correct interface issue

add handling of interface validation by determining it's type

for issue #85

validator.go

@@ -353,7 +353,6 @@ func (v *Validate) structRecursive(top interface{}, current interface{}, s inter
 		structName = structType.Name()
 		numFields = structValue.NumField()
 		cs = &cachedStruct{name: structName, children: numFields}
-		structCache.Set(structType, cs)
 	}
 
 	validationErrors := structPool.Borrow()
@@ -429,24 +428,62 @@ func (v *Validate) structRecursive(top interface{}, current interface{}, s inter
 					continue
 				}
 
-				if valueField.Kind() == reflect.Ptr && valueField.IsNil() {
+				if (valueField.Kind() == reflect.Ptr || cField.kind == reflect.Interface) && valueField.IsNil() {
 
 					if strings.Contains(cField.tag, omitempty) {
-						continue
+						goto CACHEFIELD
 					}
 
-					if strings.Contains(cField.tag, required) {
+					tags := strings.Split(cField.tag, tagSeparator)
+
+					if len(tags) > 0 {
+
+						var param string
+						vals := strings.SplitN(tags[0], tagKeySeparator, 2)
+
+						if len(vals) > 1 {
+							param = vals[1]
+						}
 
 						validationErrors.Errors[cField.name] = &FieldError{
 							Field: cField.name,
-							Tag:   required,
+							Tag:   vals[0],
+							Param: param,
 							Value: valueField.Interface(),
+							Kind:  valueField.Kind(),
+							Type:  valueField.Type(),
 						}
 
-						continue
+						goto CACHEFIELD
+					}
+				}
+
+				// if we get here, the field is interface and could be a struct or a field
+				// and we need to check the inner type and validate
+				if cField.kind == reflect.Interface {
+
+					valueField = valueField.Elem()
+
+					if valueField.Kind() == reflect.Ptr && !valueField.IsNil() {
+						valueField = valueField.Elem()
+					}
+
+					if valueField.Kind() == reflect.Struct {
+						goto VALIDATESTRUCT
+					}
+
+					// sending nil for cField as it was type interface and could be anything
+					// each time and so must be calculated each time and can't be cached reliably
+					if fieldError := v.fieldWithNameAndValue(top, current, valueField.Interface(), cField.tag, cField.name, false, nil); fieldError != nil {
+						validationErrors.Errors[fieldError.Field] = fieldError
+						// free up memory reference
+						fieldError = nil
 					}
+
+					goto CACHEFIELD
 				}
 
+			VALIDATESTRUCT:
 				if structErrors := v.structRecursive(top, valueField.Interface(), valueField.Interface()); structErrors != nil {
 					validationErrors.StructErrors[cField.name] = structErrors
 					// free up memory map no longer needed
@@ -486,11 +523,14 @@ func (v *Validate) structRecursive(top interface{}, current interface{}, s inter
 			}
 		}
 
+	CACHEFIELD:
 		if !isCached {
 			cs.fields = append(cs.fields, cField)
 		}
 	}
 
+	structCache.Set(structType, cs)
+
 	if len(validationErrors.Errors) == 0 && len(validationErrors.StructErrors) == 0 {
 		structPool.Return(validationErrors)
 		return nil
@@ -709,19 +749,29 @@ func (v *Validate) traverseMap(val interface{}, current interface{}, valueField
 				continue
 			}
 
-			if idxField.Kind() == reflect.Ptr && idxField.IsNil() {
+			if (idxField.Kind() == reflect.Ptr || idxField.Kind() == reflect.Interface) && idxField.IsNil() {
 
-				if strings.Contains(cField.tag, omitempty) {
+				if strings.Contains(cField.diveTag, omitempty) {
 					continue
 				}
 
-				if strings.Contains(cField.tag, required) {
+				tags := strings.Split(cField.diveTag, tagSeparator)
+
+				if len(tags) > 0 {
+
+					var param string
+					vals := strings.SplitN(tags[0], tagKeySeparator, 2)
+
+					if len(vals) > 1 {
+						param = vals[1]
+					}
 
 					errs[key.Interface()] = &FieldError{
 						Field: fmt.Sprintf(mapIndexFieldName, cField.name, key.Interface()),
-						Tag:   required,
+						Tag:   vals[0],
+						Param: param,
 						Value: idxField.Interface(),
-						Kind:  reflect.Ptr,
+						Kind:  idxField.Kind(),
 						Type:  cField.mapSubtype,
 					}
 				}
@@ -729,6 +779,30 @@ func (v *Validate) traverseMap(val interface{}, current interface{}, valueField
 				continue
 			}
 
+			// if we get here, the field is interface and could be a struct or a field
+			// and we need to check the inner type and validate
+			if idxField.Kind() == reflect.Interface {
+
+				idxField = idxField.Elem()
+
+				if idxField.Kind() == reflect.Ptr && !idxField.IsNil() {
+					idxField = idxField.Elem()
+				}
+
+				if idxField.Kind() == reflect.Struct {
+					goto VALIDATESTRUCT
+				}
+
+				// sending nil for cField as it was type interface and could be anything
+				// each time and so must be calculated each time and can't be cached reliably
+				if fieldError := v.fieldWithNameAndValue(val, current, idxField.Interface(), cField.diveTag, fmt.Sprintf(mapIndexFieldName, cField.name, key.Interface()), false, nil); fieldError != nil {
+					errs[key.Interface()] = fieldError
+				}
+
+				continue
+			}
+
+		VALIDATESTRUCT:
 			if structErrors := v.structRecursive(val, current, idxField.Interface()); structErrors != nil {
 				errs[key.Interface()] = structErrors
 			}
@@ -768,19 +842,29 @@ func (v *Validate) traverseSliceOrArray(val interface{}, current interface{}, va
 				continue
 			}
 
-			if idxField.Kind() == reflect.Ptr && idxField.IsNil() {
+			if (idxField.Kind() == reflect.Ptr || idxField.Kind() == reflect.Interface) && idxField.IsNil() {
 
-				if strings.Contains(cField.tag, omitempty) {
+				if strings.Contains(cField.diveTag, omitempty) {
 					continue
 				}
 
-				if strings.Contains(cField.tag, required) {
+				tags := strings.Split(cField.diveTag, tagSeparator)
+
+				if len(tags) > 0 {
+
+					var param string
+					vals := strings.SplitN(tags[0], tagKeySeparator, 2)
+
+					if len(vals) > 1 {
+						param = vals[1]
+					}
 
 					errs[i] = &FieldError{
 						Field: fmt.Sprintf(arrayIndexFieldName, cField.name, i),
-						Tag:   required,
+						Tag:   vals[0],
+						Param: param,
 						Value: idxField.Interface(),
-						Kind:  reflect.Ptr,
+						Kind:  idxField.Kind(),
 						Type:  cField.sliceSubtype,
 					}
 				}
@@ -788,6 +872,30 @@ func (v *Validate) traverseSliceOrArray(val interface{}, current interface{}, va
 				continue
 			}
 
+			// if we get here, the field is interface and could be a struct or a field
+			// and we need to check the inner type and validate
+			if idxField.Kind() == reflect.Interface {
+
+				idxField = idxField.Elem()
+
+				if idxField.Kind() == reflect.Ptr && !idxField.IsNil() {
+					idxField = idxField.Elem()
+				}
+
+				if idxField.Kind() == reflect.Struct {
+					goto VALIDATESTRUCT
+				}
+
+				// sending nil for cField as it was type interface and could be anything
+				// each time and so must be calculated each time and can't be cached reliably
+				if fieldError := v.fieldWithNameAndValue(val, current, idxField.Interface(), cField.diveTag, fmt.Sprintf(arrayIndexFieldName, cField.name, i), false, nil); fieldError != nil {
+					errs[i] = fieldError
+				}
+
+				continue
+			}
+
+		VALIDATESTRUCT:
 			if structErrors := v.structRecursive(val, current, idxField.Interface()); structErrors != nil {
 				errs[i] = structErrors
 			}

validator_test.go

@@ -226,6 +226,226 @@ func AssertMapFieldError(t *testing.T, s map[string]*FieldError, field string, e
 	EqualSkip(t, 2, val.Tag, expectedTag)
 }
 
+func TestInterfaceErrValidation(t *testing.T) {
+
+	var v1 interface{}
+	var v2 interface{}
+
+	v2 = 1
+	v1 = v2
+
+	err := validate.Field(v1, "len=1")
+	Equal(t, err, nil)
+	err = validate.Field(v2, "len=1")
+	Equal(t, err, nil)
+
+	type ExternalCMD struct {
+		Userid string      `json:"userid"`
+		Action uint32      `json:"action"`
+		Data   interface{} `json:"data,omitempty" validate:"required"`
+	}
+
+	s := &ExternalCMD{
+		Userid: "123456",
+		Action: 10000,
+		// Data:   1,
+	}
+
+	errs := validate.Struct(s)
+	NotEqual(t, errs, nil)
+	Equal(t, errs.Errors["Data"].Field, "Data")
+	Equal(t, errs.Errors["Data"].Tag, "required")
+
+	type ExternalCMD2 struct {
+		Userid string      `json:"userid"`
+		Action uint32      `json:"action"`
+		Data   interface{} `json:"data,omitempty" validate:"len=1"`
+	}
+
+	s2 := &ExternalCMD2{
+		Userid: "123456",
+		Action: 10000,
+		// Data:   1,
+	}
+
+	errs = validate.Struct(s2)
+	NotEqual(t, errs, nil)
+	Equal(t, errs.Errors["Data"].Field, "Data")
+	Equal(t, errs.Errors["Data"].Tag, "len")
+	Equal(t, errs.Errors["Data"].Param, "1")
+
+	s3 := &ExternalCMD2{
+		Userid: "123456",
+		Action: 10000,
+		Data:   2,
+	}
+
+	errs = validate.Struct(s3)
+	NotEqual(t, errs, nil)
+	Equal(t, errs.Errors["Data"].Field, "Data")
+	Equal(t, errs.Errors["Data"].Tag, "len")
+	Equal(t, errs.Errors["Data"].Param, "1")
+
+	type Inner struct {
+		Name string `validate:"required"`
+	}
+
+	inner := &Inner{
+		Name: "",
+	}
+
+	s4 := &ExternalCMD{
+		Userid: "123456",
+		Action: 10000,
+		Data:   inner,
+	}
+
+	errs = validate.Struct(s4)
+	NotEqual(t, errs, nil)
+	Equal(t, errs.StructErrors["Data"].Struct, "Inner")
+	Equal(t, errs.StructErrors["Data"].Errors["Name"].Field, "Name")
+	Equal(t, errs.StructErrors["Data"].Errors["Name"].Tag, "required")
+
+	type TestMapStructPtr struct {
+		Errs map[int]interface{} `validate:"gt=0,dive,len=2"`
+	}
+
+	mip := map[int]interface{}{0: &Inner{"ok"}, 3: nil, 4: &Inner{"ok"}}
+
+	msp := &TestMapStructPtr{
+		Errs: mip,
+	}
+
+	errs = validate.Struct(msp)
+	NotEqual(t, errs, nil)
+	Equal(t, len(errs.Errors), 1)
+
+	fieldError := errs.Errors["Errs"]
+	Equal(t, fieldError.IsPlaceholderErr, true)
+	Equal(t, fieldError.IsMap, true)
+	Equal(t, len(fieldError.MapErrs), 1)
+
+	innerFieldError, ok := fieldError.MapErrs[3].(*FieldError)
+	Equal(t, ok, true)
+	Equal(t, innerFieldError.IsPlaceholderErr, false)
+	Equal(t, innerFieldError.IsMap, false)
+	Equal(t, len(innerFieldError.MapErrs), 0)
+	Equal(t, innerFieldError.Field, "Errs[3]")
+	Equal(t, innerFieldError.Tag, "len")
+
+	type TestMultiDimensionalStructs struct {
+		Errs [][]interface{} `validate:"gt=0,dive,dive,len=2"`
+	}
+
+	var errStructArray [][]interface{}
+
+	errStructArray = append(errStructArray, []interface{}{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructArray = append(errStructArray, []interface{}{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+
+	tms := &TestMultiDimensionalStructs{
+		Errs: errStructArray,
+	}
+
+	errs = validate.Struct(tms)
+	NotEqual(t, errs, nil)
+	Equal(t, len(errs.Errors), 1)
+
+	fieldErr, ok := errs.Errors["Errs"]
+	Equal(t, ok, true)
+	Equal(t, fieldErr.IsPlaceholderErr, true)
+	Equal(t, fieldErr.IsSliceOrArray, true)
+	Equal(t, len(fieldErr.SliceOrArrayErrs), 2)
+
+	sliceError1, ok := fieldErr.SliceOrArrayErrs[0].(*FieldError)
+	Equal(t, ok, true)
+	Equal(t, sliceError1.IsPlaceholderErr, true)
+	Equal(t, sliceError1.IsSliceOrArray, true)
+	Equal(t, len(sliceError1.SliceOrArrayErrs), 2)
+
+	innerSliceStructError1, ok := sliceError1.SliceOrArrayErrs[1].(*StructErrors)
+	Equal(t, ok, true)
+	Equal(t, len(innerSliceStructError1.Errors), 1)
+
+	innerInnersliceError1 := innerSliceStructError1.Errors["Name"]
+	Equal(t, innerInnersliceError1.IsPlaceholderErr, false)
+	Equal(t, innerInnersliceError1.IsSliceOrArray, false)
+	Equal(t, len(innerInnersliceError1.SliceOrArrayErrs), 0)
+
+	type TestMultiDimensionalStructsPtr2 struct {
+		Errs [][]*Inner `validate:"gt=0,dive,dive,len=2"`
+	}
+
+	var errStructPtr2Array [][]*Inner
+
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, nil})
+
+	tmsp2 := &TestMultiDimensionalStructsPtr2{
+		Errs: errStructPtr2Array,
+	}
+
+	errs = validate.Struct(tmsp2)
+	NotEqual(t, errs, nil)
+	Equal(t, len(errs.Errors), 1)
+
+	fieldErr, ok = errs.Errors["Errs"]
+	Equal(t, ok, true)
+	Equal(t, fieldErr.IsPlaceholderErr, true)
+	Equal(t, fieldErr.IsSliceOrArray, true)
+	Equal(t, len(fieldErr.SliceOrArrayErrs), 3)
+
+	sliceError1, ok = fieldErr.SliceOrArrayErrs[2].(*FieldError)
+	Equal(t, ok, true)
+	Equal(t, sliceError1.IsPlaceholderErr, true)
+	Equal(t, sliceError1.IsSliceOrArray, true)
+	Equal(t, len(sliceError1.SliceOrArrayErrs), 2)
+
+	innerSliceStructError1, ok = sliceError1.SliceOrArrayErrs[1].(*StructErrors)
+	Equal(t, ok, true)
+	Equal(t, len(innerSliceStructError1.Errors), 1)
+
+	innerSliceStructError2, ok := sliceError1.SliceOrArrayErrs[2].(*FieldError)
+	Equal(t, ok, true)
+	Equal(t, innerSliceStructError2.IsPlaceholderErr, false)
+	Equal(t, innerSliceStructError2.IsSliceOrArray, false)
+	Equal(t, len(innerSliceStructError2.SliceOrArrayErrs), 0)
+	Equal(t, innerSliceStructError2.Field, "Errs[2][2]")
+
+	innerInnersliceError1 = innerSliceStructError1.Errors["Name"]
+	Equal(t, innerInnersliceError1.IsPlaceholderErr, false)
+	Equal(t, innerInnersliceError1.IsSliceOrArray, false)
+	Equal(t, len(innerInnersliceError1.SliceOrArrayErrs), 0)
+
+	m := map[int]interface{}{0: "ok", 3: "", 4: "ok"}
+
+	err = validate.Field(m, "len=3,dive,len=2")
+	NotEqual(t, err, nil)
+	Equal(t, err.IsPlaceholderErr, true)
+	Equal(t, err.IsMap, true)
+	Equal(t, len(err.MapErrs), 1)
+
+	err = validate.Field(m, "len=2,dive,required")
+	NotEqual(t, err, nil)
+	Equal(t, err.IsPlaceholderErr, false)
+	Equal(t, err.IsMap, false)
+	Equal(t, len(err.MapErrs), 0)
+
+	arr := []interface{}{"ok", "", "ok"}
+
+	err = validate.Field(arr, "len=3,dive,len=2")
+	NotEqual(t, err, nil)
+	Equal(t, err.IsPlaceholderErr, true)
+	Equal(t, err.IsSliceOrArray, true)
+	Equal(t, len(err.SliceOrArrayErrs), 1)
+
+	err = validate.Field(arr, "len=2,dive,required")
+	NotEqual(t, err, nil)
+	Equal(t, err.IsPlaceholderErr, false)
+	Equal(t, err.IsSliceOrArray, false)
+	Equal(t, len(err.SliceOrArrayErrs), 0)
+}
+
 func TestMapDiveValidation(t *testing.T) {
 
 	m := map[int]string{0: "ok", 3: "", 4: "ok"}