feat: address review comments

Signed-off-by: Manan Gupta <[email protected]>

go/vt/vttablet/tabletserver/connpool/dbconn.go

@@ -166,7 +166,7 @@ func (dbc *Conn) execOnce(ctx context.Context, query string, maxrows int, wantfi
 	// Check if the context is already past its deadline before
 	// trying to execute the query.
 	if err := ctx.Err(); err != nil {
-		return nil, vterrors.Errorf(vtrpcpb.Code_CANCELED, "%s, before execution started", dbc.getErrorMessageFromContextError(ctx))
+		return nil, vterrors.Errorf(vtrpcpb.Code_CANCELED, "%s before execution started", dbc.getErrorMessageFromContextError(ctx))
 	}
 
 	now := time.Now()
@@ -235,7 +235,7 @@ func (dbc *Conn) FetchNext(ctx context.Context, maxrows int, wantfields bool) (*
 	// Check if the context is already past its deadline before
 	// trying to fetch the next result.
 	if err := ctx.Err(); err != nil {
-		return nil, vterrors.Errorf(vtrpcpb.Code_CANCELED, "%s, before reading next result set", dbc.getErrorMessageFromContextError(ctx))
+		return nil, vterrors.Errorf(vtrpcpb.Code_CANCELED, "%s before reading next result set", dbc.getErrorMessageFromContextError(ctx))
 	}
 	res, _, _, err := dbc.conn.ReadQueryResult(maxrows, wantfields)
 	if err != nil {

go/vt/vttablet/tabletserver/connpool/dbconn_test.go

@@ -199,7 +199,7 @@ func TestDBConnDeadline(t *testing.T) {
 
 	_, err = dbConn.Exec(ctx, sql, 1, false)
 	require.Error(t, err)
-	require.ErrorContains(t, err, "(errno 3024) (sqlstate HY000): Query execution was interrupted, maximum statement execution time exceeded, before execution started")
+	require.ErrorContains(t, err, "(errno 3024) (sqlstate HY000): Query execution was interrupted, maximum statement execution time exceeded before execution started")
 
 	compareTimingCounts(t, "PoolTest.Exec", 0, startCounts, mysqlTimings.Counts())
 
@@ -455,7 +455,10 @@ func TestDBNoPoolConnKill(t *testing.T) {
 	db.EnableConnFail()
 	err = dbConn.Kill("test kill", 0)
 	require.Error(t, err)
-	require.ErrorContains(t, err, "errno 2013")
+	var sqlErr *sqlerror.SQLError
+	isSqlErr := errors.As(sqlerror.NewSQLErrorFromError(err), &sqlErr)
+	require.True(t, isSqlErr)
+	require.EqualValues(t, sqlerror.CRServerLost, sqlErr.Number())
 	db.DisableConnFail()
 
 	// Kill succeed