REMOVE ME: playground: Add test for Optional implementation

THIS WORKS GREAT!

1 files changed, 31 insertions, 3 deletions

diff --git a/playground/main.go b/playground/main.go
index 38b5f0d..8c67cc0 100644
--- a/playground/main.go
+++ b/playground/main.go
@@ -8,9 +8,35 @@ import (
 	"os"
 )
 
+type Optional[T any] struct {
+	Value  T
+	Exists bool
+}
+
+func (o *Optional[T]) UnmarshalJSON(data []byte) error {
+	var Temp *T
+
+	err := json.Unmarshal(data, &Temp)
+	if err != nil {
+		return err
+	}
+
+	if Temp == nil {
+		var empty T
+		o.Value = empty
+		o.Exists = false
+		return nil
+	}
+
+	o.Value = *Temp
+	o.Exists = true
+	return nil
+}
+
 type Testy struct {
-	Flag *bool     `json:"flag"`
-	Cake *[]string `json:"cake"`
+	Flag *bool            `json:"flag"`
+	Cake *[]string        `json:"cake"`
+	Opt  Optional[string] `json:"opt"`
 }
 
 const TEXT = `{
@@ -18,11 +44,13 @@ const TEXT = `{
 		"one",
 		"two",
 		"three"
-	]
+	],
+	"opt": "peter"
 }`
 
 const TEMPLATE = `Flag is: {{if .Flag}}{{.Flag}}{{else}}[none]{{end}}
 Cake is: {{if .Cake}}{{range .Cake}}{{.}} {{end}}{{else}}[none]{{end}}
+Opt is: {{if .Opt.Exists}}{{.Opt.Value}}{{else}}[none]{{end}}
 `
 
 func main() {