[-] return ignored error for QueryRow().Scan(), fixes #209 (#211)

batch_test.go

@@ -22,7 +22,7 @@ func TestBatch(t *testing.T) {
 	// run the test
 	batch := &pgx.Batch{}
 	batch.Queue("select 1 + 1").QueryRow(func(row pgx.Row) error {
-		var n int32
+		var n int
 		return row.Scan(&n)
 	})
 	batch.Queue("update users set active = $1 where id = $2", true, 1).Exec(func(ct pgconn.CommandTag) (err error) {

rows.go

@@ -3,6 +3,7 @@ package pgxmock
 import (
 	"encoding/csv"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"reflect"
 	"strings"
@@ -46,10 +47,8 @@ func (r *connRow) Scan(dest ...any) (err error) {
 		}
 		return rows.Err()
 	}
-
-	_ = rows.Scan(dest...)
-	rows.Close()
-	return rows.Err()
+	defer rows.Close()
+	return errors.Join(rows.Scan(dest...), rows.Err())
 }
 
 type rowSets struct {

rows_test.go

@@ -749,3 +749,39 @@ func TestConnRow(t *testing.T) {
 
 	a.NoError(mock.ExpectationsWereMet())
 }
+
+func TestInvalidsQueryRow(t *testing.T) {
+	mock, _ := NewPool()
+	a := assert.New(t)
+
+	// check invalid argument type
+	mock.ExpectQuery("SELECT").WillReturnRows(mock.NewRows([]string{"seq"}).AddRow("not-an-int"))
+	var expectedInt int
+	err := mock.QueryRow(ctx, "SELECT").Scan(&expectedInt)
+	a.Error(err)
+
+	// check BOF error
+	rs := mock.NewRows([]string{"seq"})
+	rs.AddRow("not-an-int").RowError(-1, errors.New("error")) // emulate pre-Next() error
+	mock.ExpectQuery("SELECT").WillReturnRows(rs)
+	err = mock.QueryRow(ctx, "SELECT").Scan(&expectedInt)
+	a.Error(err)
+
+	// check no row error
+	rs = mock.NewRows([]string{"seq"})
+	mock.ExpectQuery("SELECT").WillReturnRows(rs)
+	err = mock.QueryRow(ctx, "SELECT").Scan(&expectedInt)
+	a.Error(err)
+
+	//check first row error
+	rs = mock.NewRows([]string{"seq"}).RowError(0, errors.New("error"))
+	mock.ExpectQuery("SELECT").WillReturnRows(rs)
+	err = mock.QueryRow(ctx, "SELECT").Scan(&expectedInt)
+	a.Error(err)
+
+	// check pgtype.DriverBytes error
+	mock.ExpectQuery("SELECT").WillReturnRows(mock.NewRows([]string{"seq"}).AddRow("not-an-int"))
+	var d pgtype.DriverBytes
+	err = mock.QueryRow(ctx, "SELECT").Scan(&d)
+	a.Error(err)
+}