Fix Unmarshal error

Fix Unmarshal error

json.go

@@ -113,7 +113,7 @@ func (t *DateTimeMilli) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = DateTimeMilli{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for DateTimeMilli struct.
@@ -135,7 +135,7 @@ func (t *DateTimeMicro) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = DateTimeMicro{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for DateTimeMicro struct.
@@ -157,7 +157,7 @@ func (t *DateTimeNano) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = DateTimeNano{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for DateTimeNano struct.
@@ -179,7 +179,7 @@ func (t *Date) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = Date{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for Date struct.
@@ -201,7 +201,7 @@ func (t *DateMilli) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = DateMilli{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for DateMilli struct.
@@ -223,7 +223,7 @@ func (t *DateMicro) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = DateMicro{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for DateMicro struct.
@@ -245,7 +245,7 @@ func (t *DateNano) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = DateNano{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for DateNano struct.
@@ -268,7 +268,7 @@ func (t *Timestamp) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = Timestamp{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for Timestamp struct.
@@ -291,7 +291,7 @@ func (t *TimestampMilli) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = TimestampMilli{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for TimestampMilli struct.
@@ -314,7 +314,7 @@ func (t *TimestampMicro) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = TimestampMicro{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for TimestampMicro struct.
@@ -337,7 +337,7 @@ func (t *TimestampNano) UnmarshalJSON(b []byte) error {
 	if c.Error == nil {
 		*t = TimestampNano{c}
 	}
-	return nil
+	return c.Error
 }
 
 // String implements the interface Stringer for TimestampNano struct.

json_test.go

@@ -45,9 +45,7 @@ func TestCarbon_MarshalJSON(t *testing.T) {
 		CreatedAt4:   TimestampNano{Parse("2025-08-05 13:14:15.999999999")},
 	}
 	data, err := json.Marshal(&person)
-	if err != nil {
-		assert.NotNil(t, err)
-	}
+	assert.Nil(t, err)
 	fmt.Printf("Person output by json:\n%s\n", data)
 }
 
@@ -70,9 +68,7 @@ func TestCarbon_UnmarshalJSON(t *testing.T) {
 	}`
 
 	err := json.Unmarshal([]byte(str), &person)
-	if err != nil {
-		assert.NotNil(t, err)
-	}
+	assert.Nil(t, err)
 	fmt.Printf("Json string parse to person:\n%+v\n", person)
 }
 
@@ -94,8 +90,6 @@ func TestError_Json(t *testing.T) {
 		"created_at4": 0
 	}`
 	err := json.Unmarshal([]byte(str), &person)
-	if err != nil {
-		assert.NotNil(t, err)
-	}
+	assert.NotNil(t, err)
 	fmt.Printf("Json string parse to person:\n%+v\n", person)
 }