Add MarshalJSON to xtime.Duration

xtime/time.go

@@ -18,6 +18,7 @@
 package xtime
 
 import (
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -92,6 +93,11 @@ func (d *Duration) UnmarshalJSON(bs []byte) error {
 	return nil
 }
 
+// MarshalJSON implements json.Marshaler - Converts duration to human-readable format (e.g., "2h", "30m")
+func (d Duration) MarshalJSON() ([]byte, error) {
+	return json.Marshal(time.Duration(d).String())
+}
+
 // MarshalMsg appends the marshaled form of the object to the provided
 // byte slice, returning the extended slice and any errors encountered.
 func (d Duration) MarshalMsg(bytes []byte) ([]byte, error) {

xtime/time_unmarshal_test.go

@@ -141,4 +141,22 @@ durationPointer: 168h0m1s
 	if string(yamlData) != expected {
 		t.Errorf("Expected:\n%s\nGot:\n%s", expected, string(yamlData))
 	}
+
+	jsonData, err := json.Marshal(&testData)
+	if err != nil {
+		t.Fatalf("Failed to marshal JSON: %v", err)
+	}
+	expectedJSON := `{"a":"1s","dur":"0s","durationPointer":"168h0m1s"}`
+	if string(jsonData) != expectedJSON {
+		t.Errorf("Expected:\n%s\nGot:\n%s", expectedJSON, string(jsonData))
+	}
+
+	// The marshaled JSON must be readable back by UnmarshalJSON.
+	var back testDuration
+	if err := json.Unmarshal(jsonData, &back); err != nil {
+		t.Fatalf("Failed to unmarshal JSON: %v", err)
+	}
+	if back.A != d1 || back.Dur != d2 || back.DurationPointer == nil || *back.DurationPointer != d3 {
+		t.Errorf("JSON round-trip mismatch: got %+v", back)
+	}
 }