improve ofrep metadata handling

Signed-off-by: Kavindu Dodanduwa <[email protected]>

Author: Kavindu-Dodan

providers/ofrep/internal/evaluate/resolver.go

@@ -51,7 +51,7 @@ func (g *OutboundResolver) resolveSingle(ctx context.Context, key string, evalCt
 			resErr := of.NewGeneralResolutionError(fmt.Sprintf("error parsing the response: %v", err))
 			return nil, &resErr
 		}
-		return toSuccessDto(success), nil
+		return toSuccessDto(success)
 	case 400:
 		return nil, parseError400(rsp.Body)
 	case 401, 403:
@@ -145,15 +145,19 @@ type successDto struct {
 	Metadata map[string]interface{}
 }
 
-func toSuccessDto(e evaluationSuccess) *successDto {
-	m, _ := e.Metadata.(map[string]interface{})
+func toSuccessDto(e evaluationSuccess) (*successDto, *of.ResolutionError) {
+	m, ok := e.Metadata.(map[string]interface{})
+	if !ok {
+		resErr := of.NewParseErrorResolutionError("metadata must be a map of string keys and arbitrary values")
+		return nil, &resErr
+	}
 
 	return &successDto{
 		Value:    e.Value,
 		Reason:   e.Reason,
 		Variant:  e.Variant,
 		Metadata: m,
-	}
+	}, nil
 }
 
 type request struct {

providers/ofrep/internal/evaluate/resolver_test.go

@@ -28,6 +28,14 @@ var success = evaluationSuccess{
 	},
 }
 
+var successWithInvalidMetadata = evaluationSuccess{
+	Value:    true,
+	Key:      "flagA",
+	Reason:   string(of.StaticReason),
+	Variant:  "true",
+	Metadata: "metadata",
+}
+
 func TestSuccess200(t *testing.T) {
 	t.Run("success evaluation response", func(t *testing.T) {
 		successBytes, err := json.Marshal(success)
@@ -80,6 +88,23 @@ func TestSuccess200(t *testing.T) {
 
 		validateErrorCode(success, resolutionError, of.GeneralCode, t)
 	})
+
+	t.Run("invalid metadata results in a parsing error", func(t *testing.T) {
+		b, err := json.Marshal(successWithInvalidMetadata)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		resolver := OutboundResolver{client: mockOutbound{
+			rsp: http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewReader(b)),
+			},
+		}}
+		success, resolutionError := resolver.resolveSingle(context.Background(), "", make(map[string]interface{}))
+
+		validateErrorCode(success, resolutionError, of.ParseErrorCode, t)
+	})
 }
 
 func TestResolveGeneralErrors(t *testing.T) {