vendor/github.com/hashicorp/go-multierror/prefix.go

   1 package multierror
   2
   3 import (
   4         "fmt"
   5
   6         "github.com/hashicorp/errwrap"
   7 )
   8
   9 // Prefix is a helper function that will prefix some text
  10 // to the given error. If the error is a multierror.Error, then
  11 // it will be prefixed to each wrapped error.
  12 //
  13 // This is useful to use when appending multiple multierrors
  14 // together in order to give better scoping.
  15 func Prefix(err error, prefix string) error {
  16         if err == nil {
  17                 return nil
  18         }
  19
  20         format := fmt.Sprintf("%s {{err}}", prefix)
  21         switch err := err.(type) {
  22         case *Error:
  23                 // Typed nils can reach here, so initialize if we are nil
  24                 if err == nil {
  25                         err = new(Error)
  26                 }
  27
  28                 // Wrap each of the errors
  29                 for i, e := range err.Errors {
  30                         err.Errors[i] = errwrap.Wrapf(format, e)
  31                 }
  32
  33                 return err
  34         default:
  35                 return errwrap.Wrapf(format, err)
  36         }
  37 }