Merge pull request #113 from wallyworld/use-utils-passthrougherror

#113

RcPassthroughError has been moved to utils repo. Delete the one from here and use the utils one instead.

README.md

@@ -67,7 +67,7 @@ func IsErrSilent(err error) bool
 IsErrSilent returns whether the error should be logged from cmd.Main.
 
 
-## func IsRcPassthroughError
+## func utils.IsRcPassthroughError
 ``` go
 func IsRcPassthroughError(err error) bool
 ```
@@ -92,7 +92,7 @@ by the callers of a command. This way the logged output can also
 be displayed otherwise, e.g. on the screen.
 
 
-## func NewRcPassthroughError
+## func utils.NewRcPassthroughError
 ``` go
 func NewRcPassthroughError(code int) error
 ```
@@ -628,7 +628,7 @@ Write formats and outputs the value as directed by the --format and
 
 
 
-## type RcPassthroughError
+## type utils.RcPassthroughError
 ``` go
 type RcPassthroughError struct {
     Code int

cmd.go

@@ -22,30 +22,6 @@ import (
 	"github.com/juju/utils/v4"
 )
 
-// RcPassthroughError indicates that a Juju plugin command exited with a
-// non-zero exit code. This error is used to exit with the return code.
-type RcPassthroughError struct {
-	Code int
-}
-
-// Error implements error.
-func (e *RcPassthroughError) Error() string {
-	return fmt.Sprintf("subprocess encountered error code %v", e.Code)
-}
-
-// IsRcPassthroughError returns whether the error is an RcPassthroughError.
-func IsRcPassthroughError(err error) bool {
-	_, ok := err.(*RcPassthroughError)
-	return ok
-}
-
-// NewRcPassthroughError creates an error that will have the code used at the
-// return code from the cmd.Main function rather than the default of 1 if
-// there is an error.
-func NewRcPassthroughError(code int) error {
-	return &RcPassthroughError{code}
-}
-
 // ErrSilent can be returned from Run to signal that Main should exit with
 // code 1 without producing error output.
 var ErrSilent = errors.New("cmd: error out silently")
@@ -55,7 +31,7 @@ func IsErrSilent(err error) bool {
 	if err == ErrSilent {
 		return true
 	}
-	if _, ok := err.(*RcPassthroughError); ok {
+	if utils.IsRcPassthroughError(err) {
 		return true
 	}
 	return false
@@ -466,8 +442,8 @@ func Main(c Command, ctx *Context, args []string) int {
 		return rc
 	}
 	if err := c.Run(ctx); err != nil {
-		if IsRcPassthroughError(err) {
-			return err.(*RcPassthroughError).Code
+		if utils.IsRcPassthroughError(err) {
+			return err.(*utils.RcPassthroughError).Code
 		}
 		if err != ErrSilent {
 			WriteError(ctx.Stderr, err)

cmd_test.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/juju/loggo/v2"
 	jc "github.com/juju/testing/checkers"
+	"github.com/juju/utils/v4"
 	gc "gopkg.in/check.v1"
 
 	"github.com/juju/gnuflag"
@@ -214,7 +215,7 @@ func (s *CmdSuite) TestZeroOrOneArgs(c *gc.C) {
 
 func (s *CmdSuite) TestIsErrSilent(c *gc.C) {
 	c.Assert(cmd.IsErrSilent(cmd.ErrSilent), gc.Equals, true)
-	c.Assert(cmd.IsErrSilent(cmd.NewRcPassthroughError(99)), gc.Equals, true)
+	c.Assert(cmd.IsErrSilent(utils.NewRcPassthroughError(99)), gc.Equals, true)
 	c.Assert(cmd.IsErrSilent(fmt.Errorf("noisy")), gc.Equals, false)
 }
 

supercommand.go

@@ -12,6 +12,7 @@ import (
 	"github.com/juju/errors"
 	"github.com/juju/gnuflag"
 	"github.com/juju/loggo/v2"
+	"github.com/juju/utils/v4"
 )
 
 var logger = loggo.GetLogger("cmd")
@@ -549,7 +550,7 @@ func (c *SuperCommand) Run(ctx *Context) error {
 		logger.Debugf("error stack: \n%v", errors.ErrorStack(err))
 
 		// Err has been logged above, we can make the err silent so it does not log again in cmd/main
-		if !IsRcPassthroughError(err) {
+		if !utils.IsRcPassthroughError(err) {
 			err = ErrSilent
 		}
 	} else {