Tweak dbutil.ScanJSON to work with sql.Row as well as sql.Rows

dbutil/scan.go

@@ -10,29 +10,33 @@ import (
 
 var validate = validator.New()
 
+// Scanable is an interface to allow scanning of sql.Row or sql.Rows
+type Scannable interface {
+	Scan(dest ...any) error
+}
+
 // ScanJSON scans a row which is JSON into a destination struct
-func ScanJSON(rows *sql.Rows, destination any) error {
+func ScanJSON(src Scannable, dest any) error {
 	var raw json.RawMessage
-	err := rows.Scan(&raw)
-	if err != nil {
+
+	if err := src.Scan(&raw); err != nil {
 		return fmt.Errorf("error scanning row JSON: %w", err)
 	}
 
-	err = json.Unmarshal(raw, destination)
-	if err != nil {
+	if err := json.Unmarshal(raw, dest); err != nil {
 		return fmt.Errorf("error unmarshalling row JSON: %w", err)
 	}
 
 	return nil
 }
 
 // ScanAndValidateJSON scans a row which is JSON into a destination struct and validates it
-func ScanAndValidateJSON(rows *sql.Rows, destination any) error {
-	if err := ScanJSON(rows, destination); err != nil {
+func ScanAndValidateJSON(src Scannable, dest any) error {
+	if err := ScanJSON(src, dest); err != nil {
 		return err
 	}
 
-	err := validate.Struct(destination)
+	err := validate.Struct(dest)
 	if err != nil {
 		return fmt.Errorf("error validating unmarsalled JSON: %w", err)
 	}

dbutil/scan_test.go

@@ -96,6 +96,12 @@ func TestScanJSON(t *testing.T) {
 
 	rows.Close()
 
+	// can also scan as a single row
+	row := db.QueryRowContext(ctx, `SELECT ROW_TO_JSON(r) FROM (SELECT f.uuid, f.name, f.age FROM foo f WHERE id = 3) r`)
+	err = dbutil.ScanJSON(row, f)
+	assert.NoError(t, err)
+	assert.Equal(t, "a5850c89-dd29-46f6-9de1-d068b3c2db94", f.UUID)
+
 	// can all scan all rows with ScanAllJSON
 	rows = queryRows(`SELECT ROW_TO_JSON(r) FROM (SELECT f.uuid, f.name, f.age FROM foo f) r`)