:59:59.999999999 +0000 UTC", Parse("2020-12-31 23:59:59").EndOfWeek().ToString())
+		assert.Equal(t, "2025-04-13 23:59:59.999999999 +0000 UTC", Parse("2025-04-13 00:00:00").EndOfWeek().ToString())
 	})
 }