fix(restore): extract preValidateTableData to reduce cyclomatic complexity

pkg/modules/dump/restore.go

@@ -45,7 +45,7 @@ import (
 	"src.techknowlogick.com/xormigrate"
 )
 
-const maxConfigSize = 5 * 1024 * 1024    // 5 MB, should be largely enough
+const maxConfigSize = 5 * 1024 * 1024      // 5 MB, should be largely enough
 const maxDumpEntrySize = 500 * 1024 * 1024 // 500 MB
 
 // parseDbFileName validates and extracts the table name from a database dump filename.
@@ -180,26 +180,8 @@ func Restore(filename string, overrideConfig bool) error {
 
 	lastMigration := ms[len(ms)-2]
 
-	// Pre-validate all table data JSON before wiping to avoid leaving the database
+	if err := preValidateTableData(dbfiles); err != nil {
-	// in a destroyed state when the archive contains corrupted table data.
+		return err
-	for table, d := range dbfiles {
-		if table == "migration" {
-			continue
-		}
-		rc, err := d.Open()
-		if err != nil {
-			return fmt.Errorf("could not open table data for %s: %w", table, err)
-		}
-		var bufValidate bytes.Buffer
-		if _, err := bufValidate.ReadFrom(io.LimitReader(rc, maxDumpEntrySize)); err != nil {
-			rc.Close()
-			return fmt.Errorf("could not read table data for %s: %w", table, err)
-		}
-		rc.Close()
-		var test []map[string]interface{}
-		if err := json.Unmarshal(bufValidate.Bytes(), &test); err != nil {
-			return fmt.Errorf("invalid JSON in table data for %s: %w", table, err)
-		}
 	}
 
 	// Start by wiping everything - only after we've validated the archive
@@ -404,6 +386,32 @@ func restoreTableData(tables map[string]*zip.File) error {
 	return nil
 }
 
+// preValidateTableData checks that all table data JSON files in the archive
+// are parseable before wiping the database, to avoid leaving the database
+// in a destroyed state when the archive contains corrupted data.
+func preValidateTableData(dbfiles map[string]*zip.File) error {
+	for table, d := range dbfiles {
+		if table == "migration" {
+			continue
+		}
+		rc, err := d.Open()
+		if err != nil {
+			return fmt.Errorf("could not open table data for %s: %w", table, err)
+		}
+		var buf bytes.Buffer
+		if _, err := buf.ReadFrom(io.LimitReader(rc, maxDumpEntrySize)); err != nil {
+			rc.Close()
+			return fmt.Errorf("could not read table data for %s: %w", table, err)
+		}
+		rc.Close()
+		var test []map[string]interface{}
+		if err := json.Unmarshal(buf.Bytes(), &test); err != nil {
+			return fmt.Errorf("invalid JSON in table data for %s: %w", table, err)
+		}
+	}
+	return nil
+}
+
 func unmarshalFileToJSON(file *zip.File) (contents []map[string]interface{}, err error) {
 	rc, err := file.Open()
 	if err != nil {