fix: handle presto-go-client EOF as successful row iteration

The presto-go-client v1.0.0 returns a *presto.EOF (containing the
query ID) from rows.Err() after all rows are successfully consumed.
This was incorrectly treated as a real error, causing the presto
extractor to fail with the query ID as the error message.

Author: ravisuhag

plugins/extractors/presto/presto.go

@@ -4,11 +4,12 @@ import (
 	"context"
 	"database/sql"
 	_ "embed"
+	"errors"
 	"fmt"
 	"net/url"
 	"strings"
 
-	_ "github.com/prestodb/presto-go-client/presto" // presto driver
+	prestoClient "github.com/prestodb/presto-go-client/presto" // presto driver
 	"github.com/raystack/meteor/models"
 	v1beta2 "github.com/raystack/meteor/models/raystack/assets/v1beta2"
 	"github.com/raystack/meteor/plugins"
@@ -158,7 +159,7 @@ func (e *Extractor) getCatalogs(ctx context.Context) ([]string, error) {
 
 		catalogs = append(catalogs, catalog)
 	}
-	if err := rows.Err(); err != nil {
+	if err := rows.Err(); err != nil && !isPrestoEOF(err) {
 		return nil, fmt.Errorf("iterate over catalogs: %w", err)
 	}
 
@@ -215,13 +216,20 @@ func (*Extractor) extractColumns(ctx context.Context, db *sql.DB, catalog string
 			Description: comment.String,
 		})
 	}
-	if err := rows.Err(); err != nil {
+	if err := rows.Err(); err != nil && !isPrestoEOF(err) {
 		return nil, fmt.Errorf("iterate over columns: %w", err)
 	}
 
 	return result, nil
 }
 
+// isPrestoEOF returns true if err is a *presto.EOF, which the
+// presto-go-client returns after all rows have been successfully consumed.
+func isPrestoEOF(err error) bool {
+	var eof *prestoClient.EOF
+	return errors.As(err, &eof)
+}
+
 // isNullable returns true if the string is "YES"
 func isNullable(value string) bool {
 	return value == "YES"

plugins/sqlutil/sqlutils.go

@@ -3,13 +3,22 @@ package sqlutil
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 
+	prestoClient "github.com/prestodb/presto-go-client/presto"
 	log "github.com/raystack/salt/observability/logger"
 	"go.nhat.io/otelsql"
 	"go.opentelemetry.io/otel/attribute"
 )
 
+// isPrestoEOF returns true if the error is a *presto.EOF, which the
+// presto-go-client returns after all rows have been successfully consumed.
+func isPrestoEOF(err error) bool {
+	var eof *prestoClient.EOF
+	return errors.As(err, &eof)
+}
+
 func FetchDBs(ctx context.Context, db *sql.DB, logger log.Logger, query string) ([]string, error) {
 	res, err := db.QueryContext(ctx, query)
 	if err != nil {
@@ -27,7 +36,7 @@ func FetchDBs(ctx context.Context, db *sql.DB, logger log.Logger, query string)
 		dbs = append(dbs, database)
 
 	}
-	if err := res.Err(); err != nil {
+	if err := res.Err(); err != nil && !isPrestoEOF(err) {
 		return nil, fmt.Errorf("iterate rows: %w", err)
 	}
 	return dbs, nil
@@ -49,7 +58,7 @@ func FetchTablesInDB(ctx context.Context, db *sql.DB, dbName, query string) ([]s
 		}
 		tbls = append(tbls, table)
 	}
-	if err := rows.Err(); err != nil {
+	if err := rows.Err(); err != nil && !isPrestoEOF(err) {
 		return nil, fmt.Errorf("iterate rows: %w", err)
 	}