Update Required & Invalid logic

updated required validator to check for a nil value for types:
slice, map, pointer, interface, channel and function.
updated tranverseField to handle invalid field type.

 Changes to be committed:
	modified:   baked_in.go
	modified:   doc.go
	modified:   validator.go
	modified:   validator_test.go

baked_in.go

@@ -403,10 +403,8 @@ func isAlpha(topStruct reflect.Value, currentStruct reflect.Value, field reflect
 func hasValue(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
 
 	switch fieldKind {
-
+	case reflect.Slice, reflect.Map, reflect.Ptr, reflect.Interface, reflect.Chan, reflect.Func:
-	case reflect.Slice, reflect.Map, reflect.Array:
+		return !field.IsNil()
-		return !field.IsNil() && int64(field.Len()) > 0
-
 	default:
 		return field.IsValid() && field.Interface() != reflect.Zero(fieldType).Interface()
 	}

doc.go

@@ -123,9 +123,10 @@ Here is a list of the current built in validators:
 		required will be applied to string
 
 	required
-		This validates that the value is not the data types default value.
+		This validates that the value is not the data types default zero value.
 		For numbers ensures value is not zero. For strings ensures value is
-		not "". For slices, arrays, and maps, ensures the length is not zero.
+		not "". For slices, maps, pointers, interfaces, channels and functions
+		ensures the value is not nil.
 		(Usage: required)
 
 	len

validator.go

@@ -243,12 +243,10 @@ func (v *Validate) traverseField(topStruct reflect.Value, currentStruct reflect.
 		kind = current.Kind()
 	}
 
-	typ := current.Type()
-
 	// this also allows for tags 'required' and 'omitempty' to be used on
 	// nested struct fields because when len(tags) > 0 below and the value is nil
 	// then required failes and we check for omitempty just before that
-	if (kind == reflect.Ptr || kind == reflect.Interface) && current.IsNil() {
+	if ((kind == reflect.Ptr || kind == reflect.Interface) && current.IsNil()) || kind == reflect.Invalid {
 
 		if strings.Contains(tag, omitempty) {
 			return
@@ -264,19 +262,35 @@ func (v *Validate) traverseField(topStruct reflect.Value, currentStruct reflect.
 				param = vals[1]
 			}
 
+			if kind == reflect.Invalid {
+				errs[errPrefix+name] = &FieldError{
+					Field: name,
+					Tag:   vals[0],
+					Param: param,
+					Kind:  kind,
+				}
+				return
+			}
+
 			errs[errPrefix+name] = &FieldError{
 				Field: name,
 				Tag:   vals[0],
 				Param: param,
 				Value: current.Interface(),
 				Kind:  kind,
-				Type:  typ,
+				Type:  current.Type(),
 			}
 
 			return
 		}
+		// if we get here tag length is zero and we can leave
+		if kind == reflect.Invalid {
+			return
+		}
 	}
 
+	typ := current.Type()
+
 	switch kind {
 	case reflect.Struct, reflect.Interface:
 

validator_test.go

@@ -119,6 +119,79 @@ func AssertError(t *testing.T, errs ValidationErrors, key, field, expectedTag st
 	EqualSkip(t, 2, val.Tag, expectedTag)
 }
 
+func TestSliceMapArrayChanFuncPtrInterfaceRequiredValidation(t *testing.T) {
+
+	var m map[string]string
+
+	errs := validate.Field(m, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	m = map[string]string{}
+	errs = validate.Field(m, "required")
+	Equal(t, errs, nil)
+
+	var arr [5]string
+	errs = validate.Field(arr, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	arr[0] = "ok"
+	errs = validate.Field(arr, "required")
+	Equal(t, errs, nil)
+
+	var s []string
+	errs = validate.Field(s, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	s = []string{}
+	errs = validate.Field(s, "required")
+	Equal(t, errs, nil)
+
+	var c chan string
+	errs = validate.Field(c, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	c = make(chan string)
+	errs = validate.Field(c, "required")
+	Equal(t, errs, nil)
+
+	var tst *int
+	errs = validate.Field(tst, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	one := 1
+	tst = &one
+	errs = validate.Field(tst, "required")
+	Equal(t, errs, nil)
+
+	var iface interface{}
+
+	errs = validate.Field(iface, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	errs = validate.Field(iface, "omitempty,required")
+	Equal(t, errs, nil)
+
+	errs = validate.Field(iface, "")
+	Equal(t, errs, nil)
+
+	var f func(string)
+
+	errs = validate.Field(f, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	f = func(name string) {}
+
+	errs = validate.Field(f, "required")
+	Equal(t, errs, nil)
+}
+
 func TestDatePtrValidationIssueValidation(t *testing.T) {
 
 	type Test struct {
@@ -3262,14 +3335,14 @@ func TestStructSliceValidation(t *testing.T) {
 		Min:       []int{1, 2},
 		Max:       []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 0},
 		MinMax:    []int{1, 2, 3, 4, 5},
-		OmitEmpty: []int{},
+		OmitEmpty: nil,
 	}
 
 	errs := validate.Struct(tSuccess)
 	Equal(t, errs, nil)
 
 	tFail := &TestSlice{
-		Required:  []int{},
+		Required:  nil,
 		Len:       []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1},
 		Min:       []int{},
 		Max:       []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1},