Merge pull request #12 from manicar2093/fix/recognize-empty-from-unma…

…rshall

fix: recognize empty from unmarshall

goption.go

@@ -21,8 +21,7 @@ func Empty[T any]() Optional[T] {
 
 // Of returns an Optional with the specified present value. It does not matters if value is nil
 func Of[T any](value T) Optional[T] {
-	_, isValid := isValidData(value)
-	return Optional[T]{value: value, isValidValue: isValid}
+	return Optional[T]{value: value, isValidValue: getIsValidDataBool(value)}
 }
 
 // Get when a value is present returns the value, otherwise throws ErrNoSuchElement.
@@ -80,3 +79,8 @@ func isValidData[T any](value T) (reflect.Value, bool) {
 		return val, !val.IsZero()
 	}
 }
+
+func getIsValidDataBool[T any](value T) bool {
+	_, is := isValidData(value)
+	return is
+}

json.go

@@ -3,14 +3,18 @@ package goption
 import (
 	"encoding/json"
 	"reflect"
+	"strconv"
 )
 
 func (c *Optional[T]) UnmarshalJSON(data []byte) error {
-	if string(data) == `"null"` {
-		c.isValidValue = false
-		return nil
+	unquoted, err := strconv.Unquote(string(data))
+	if err != nil {
+		return err
+	}
+	if unquoted == "null" {
+		unquoted = ""
 	}
-	c.isValidValue = len(data) > 0
+	c.isValidValue = getIsValidDataBool(unquoted)
 	if err := json.Unmarshal(data, &c.value); err != nil {
 		return err
 	}

json_test.go

@@ -46,6 +46,19 @@ var _ = Describe("Json", func() {
 				Expect(holder.IsPresent()).To(BeFalse())
 			})
 		})
+
+		When("is zero", func() {
+			It("creates an empty optional", func() {
+				var (
+					jsonData = []byte(`""`)
+					holder   = goption.Empty[string]()
+				)
+				err := holder.UnmarshalJSON(jsonData)
+
+				Expect(err).ToNot(HaveOccurred())
+				Expect(holder.IsPresent()).To(BeFalse())
+			})
+		})
 	})
 
 	Describe("MarshalJson", func() {