text: package matchers
  
  import (
  	"github.com/golang/mock/gomock"
  )
  
  func MatchesError(e error) gomock.Matcher {
  	return &errorMatcher{err: e}
  }
  
  type errorMatcher struct {
  	err error
  }
  
  func (e *errorMatcher) Matches(x interface{}) bool {
  	err, ok := x.(error)
  	if !ok {
  		return false
  	}
  	return err.Error() == e.err.Error()
  }
  
  func (e *errorMatcher) String() string {
  	return e.err.Error()
  }
  