cmd/enter: Set failing command as active in main parser

This commit fixes handling of the following two cases:

  1. pebble enter subcommand --help
  2. pebble enter help subcommand

Help messages are handled in main.go when the executed command returns
flags.Error{Type:flags.ErrHelp}. When we pass the subcommand's return
value back to the main parser, the error handling there will use the
currently active command to print the help message. The active command
is enter but we want to print the subcommands help message.

Whenever the subcommand returns an error value, set it as active command
in the main parser, so that the error handling there works with the
failing subcommand.

Author: woky

cmd/pebble/cmd_enter.go

@@ -47,6 +47,7 @@ type cmdEnter struct {
 	Positional struct {
 		Cmd []string `positional-arg-name:"<subcommand>"`
 	} `positional-args:"yes"`
+	parser *flags.Parser
 }
 
 func init() {
@@ -111,6 +112,7 @@ func (cmd *cmdEnter) Execute(args []string) error {
 	}
 
 	if _, err := parser.ParseArgs(cmd.Positional.Cmd); err != nil {
+		cmd.parser.Command.Active = parser.Command.Active
 		return err
 	}
 
@@ -133,7 +135,11 @@ func (cmd *cmdEnter) Execute(args []string) error {
 	}
 
 	if enterFlags&enterNoServiceManager != 0 {
-		return commander.Execute(extraArgs)
+		if err := commander.Execute(extraArgs); err != nil {
+			cmd.parser.Command.Active = parser.Command.Active
+			return err
+		}
+		return nil
 	}
 
 	if enterFlags&enterSilenceLogging != 0 && !cmd.Verbose {
@@ -160,6 +166,10 @@ func (cmd *cmdEnter) Execute(args []string) error {
 
 	err := commander.Execute(extraArgs)
 
+	if err != nil {
+		cmd.parser.Command.Active = parser.Command.Active
+	}
+
 	if err != nil || enterFlags&enterKeepServiceManager == 0 {
 		runStop()
 	}
@@ -170,3 +180,7 @@ func (cmd *cmdEnter) Execute(args []string) error {
 
 	return err
 }
+
+func (cmd *cmdEnter) setParser(parser *flags.Parser) {
+	cmd.parser = parser
+}

cmd/pebble/cmd_enter_test.go

@@ -99,7 +99,7 @@ func (s *PebbleSuite) TestEnterUnknownCommand(c *C) {
 	defer restore()
 
 	exitCode := pebble.PebbleMain()
-	c.Check(s.Stderr(), Equals, "error: unknown command \"foo\", see 'pebble help enter'.\n")
+	c.Check(s.Stderr(), Equals, "error: unknown command \"foo\", see 'pebble help'.\n")
 	c.Check(s.Stdout(), Equals, "")
 	c.Check(exitCode, Equals, 1)
 }
@@ -171,3 +171,63 @@ func (s *PebbleSuite) TestEnterExecReadServiceOutputFile(c *C) {
 	c.Check(s.Stdout(), Equals, "foo\ncat: msg2: No such file or directory\n")
 	c.Check(exitCode, Equals, 1)
 }
+
+func (s *PebbleSuite) TestEnterExecCommandHelpOption(c *C) {
+	cmd := []string{"pebble", "enter", "exec", "--help"}
+	restore := fakeArgs(cmd...)
+	defer restore()
+
+	exitCode := pebble.PebbleMain()
+	// stderr is written to stdout buffer because of "combine stderr" mode,
+	// see cmd/pebble/cmd_exec.go:163
+	c.Check(s.Stderr(), Equals, "")
+	stdout := s.Stdout()
+	c.Check(stdout, Matches, "^(?s)Usage:\n  pebble exec \\[exec-OPTIONS\\] <command>\n.*")
+	c.Check(stdout, Matches, "(?s).*\\bThe exec command runs a remote command and waits for it to finish\\..*")
+	c.Check(exitCode, Equals, 0)
+}
+
+func (s *PebbleSuite) TestEnterHelpCommandHelpOption(c *C) {
+	cmd := []string{"pebble", "enter", "help", "--help"}
+	restore := fakeArgs(cmd...)
+	defer restore()
+
+	exitCode := pebble.PebbleMain()
+	// stderr is written to stdout buffer because of "combine stderr" mode,
+	// see cmd/pebble/cmd_exec.go:163
+	c.Check(s.Stderr(), Equals, "")
+	stdout := s.Stdout()
+	c.Check(stdout, Matches, "^(?s)Usage:\n  pebble help \\[help-OPTIONS\\] \\[<command>\\.\\.\\.\\]\n.*")
+	c.Check(stdout, Matches, "(?s).*\\bThe help command displays information about commands\\..*")
+	c.Check(exitCode, Equals, 0)
+}
+
+func (s *PebbleSuite) TestEnterHelpCommandExecArg(c *C) {
+	cmd := []string{"pebble", "enter", "help", "exec"}
+	restore := fakeArgs(cmd...)
+	defer restore()
+
+	exitCode := pebble.PebbleMain()
+	// stderr is written to stdout buffer because of "combine stderr" mode,
+	// see cmd/pebble/cmd_exec.go:163
+	c.Check(s.Stderr(), Equals, "")
+	stdout := s.Stdout()
+	c.Check(stdout, Matches, "^(?s)Usage:\n  pebble exec \\[exec-OPTIONS\\] <command>\n.*")
+	c.Check(stdout, Matches, "(?s).*\\bThe exec command runs a remote command and waits for it to finish\\..*")
+	c.Check(exitCode, Equals, 0)
+}
+
+func (s *PebbleSuite) TestEnterHelpCommandHelpArg(c *C) {
+	cmd := []string{"pebble", "enter", "help", "help"}
+	restore := fakeArgs(cmd...)
+	defer restore()
+
+	exitCode := pebble.PebbleMain()
+	// stderr is written to stdout buffer because of "combine stderr" mode,
+	// see cmd/pebble/cmd_exec.go:163
+	c.Check(s.Stderr(), Equals, "")
+	stdout := s.Stdout()
+	c.Check(stdout, Matches, "^(?s)Usage:\n  pebble help \\[help-OPTIONS\\] \\[<command>\\.\\.\\.\\]\n.*")
+	c.Check(stdout, Matches, "(?s).*\\bThe help command displays information about commands\\..*")
+	c.Check(exitCode, Equals, 0)
+}