Use enums for status field

listener/internal/api/types/types.go

@@ -13,9 +13,18 @@ type SignatureRequestDecoded struct {
 	SignatureRequest
 }
 
+type Status string
+
+// create enum with status
+const (
+	Unknown  Status = "unknown"
+	Active   Status = "active"
+	Inactive Status = "inactive"
+)
+
 type SignatureRequestDecodedWithActive struct {
 	SignatureRequestDecoded
-	Status string `json:"status"` // "unknown" | "active" | "inactive"
+	Status Status `json:"status"` // "unknown" | "active" | "inactive"
 }
 
 type DecodedPayload struct {

listener/internal/api/validation/GetActiveValidators.go

@@ -110,7 +110,7 @@ func GetActiveValidators(requestsDecoded []types.SignatureRequestDecoded, beacon
 		if _, isActive := activeValidatorMap[req.Pubkey]; isActive {
 			activeValidators = append(activeValidators, types.SignatureRequestDecodedWithActive{
 				SignatureRequestDecoded: req,
-				Status:                  "active",
+				Status:                  types.Active,
 			})
 		} else {
 			// do not append inactive validators
@@ -127,7 +127,7 @@ func GetSignatureRequestsDecodedWithUnknown(requests []types.SignatureRequestDec
 	for _, req := range requests {
 		signatureRequestsDecodedWithActive = append(signatureRequestsDecodedWithActive, types.SignatureRequestDecodedWithActive{
 			SignatureRequestDecoded: req,
-			Status:                  "unknown",
+			Status:                  types.Unknown,
 		})
 	}
 	return signatureRequestsDecodedWithActive

listener/internal/api/validation/VerifySignature_test.go

@@ -46,7 +46,7 @@ func TestVerifySignature(t *testing.T) {
 				Network:   "mainnet",
 				Tag:       "solo"},
 		},
-		Status: "active",
+		Status: types.Active,
 	}
 
 	// Validate the signature
@@ -93,7 +93,7 @@ func TestVerifySignatureError(t *testing.T) {
 				Tag:       "solo",
 			},
 		},
-		Status: "active",
+		Status: types.Active,
 	}
 
 	// Validate the signature