use errors.Is() to check for errors (#1730)

Since go 1.13 you can wrap errors. This make it no longer possible to
compare with `==`, instead you have to compare with `errors.Is()`.

I noticed this problem because -h was no longer working after I stared
wrapping the errors in my custom FlagErrorFunc function.
Note that this is only a problem when a custom help flag is defined.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
This commit is contained in:
Paul Holzinger 2022-06-21 04:02:33 +02:00 committed by GitHub
parent ea94a3db55
commit b9ca5949e2
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2 changed files with 34 additions and 1 deletions

View file

@ -18,6 +18,7 @@ package cobra
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"os"
@ -990,7 +991,7 @@ func (c *Command) ExecuteC() (cmd *Command, err error) {
if err != nil {
// Always show help if requested, even if SilenceErrors is in
// effect
if err == flag.ErrHelp {
if errors.Is(err, flag.ErrHelp) {
cmd.HelpFunc()(cmd, args)
return cmd, nil
}

View file

@ -1723,6 +1723,38 @@ func TestFlagErrorFunc(t *testing.T) {
}
}
func TestFlagErrorFuncHelp(t *testing.T) {
c := &Command{Use: "c", Run: emptyRun}
c.PersistentFlags().Bool("help", false, "help for c")
c.SetFlagErrorFunc(func(_ *Command, err error) error {
return fmt.Errorf("wrap error: %w", err)
})
out, err := executeCommand(c, "--help")
if err != nil {
t.Errorf("--help should not fail: %v", err)
}
expected := `Usage:
c [flags]
Flags:
--help help for c
`
if out != expected {
t.Errorf("Expected: %v, got: %v", expected, out)
}
out, err = executeCommand(c, "-h")
if err != nil {
t.Errorf("-h should not fail: %v", err)
}
if out != expected {
t.Errorf("Expected: %v, got: %v", expected, out)
}
}
// TestSortedFlags checks,
// if cmd.LocalFlags() is unsorted when cmd.Flags().SortFlags set to false.
// Related to https://github.com/spf13/cobra/issues/404.