Added method Num to errutil which returns number of errors

errutil/errutil.go

@@ -10,6 +10,7 @@ package errutil
 
 // Errors is struct for handling many errors at once
 type Errors struct {
+	num    int
 	errors []error
 }
 
@@ -24,13 +25,14 @@ func NewErrors() *Errors {
 
 // Add adds new error to slice
 func (e *Errors) Add(errs ...error) *Errors {
-	if errs == nil || len(errs) == 0 {
+	if errs == nil {
 		return e
 	}
 
 	for _, err := range errs {
 		if err != nil {
 			e.errors = append(e.errors, err)
+			e.num++
 		}
 	}
 
@@ -39,11 +41,11 @@ func (e *Errors) Add(errs ...error) *Errors {
 
 // Last return last error in slice
 func (e *Errors) Last() error {
-	if e.errors == nil || len(e.errors) == 0 {
+	if e.errors == nil || e.num == 0 {
 		return nil
 	}
 
-	return e.errors[len(e.errors)-1]
+	return e.errors[e.num-1]
 }
 
 // All return all errors in slice
@@ -61,5 +63,10 @@ func (e *Errors) HasErrors() bool {
 		return false
 	}
 
-	return len(e.errors) != 0
+	return e.num != 0
+}
+
+// Num return number of errors
+func (e *Errors) Num() int {
+	return e.num
 }

errutil/errutil_test.go

@@ -37,6 +37,7 @@ func (s *ErrSuite) TestPositive(c *C) {
 	errs.Add(errors.New("4"))
 	errs.Add(errors.New("5"))
 
+	c.Assert(errs.Num(), Equals, 5)
 	c.Assert(errs.All(), HasLen, 5)
 	c.Assert(errs.HasErrors(), Equals, true)
 	c.Assert(errs.Last(), DeepEquals, errors.New("5"))