Merge pull request #153 from bluesuncorp/v6

Merge latest changes into v7-development

README.md

@@ -13,6 +13,7 @@ It has the following **unique** features:
 -   Cross Field and Cross Struct validations.  
 -   Slice, Array and Map diving, which allows any or all levels of a multidimensional field to be validated.  
 -   Handles type interface by determining it's underlying type prior to validation.
+-   Handles custom field types such as sql driver Valuer see [Valuer](https://golang.org/src/database/sql/driver/types.go?s=1210:1293#L29)
 
 Installation
 ------------
@@ -34,7 +35,9 @@ Usage and documentation
 
 Please see http://godoc.org/gopkg.in/bluesuncorp/validator.v6 for detailed usage docs.
 
-##### Example:
+##### Examples:
+
+Struct & Field validation
 ```go
 package main
 
@@ -73,6 +76,12 @@ func main() {
 
 	validate = validator.New(config)
 
+	validateStruct()
+	validateField()
+}
+
+func validateStruct() {
+
 	address := &Address{
 		Street: "Eavesdown Docks",
 		Planet: "Persphone",
@@ -109,6 +118,71 @@ func main() {
 
 	// save user to database
 }
+
+func validateField() {
+	myEmail := "joeybloggs.gmail.com"
+
+	errs := validate.Field(myEmail, "required,email")
+
+	if errs != nil {
+		fmt.Println(errs) // output: Key: "" Error:Field validation for "" failed on the "email" tag
+		return
+	}
+
+	// email ok, move on
+}
+```
+
+Custom Field Type
+```go
+package main
+
+import (
+	"database/sql"
+	"database/sql/driver"
+	"fmt"
+	"reflect"
+
+	"gopkg.in/bluesuncorp/validator.v6"
+)
+
+// DbBackedUser User struct
+type DbBackedUser struct {
+	Name sql.NullString `validate:"required"`
+	Age  sql.NullInt64  `validate:"required"`
+}
+
+func main() {
+
+	config := validator.Config{
+		TagName:         "validate",
+		ValidationFuncs: validator.BakedInValidators,
+	}
+
+	validate := validator.New(config)
+
+	// register all sql.Null* types to use the ValidateValuer CustomTypeFunc
+	validate.RegisterCustomTypeFunc(ValidateValuer, sql.NullString{}, sql.NullInt64{}, sql.NullBool{}, sql.NullFloat64{})
+
+	x := DbBackedUser{Name: sql.NullString{String: "", Valid: true}, Age: sql.NullInt64{Int64: 0, Valid: false}}
+	errs := validate.Struct(x)
+
+	if len(errs) > 0 {
+		fmt.Printf("Errs:\n%+v\n", errs)
+	}
+}
+
+// ValidateValuer implements validator.CustomTypeFunc
+func ValidateValuer(field reflect.Value) interface{} {
+	if valuer, ok := field.Interface().(driver.Valuer); ok {
+		val, err := valuer.Value()
+		if err == nil {
+			return val
+		}
+		// handle the error how you want
+	}
+	return nil
+}
 ```
 
 Benchmarks
@@ -120,12 +194,22 @@ hurt parallel performance too much.
 ```go
 $ go test -cpu=4 -bench=. -benchmem=true
 PASS
-BenchmarkField-4	 				 5000000	       314 ns/op	      16 B/op	       1 allocs/op
+BenchmarkFieldSuccess-4	 					 5000000	       318 ns/op	      16 B/op	       1 allocs/op
-BenchmarkFieldOrTag-4	  			  500000	      2425 ns/op	      20 B/op	       2 allocs/op
+BenchmarkFieldFailure-4	 					 5000000	       316 ns/op	      16 B/op	       1 allocs/op
-BenchmarkStructSimple-4	  			  500000	      3117 ns/op	     553 B/op	      14 allocs/op
+BenchmarkFieldCustomTypeSuccess-4	 		 3000000	       492 ns/op	      32 B/op	       2 allocs/op
-BenchmarkStructSimpleParallel-4	 	 1000000	      1149 ns/op	     553 B/op	      14 allocs/op
+BenchmarkFieldCustomTypeFailure-4	 		 2000000	       843 ns/op	     416 B/op	       6 allocs/op
-BenchmarkStructComplex-4	  		  100000	     19580 ns/op	    3230 B/op	     102 allocs/op
+BenchmarkFieldOrTagSuccess-4	  			  500000	      2384 ns/op	      20 B/op	       2 allocs/op
-BenchmarkStructComplexParallel-4	  200000	      6686 ns/op	    3232 B/op	     102 allocs/op
+BenchmarkFieldOrTagFailure-4	 			 1000000	      1295 ns/op	     384 B/op	       6 allocs/op
+BenchmarkStructSimpleSuccess-4	 			 1000000	      1175 ns/op	      24 B/op	       3 allocs/op
+BenchmarkStructSimpleFailure-4	 			 1000000	      1822 ns/op	     529 B/op	      11 allocs/op
+BenchmarkStructSimpleCustomTypeSuccess-4	 1000000	      1302 ns/op	      56 B/op	       5 allocs/op
+BenchmarkStructSimpleCustomTypeFailure-4	 1000000	      1847 ns/op	     577 B/op	      13 allocs/op
+BenchmarkStructSimpleSuccessParallel-4	 	 5000000	       339 ns/op	      24 B/op	       3 allocs/op
+BenchmarkStructSimpleFailureParallel-4	 	 2000000	       733 ns/op	     529 B/op	      11 allocs/op
+BenchmarkStructComplexSuccess-4	  			  200000	      7104 ns/op	     368 B/op	      30 allocs/op
+BenchmarkStructComplexFailure-4	  			  100000	     11996 ns/op	    2861 B/op	      72 allocs/op
+BenchmarkStructComplexSuccessParallel-4	 	 1000000	      2252 ns/op	     368 B/op	      30 allocs/op
+BenchmarkStructComplexFailureParallel-4	  	  300000	      4691 ns/op	    2862 B/op	      72 allocs/op
 ```
 
 How to Contribute

baked_in.go

@@ -2,6 +2,7 @@ package validator
 
 import (
 	"fmt"
+	"net"
 	"net/url"
 	"reflect"
 	"strconv"
@@ -64,6 +65,35 @@ var BakedInValidators = map[string]Func{
 	"latitude":     isLatitude,
 	"longitude":    isLongitude,
 	"ssn":          isSSN,
+	"ipv4":         isIPv4,
+	"ipv6":         isIPv6,
+	"ip":           isIP,
+	"mac":          isMac,
+}
+
+func isMac(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
+	_, err := net.ParseMAC(field.String())
+	return err == nil
+}
+
+func isIPv4(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
+
+	ip := net.ParseIP(field.String())
+
+	return ip != nil && ip.To4() != nil
+}
+
+func isIPv6(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
+	ip := net.ParseIP(field.String())
+
+	return ip != nil && ip.To4() == nil
+}
+
+func isIP(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
+
+	ip := net.ParseIP(field.String())
+
+	return ip != nil
 }
 
 func isSSN(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
@@ -403,10 +433,8 @@ 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()
 	}

benchmarks_test.go

@@ -1,20 +1,68 @@
 package validator
 
-import "testing"
+import (
+	sql "database/sql/driver"
+	"reflect"
+	"testing"
+)
 
-func BenchmarkField(b *testing.B) {
+func BenchmarkFieldSuccess(b *testing.B) {
 	for n := 0; n < b.N; n++ {
 		validate.Field("1", "len=1")
 	}
 }
 
-func BenchmarkFieldOrTag(b *testing.B) {
+func BenchmarkFieldFailure(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		validate.Field("2", "len=1")
+	}
+}
+
+func BenchmarkFieldCustomTypeSuccess(b *testing.B) {
+
+	customTypes := map[reflect.Type]CustomTypeFunc{}
+	customTypes[reflect.TypeOf((*sql.Valuer)(nil))] = ValidateValuerType
+	customTypes[reflect.TypeOf(valuer{})] = ValidateValuerType
+
+	validate := New(Config{TagName: "validate", ValidationFuncs: BakedInValidators, CustomTypeFuncs: customTypes})
+
+	val := valuer{
+		Name: "1",
+	}
+
+	for n := 0; n < b.N; n++ {
+		validate.Field(val, "len=1")
+	}
+}
+
+func BenchmarkFieldCustomTypeFailure(b *testing.B) {
+
+	customTypes := map[reflect.Type]CustomTypeFunc{}
+	customTypes[reflect.TypeOf((*sql.Valuer)(nil))] = ValidateValuerType
+	customTypes[reflect.TypeOf(valuer{})] = ValidateValuerType
+
+	validate := New(Config{TagName: "validate", ValidationFuncs: BakedInValidators, CustomTypeFuncs: customTypes})
+
+	val := valuer{}
+
+	for n := 0; n < b.N; n++ {
+		validate.Field(val, "len=1")
+	}
+}
+
+func BenchmarkFieldOrTagSuccess(b *testing.B) {
 	for n := 0; n < b.N; n++ {
 		validate.Field("rgba(0,0,0,1)", "rgb|rgba")
 	}
 }
 
-func BenchmarkStructSimple(b *testing.B) {
+func BenchmarkFieldOrTagFailure(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		validate.Field("#000", "rgb|rgba")
+	}
+}
+
+func BenchmarkStructSimpleSuccess(b *testing.B) {
 
 	type Foo struct {
 		StringValue string `validate:"min=5,max=10"`
@@ -22,15 +70,73 @@ func BenchmarkStructSimple(b *testing.B) {
 	}
 
 	validFoo := &Foo{StringValue: "Foobar", IntValue: 7}
-	invalidFoo := &Foo{StringValue: "Fo", IntValue: 3}
 
 	for n := 0; n < b.N; n++ {
 		validate.Struct(validFoo)
+	}
+}
+
+func BenchmarkStructSimpleFailure(b *testing.B) {
+
+	type Foo struct {
+		StringValue string `validate:"min=5,max=10"`
+		IntValue    int    `validate:"min=5,max=10"`
+	}
+
+	invalidFoo := &Foo{StringValue: "Fo", IntValue: 3}
+
+	for n := 0; n < b.N; n++ {
 		validate.Struct(invalidFoo)
 	}
 }
 
-func BenchmarkStructSimpleParallel(b *testing.B) {
+func BenchmarkStructSimpleCustomTypeSuccess(b *testing.B) {
+
+	customTypes := map[reflect.Type]CustomTypeFunc{}
+	customTypes[reflect.TypeOf((*sql.Valuer)(nil))] = ValidateValuerType
+	customTypes[reflect.TypeOf(valuer{})] = ValidateValuerType
+
+	validate := New(Config{TagName: "validate", ValidationFuncs: BakedInValidators, CustomTypeFuncs: customTypes})
+
+	val := valuer{
+		Name: "1",
+	}
+
+	type Foo struct {
+		Valuer   valuer `validate:"len=1"`
+		IntValue int    `validate:"min=5,max=10"`
+	}
+
+	validFoo := &Foo{Valuer: val, IntValue: 7}
+
+	for n := 0; n < b.N; n++ {
+		validate.Struct(validFoo)
+	}
+}
+
+func BenchmarkStructSimpleCustomTypeFailure(b *testing.B) {
+
+	customTypes := map[reflect.Type]CustomTypeFunc{}
+	customTypes[reflect.TypeOf((*sql.Valuer)(nil))] = ValidateValuerType
+	customTypes[reflect.TypeOf(valuer{})] = ValidateValuerType
+
+	validate := New(Config{TagName: "validate", ValidationFuncs: BakedInValidators, CustomTypeFuncs: customTypes})
+
+	val := valuer{}
+
+	type Foo struct {
+		Valuer   valuer `validate:"len=1"`
+		IntValue int    `validate:"min=5,max=10"`
+	}
+
+	validFoo := &Foo{Valuer: val, IntValue: 3}
+
+	for n := 0; n < b.N; n++ {
+		validate.Struct(validFoo)
+	}
+}
+
+func BenchmarkStructSimpleSuccessParallel(b *testing.B) {
 
 	type Foo struct {
 		StringValue string `validate:"min=5,max=10"`
@@ -38,41 +144,31 @@ func BenchmarkStructSimpleParallel(b *testing.B) {
 	}
 
 	validFoo := &Foo{StringValue: "Foobar", IntValue: 7}
-	invalidFoo := &Foo{StringValue: "Fo", IntValue: 3}
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
 			validate.Struct(validFoo)
-			validate.Struct(invalidFoo)
 		}
 	})
 }
 
-func BenchmarkStructComplex(b *testing.B) {
+func BenchmarkStructSimpleFailureParallel(b *testing.B) {
 
-	tFail := &TestString{
+	type Foo struct {
-		Required:  "",
+		StringValue string `validate:"min=5,max=10"`
-		Len:       "",
+		IntValue    int    `validate:"min=5,max=10"`
-		Min:       "",
+	}
-		Max:       "12345678901",
+
-		MinMax:    "",
+	invalidFoo := &Foo{StringValue: "Fo", IntValue: 3}
-		Lt:        "0123456789",
+
-		Lte:       "01234567890",
+	b.RunParallel(func(pb *testing.PB) {
-		Gt:        "1",
+		for pb.Next() {
-		Gte:       "1",
+			validate.Struct(invalidFoo)
-		OmitEmpty: "12345678901",
-		Sub: &SubTest{
-			Test: "",
-		},
-		Anonymous: struct {
-			A string `validate:"required"`
-		}{
-			A: "",
-		},
-		Iface: &Impl{
-			F: "12",
-		},
 		}
+	})
+}
+
+func BenchmarkStructComplexSuccess(b *testing.B) {
 
 	tSuccess := &TestString{
 		Required:  "Required",
@@ -103,11 +199,10 @@ func BenchmarkStructComplex(b *testing.B) {
 
 	for n := 0; n < b.N; n++ {
 		validate.Struct(tSuccess)
-		validate.Struct(tFail)
 	}
 }
 
-func BenchmarkStructComplexParallel(b *testing.B) {
+func BenchmarkStructComplexFailure(b *testing.B) {
 
 	tFail := &TestString{
 		Required:  "",
@@ -133,6 +228,13 @@ func BenchmarkStructComplexParallel(b *testing.B) {
 		},
 	}
 
+	for n := 0; n < b.N; n++ {
+		validate.Struct(tFail)
+	}
+}
+
+func BenchmarkStructComplexSuccessParallel(b *testing.B) {
+
 	tSuccess := &TestString{
 		Required:  "Required",
 		Len:       "length==10",
@@ -163,6 +265,38 @@ func BenchmarkStructComplexParallel(b *testing.B) {
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
 			validate.Struct(tSuccess)
+		}
+	})
+}
+
+func BenchmarkStructComplexFailureParallel(b *testing.B) {
+
+	tFail := &TestString{
+		Required:  "",
+		Len:       "",
+		Min:       "",
+		Max:       "12345678901",
+		MinMax:    "",
+		Lt:        "0123456789",
+		Lte:       "01234567890",
+		Gt:        "1",
+		Gte:       "1",
+		OmitEmpty: "12345678901",
+		Sub: &SubTest{
+			Test: "",
+		},
+		Anonymous: struct {
+			A string `validate:"required"`
+		}{
+			A: "",
+		},
+		Iface: &Impl{
+			F: "12",
+		},
+	}
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
 			validate.Struct(tFail)
 		}
 	})

doc.go

@@ -102,6 +102,14 @@ Here is a list of the current built in validators:
 		you know the struct will be valid, but need to verify it has been assigned.
 		NOTE: only "required" and "omitempty" can be used on a struct itself.
 
+	exists
+		Is a special tag without a validation function attached. It is used when a field
+		is a Pointer, Interface or Invalid and you wish to validate that it exists.
+		Example: want to ensure a bool exists if you define the bool as a pointer and
+		use exists it will ensure there is a value; couldn't use required as it would
+		fail when the bool was false. exists will fail is the value is a Pointer, Interface
+		or Invalid and is nil. (Usage: exists)
+
 	omitempty
 		Allows conditional validation, for example if a field is not set with
 		a value (Determined by the "required" validator) then other validation
@@ -121,16 +129,12 @@ Here is a list of the current built in validators:
 		gt=0 will be applied to []
 		[]string will be spared validation
 		required will be applied to string
-		NOTE: in Example2 if the required validation failed, but all others passed
-		the hierarchy of FieldError's in the middle with have their IsPlaceHolder field
-		set to true. If a FieldError has IsSliceOrMap=true or IsMap=true then the
-		FieldError is a Slice or Map field and if IsPlaceHolder=true then contains errors
-		within its SliceOrArrayErrs or MapErrs fields.
 
 	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
@@ -376,6 +380,24 @@ Here is a list of the current built in validators:
 		This validates that a string value contains a valid U.S. Social Security Number.
 		(Usage: ssn)
 
+	ip
+		This validates that a string value contains a valid IP Adress.
+		(Usage: ip)
+
+	ipv4
+		This validates that a string value contains a valid v4 IP Adress.
+		(Usage: ipv4)
+
+	ipv6
+		This validates that a string value contains a valid v6 IP Adress.
+		(Usage: ipv6)
+
+	mac
+		This validates that a string value contains a valid MAC Adress defined
+		by go's ParseMAC accepted formats and types see:
+		http://golang.org/src/net/mac.go?s=866:918#L29
+		(Usage: mac)
+
 Validator notes:
 
 	regex

examples/custom/custom.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"database/sql"
+	"database/sql/driver"
+	"fmt"
+	"reflect"
+
+	"gopkg.in/bluesuncorp/validator.v6"
+)
+
+// DbBackedUser User struct
+type DbBackedUser struct {
+	Name sql.NullString `validate:"required"`
+	Age  sql.NullInt64  `validate:"required"`
+}
+
+func main() {
+
+	config := validator.Config{
+		TagName:         "validate",
+		ValidationFuncs: validator.BakedInValidators,
+	}
+
+	validate := validator.New(config)
+
+	// register all sql.Null* types to use the ValidateValuer CustomTypeFunc
+	validate.RegisterCustomTypeFunc(ValidateValuer, sql.NullString{}, sql.NullInt64{}, sql.NullBool{}, sql.NullFloat64{})
+
+	x := DbBackedUser{Name: sql.NullString{String: "", Valid: true}, Age: sql.NullInt64{Int64: 0, Valid: false}}
+	errs := validate.Struct(x)
+
+	if len(errs) > 0 {
+		fmt.Printf("Errs:\n%+v\n", errs)
+	}
+}
+
+// ValidateValuer implements validator.CustomTypeFunc
+func ValidateValuer(field reflect.Value) interface{} {
+	if valuer, ok := field.Interface().(driver.Valuer); ok {
+		val, err := valuer.Value()
+		if err == nil {
+			return val
+		}
+		// handle the error how you want
+	}
+	return nil
+}

examples/simple/simple.go

@@ -1,7 +1,11 @@
 package main
 
 import (
+	"errors"
 	"fmt"
+	"reflect"
+
+	sql "database/sql/driver"
 
 	"gopkg.in/bluesuncorp/validator.v6"
 )
@@ -35,6 +39,12 @@ func main() {
 
 	validate = validator.New(config)
 
+	validateStruct()
+	validateField()
+}
+
+func validateStruct() {
+
 	address := &Address{
 		Street: "Eavesdown Docks",
 		Planet: "Persphone",
@@ -71,3 +81,85 @@ func main() {
 
 	// save user to database
 }
+
+func validateField() {
+	myEmail := "joeybloggs.gmail.com"
+
+	errs := validate.Field(myEmail, "required,email")
+
+	if errs != nil {
+		fmt.Println(errs) // output: Key: "" Error:Field validation for "" failed on the "email" tag
+		return
+	}
+
+	// email ok, move on
+}
+
+var validate2 *validator.Validate
+
+type valuer struct {
+	Name string
+}
+
+func (v valuer) Value() (sql.Value, error) {
+
+	if v.Name == "errorme" {
+		return nil, errors.New("some kind of error")
+	}
+
+	if v.Name == "blankme" {
+		return "", nil
+	}
+
+	if len(v.Name) == 0 {
+		return nil, nil
+	}
+
+	return v.Name, nil
+}
+
+// ValidateValuerType implements validator.CustomTypeFunc
+func ValidateValuerType(field reflect.Value) interface{} {
+	if valuer, ok := field.Interface().(sql.Valuer); ok {
+		val, err := valuer.Value()
+		if err != nil {
+			// handle the error how you want
+			return nil
+		}
+
+		return val
+	}
+
+	return nil
+}
+
+func main2() {
+
+	customTypes := map[reflect.Type]validator.CustomTypeFunc{}
+	customTypes[reflect.TypeOf((*sql.Valuer)(nil))] = ValidateValuerType
+	customTypes[reflect.TypeOf(valuer{})] = ValidateValuerType
+
+	config := validator.Config{
+		TagName:         "validate",
+		ValidationFuncs: validator.BakedInValidators,
+		CustomTypeFuncs: customTypes,
+	}
+
+	validate2 = validator.New(config)
+
+	validateCustomFieldType()
+}
+
+func validateCustomFieldType() {
+	val := valuer{
+		Name: "blankme",
+	}
+
+	errs := validate2.Field(val, "required")
+	if errs != nil {
+		fmt.Println(errs) // output: Key: "" Error:Field validation for "" failed on the "required" tag
+		return
+	}
+
+	// all ok
+}

validator.go

@@ -29,6 +29,7 @@ const (
 	omitempty           = "omitempty"
 	skipValidationTag   = "-"
 	diveTag             = "dive"
+	existsTag           = "exists"
 	fieldErrMsg         = "Key: \"%s\" Error:Field validation for \"%s\" failed on the \"%s\" tag"
 	arrayIndexFieldName = "%s[%d]"
 	mapIndexFieldName   = "%s[%v]"
@@ -45,7 +46,7 @@ var (
 
 // returns new ValidationErrors to the pool
 func newValidationErrors() interface{} {
-	return map[string]*FieldError{}
+	return ValidationErrors{}
 }
 
 type tagCache struct {
@@ -81,8 +82,15 @@ type Validate struct {
 type Config struct {
 	TagName         string
 	ValidationFuncs map[string]Func
+	CustomTypeFuncs map[reflect.Type]CustomTypeFunc
+	hasCustomFuncs  bool
 }
 
+// CustomTypeFunc allows for overriding or adding custom field type handler functions
+// field = field value of the type to return a value to be validated
+// example Valuer from sql drive see https://golang.org/src/database/sql/driver/types.go?s=1210:1293#L29
+type CustomTypeFunc func(field reflect.Value) interface{}
+
 // Func accepts all values needed for file and cross field validation
 // topStruct     = top level struct when validating by struct otherwise nil
 // currentStruct = current level struct when validating by struct otherwise optional comparison value
@@ -124,6 +132,11 @@ type FieldError struct {
 
 // New creates a new Validate instance for use.
 func New(config Config) *Validate {
+
+	if config.CustomTypeFuncs != nil && len(config.CustomTypeFuncs) > 0 {
+		config.hasCustomFuncs = true
+	}
+
 	return &Validate{config: config}
 }
 
@@ -145,12 +158,26 @@ func (v *Validate) RegisterValidation(key string, f Func) error {
 	return nil
 }
 
+// RegisterCustomTypeFunc registers a CustomTypeFunc against a number of types
+func (v *Validate) RegisterCustomTypeFunc(fn CustomTypeFunc, types ...interface{}) {
+
+	if v.config.CustomTypeFuncs == nil {
+		v.config.CustomTypeFuncs = map[reflect.Type]CustomTypeFunc{}
+	}
+
+	for _, t := range types {
+		v.config.CustomTypeFuncs[reflect.TypeOf(t)] = fn
+	}
+
+	v.config.hasCustomFuncs = true
+}
+
 // Field validates a single field using tag style validation and returns ValidationErrors
 // NOTE: it returns ValidationErrors instead of a single FieldError because this can also
 // validate Array, Slice and maps fields which may contain more than one error
 func (v *Validate) Field(field interface{}, tag string) ValidationErrors {
 
-	errs := errsPool.Get().(map[string]*FieldError)
+	errs := errsPool.Get().(ValidationErrors)
 	fieldVal := reflect.ValueOf(field)
 
 	v.traverseField(fieldVal, fieldVal, fieldVal, "", errs, false, tag, "")
@@ -168,7 +195,7 @@ func (v *Validate) Field(field interface{}, tag string) ValidationErrors {
 // validate Array, Slice and maps fields which may contain more than one error
 func (v *Validate) FieldWithValue(val interface{}, field interface{}, tag string) ValidationErrors {
 
-	errs := errsPool.Get().(map[string]*FieldError)
+	errs := errsPool.Get().(ValidationErrors)
 	topVal := reflect.ValueOf(val)
 
 	v.traverseField(topVal, topVal, reflect.ValueOf(field), "", errs, false, tag, "")
@@ -184,7 +211,7 @@ func (v *Validate) FieldWithValue(val interface{}, field interface{}, tag string
 // Struct validates a structs exposed fields, and automatically validates nested structs, unless otherwise specified.
 func (v *Validate) Struct(current interface{}) ValidationErrors {
 
-	errs := errsPool.Get().(map[string]*FieldError)
+	errs := errsPool.Get().(ValidationErrors)
 	sv := reflect.ValueOf(current)
 
 	v.tranverseStruct(sv, sv, sv, "", errs, true)
@@ -243,12 +270,10 @@ 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 +289,35 @@ 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:
 
@@ -302,6 +343,13 @@ func (v *Validate) traverseField(topStruct reflect.Value, currentStruct reflect.
 
 			if kind == reflect.Struct {
 
+				if v.config.hasCustomFuncs {
+					if fn, ok := v.config.CustomTypeFuncs[typ]; ok {
+						v.traverseField(topStruct, currentStruct, reflect.ValueOf(fn(current)), errPrefix, errs, isStructField, tag, name)
+						return
+					}
+				}
+
 				// required passed validation above so stop here
 				// if only validating the structs existance.
 				if strings.Contains(tag, structOnlyTag) {
@@ -320,6 +368,13 @@ func (v *Validate) traverseField(topStruct reflect.Value, currentStruct reflect.
 		}
 	}
 
+	if v.config.hasCustomFuncs {
+		if fn, ok := v.config.CustomTypeFuncs[typ]; ok {
+			v.traverseField(topStruct, currentStruct, reflect.ValueOf(fn(current)), errPrefix, errs, isStructField, tag, name)
+			return
+		}
+	}
+
 	tags, isCached := tagsCache.Get(tag)
 
 	if !isCached {
@@ -329,7 +384,7 @@ func (v *Validate) traverseField(topStruct reflect.Value, currentStruct reflect.
 		for _, t := range strings.Split(tag, tagSeparator) {
 
 			if t == diveTag {
-				tags = append(tags, &tagCache{tagVals: [][]string{[]string{t}}})
+				tags = append(tags, &tagCache{tagVals: [][]string{{t}}})
 				break
 			}
 
@@ -364,6 +419,10 @@ func (v *Validate) traverseField(topStruct reflect.Value, currentStruct reflect.
 
 	for _, cTag := range tags {
 
+		if cTag.tagVals[0][0] == existsTag {
+			continue
+		}
+
 		if cTag.tagVals[0][0] == diveTag {
 			dive = true
 			diveSubTag = strings.TrimLeft(strings.SplitN(tag, diveTag, 2)[1], ",")

validator_test.go

@@ -1,12 +1,15 @@
 package validator
 
 import (
+	"database/sql"
+	"database/sql/driver"
+	"encoding/json"
 	"fmt"
-	"path"
 	"reflect"
-	"runtime"
 	"testing"
 	"time"
+
+	. "gopkg.in/bluesuncorp/assert.v1"
 )
 
 // NOTES:
@@ -110,123 +113,449 @@ type TestSlice struct {
 
 var validate = New(Config{TagName: "validate", ValidationFuncs: BakedInValidators})
 
-func IsEqual(t *testing.T, val1, val2 interface{}) bool {
+func AssertError(t *testing.T, errs ValidationErrors, key, field, expectedTag string) {
-	v1 := reflect.ValueOf(val1)
-	v2 := reflect.ValueOf(val2)
 
-	if v1.Kind() == reflect.Ptr {
+	val, ok := errs[key]
-		v1 = v1.Elem()
+	EqualSkip(t, 2, ok, true)
+	NotEqualSkip(t, 2, val, nil)
+	EqualSkip(t, 2, val.Field, field)
+	EqualSkip(t, 2, val.Tag, expectedTag)
+}
+
+type valuer struct {
+	Name string
+}
+
+func (v valuer) Value() (driver.Value, error) {
+
+	if v.Name == "errorme" {
+		panic("SQL Driver Valuer error: some kind of error")
+		// return nil, errors.New("some kind of error")
 	}
 
-	if v2.Kind() == reflect.Ptr {
+	if len(v.Name) == 0 {
-		v2 = v2.Elem()
+		return nil, nil
 	}
 
-	if !v1.IsValid() && !v2.IsValid() {
+	return v.Name, nil
-		return true
+}
+
+type MadeUpCustomType struct {
+	FirstName string
+	LastName  string
+}
+
+func ValidateCustomType(field reflect.Value) interface{} {
+	if cust, ok := field.Interface().(MadeUpCustomType); ok {
+
+		if len(cust.FirstName) == 0 || len(cust.LastName) == 0 {
+			return ""
 		}
 
-	switch v1.Kind() {
+		return cust.FirstName + " " + cust.LastName
-	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
-		if v1.IsNil() {
-			v1 = reflect.ValueOf(nil)
 	}
+
+	return ""
+}
+
+func OverrideIntTypeForSomeReason(field reflect.Value) interface{} {
+
+	if i, ok := field.Interface().(int); ok {
+		if i == 1 {
+			return "1"
 		}
 
-	switch v2.Kind() {
+		if i == 2 {
-	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+			return "12"
-		if v2.IsNil() {
-			v2 = reflect.ValueOf(nil)
 		}
 	}
 
-	v1Underlying := reflect.Zero(reflect.TypeOf(v1)).Interface()
+	return ""
-	v2Underlying := reflect.Zero(reflect.TypeOf(v2)).Interface()
+}
 
-	if v1 == v1Underlying {
+type CustomMadeUpStruct struct {
-		if v2 == v2Underlying {
+	MadeUp        MadeUpCustomType `validate:"required"`
-			goto CASE4
+	OverriddenInt int              `validate:"gt=1"`
-		} else {
+}
-			goto CASE3
+
-		}
+func ValidateValuerType(field reflect.Value) interface{} {
-	} else {
+	if valuer, ok := field.Interface().(driver.Valuer); ok {
-		if v2 == v2Underlying {
+		val, err := valuer.Value()
-			goto CASE2
+		if err != nil {
-		} else {
+			// handle the error how you want
-			goto CASE1
+			return nil
 		}
+
+		return val
 	}
 
-CASE1:
+	return nil
-	// fmt.Println("CASE 1")
-	return reflect.DeepEqual(v1.Interface(), v2.Interface())
-CASE2:
-	// fmt.Println("CASE 2")
-	return reflect.DeepEqual(v1.Interface(), v2)
-CASE3:
-	// fmt.Println("CASE 3")
-	return reflect.DeepEqual(v1, v2.Interface())
-CASE4:
-	// fmt.Println("CASE 4")
-	return reflect.DeepEqual(v1, v2)
 }
 
-func Equal(t *testing.T, val1, val2 interface{}) {
+func TestExistsValidation(t *testing.T) {
-	EqualSkip(t, 2, val1, val2)
+
+	jsonText := "{ \"truthiness2\": true }"
+
+	type Thing struct {
+		Truthiness *bool `json:"truthiness" validate:"exists,required"`
+	}
+
+	var ting Thing
+
+	err := json.Unmarshal([]byte(jsonText), &ting)
+	Equal(t, err, nil)
+	NotEqual(t, ting, nil)
+	Equal(t, ting.Truthiness, nil)
+
+	errs := validate.Struct(ting)
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "Thing.Truthiness", "Truthiness", "exists")
+
+	jsonText = "{ \"truthiness\": true }"
+
+	err = json.Unmarshal([]byte(jsonText), &ting)
+	Equal(t, err, nil)
+	NotEqual(t, ting, nil)
+	Equal(t, ting.Truthiness, true)
+
+	errs = validate.Struct(ting)
+	Equal(t, errs, nil)
 }
 
-func EqualSkip(t *testing.T, skip int, val1, val2 interface{}) {
+func TestSQLValue2Validation(t *testing.T) {
+
+	config := Config{
+		TagName:         "validate",
+		ValidationFuncs: BakedInValidators,
+	}
+
+	validate := New(config)
+	validate.RegisterCustomTypeFunc(ValidateValuerType, valuer{}, (*driver.Valuer)(nil), sql.NullString{}, sql.NullInt64{}, sql.NullBool{}, sql.NullFloat64{})
+	validate.RegisterCustomTypeFunc(ValidateCustomType, MadeUpCustomType{})
+	validate.RegisterCustomTypeFunc(OverrideIntTypeForSomeReason, 1)
+
+	val := valuer{
+		Name: "",
+	}
 
-	if !IsEqual(t, val1, val2) {
+	errs := validate.Field(val, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
 
-		_, file, line, _ := runtime.Caller(skip)
+	val.Name = "Valid Name"
-		fmt.Printf("%s:%d %v does not equal %v\n", path.Base(file), line, val1, val2)
+	errs = validate.Field(val, "required")
-		t.FailNow()
+	Equal(t, errs, nil)
+
+	val.Name = "errorme"
+
+	PanicMatches(t, func() { validate.Field(val, "required") }, "SQL Driver Valuer error: some kind of error")
+
+	type myValuer valuer
+
+	myVal := valuer{
+		Name: "",
 	}
+
+	errs = validate.Field(myVal, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	cust := MadeUpCustomType{
+		FirstName: "Joey",
+		LastName:  "Bloggs",
+	}
+
+	c := CustomMadeUpStruct{MadeUp: cust, OverriddenInt: 2}
+
+	errs = validate.Struct(c)
+	Equal(t, errs, nil)
+
+	c.MadeUp.FirstName = ""
+	c.OverriddenInt = 1
+
+	errs = validate.Struct(c)
+	NotEqual(t, errs, nil)
+	Equal(t, len(errs), 2)
+	AssertError(t, errs, "CustomMadeUpStruct.MadeUp", "MadeUp", "required")
+	AssertError(t, errs, "CustomMadeUpStruct.OverriddenInt", "OverriddenInt", "gt")
 }
 
-func NotEqual(t *testing.T, val1, val2 interface{}) {
+func TestSQLValueValidation(t *testing.T) {
-	NotEqualSkip(t, 2, val1, val2)
+
+	customTypes := map[reflect.Type]CustomTypeFunc{}
+	customTypes[reflect.TypeOf((*driver.Valuer)(nil))] = ValidateValuerType
+	customTypes[reflect.TypeOf(valuer{})] = ValidateValuerType
+	customTypes[reflect.TypeOf(MadeUpCustomType{})] = ValidateCustomType
+	customTypes[reflect.TypeOf(1)] = OverrideIntTypeForSomeReason
+
+	validate := New(Config{TagName: "validate", ValidationFuncs: BakedInValidators, CustomTypeFuncs: customTypes})
+
+	val := valuer{
+		Name: "",
+	}
+
+	errs := validate.Field(val, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	val.Name = "Valid Name"
+	errs = validate.Field(val, "required")
+	Equal(t, errs, nil)
+
+	val.Name = "errorme"
+
+	PanicMatches(t, func() { errs = validate.Field(val, "required") }, "SQL Driver Valuer error: some kind of error")
+
+	type myValuer valuer
+
+	myVal := valuer{
+		Name: "",
+	}
+
+	errs = validate.Field(myVal, "required")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "required")
+
+	cust := MadeUpCustomType{
+		FirstName: "Joey",
+		LastName:  "Bloggs",
+	}
+
+	c := CustomMadeUpStruct{MadeUp: cust, OverriddenInt: 2}
+
+	errs = validate.Struct(c)
+	Equal(t, errs, nil)
+
+	c.MadeUp.FirstName = ""
+	c.OverriddenInt = 1
+
+	errs = validate.Struct(c)
+	NotEqual(t, errs, nil)
+	Equal(t, len(errs), 2)
+	AssertError(t, errs, "CustomMadeUpStruct.MadeUp", "MadeUp", "required")
+	AssertError(t, errs, "CustomMadeUpStruct.OverriddenInt", "OverriddenInt", "gt")
 }
 
-func NotEqualSkip(t *testing.T, skip int, val1, val2 interface{}) {
+func TestMACValidation(t *testing.T) {
+	tests := []struct {
+		param    string
+		expected bool
+	}{
+		{"3D:F2:C9:A6:B3:4F", true},
+		{"3D-F2-C9-A6-B3:4F", false},
+		{"123", false},
+		{"", false},
+		{"abacaba", false},
+		{"00:25:96:FF:FE:12:34:56", true},
+		{"0025:96FF:FE12:3456", false},
+	}
+
+	for i, test := range tests {
+
+		errs := validate.Field(test.param, "mac")
 
-	if IsEqual(t, val1, val2) {
+		if test.expected == true {
-		_, file, line, _ := runtime.Caller(skip)
+			if !IsEqual(errs, nil) {
-		fmt.Printf("%s:%d %v should not be equal %v\n", path.Base(file), line, val1, val2)
+				t.Fatalf("Index: %d mac failed Error: %s", i, errs)
-		t.FailNow()
+			}
+		} else {
+			if IsEqual(errs, nil) {
+				t.Fatalf("Index: %d mac failed Error: %s", i, errs)
+			} else {
+				val := errs[""]
+				if val.Tag != "mac" {
+					t.Fatalf("Index: %d mac failed Error: %s", i, errs)
+				}
+			}
+		}
 	}
 }
 
-func PanicMatches(t *testing.T, fn func(), matches string) {
+func TestIPValidation(t *testing.T) {
-	PanicMatchesSkip(t, 2, fn, matches)
+	tests := []struct {
+		param    string
+		expected bool
+	}{
+		{"10.0.0.1", true},
+		{"172.16.0.1", true},
+		{"192.168.0.1", true},
+		{"192.168.255.254", true},
+		{"192.168.255.256", false},
+		{"172.16.255.254", true},
+		{"172.16.256.255", false},
+		{"2001:cdba:0000:0000:0000:0000:3257:9652", true},
+		{"2001:cdba:0:0:0:0:3257:9652", true},
+		{"2001:cdba::3257:9652", true},
+	}
+
+	for i, test := range tests {
+
+		errs := validate.Field(test.param, "ip")
+
+		if test.expected == true {
+			if !IsEqual(errs, nil) {
+				t.Fatalf("Index: %d ip failed Error: %s", i, errs)
+			}
+		} else {
+			if IsEqual(errs, nil) {
+				t.Fatalf("Index: %d ip failed Error: %s", i, errs)
+			} else {
+				val := errs[""]
+				if val.Tag != "ip" {
+					t.Fatalf("Index: %d ip failed Error: %s", i, errs)
+				}
+			}
+		}
+	}
 }
 
-func PanicMatchesSkip(t *testing.T, skip int, fn func(), matches string) {
+func TestIPv6Validation(t *testing.T) {
+	tests := []struct {
+		param    string
+		expected bool
+	}{
+		{"10.0.0.1", false},
+		{"172.16.0.1", false},
+		{"192.168.0.1", false},
+		{"192.168.255.254", false},
+		{"192.168.255.256", false},
+		{"172.16.255.254", false},
+		{"172.16.256.255", false},
+		{"2001:cdba:0000:0000:0000:0000:3257:9652", true},
+		{"2001:cdba:0:0:0:0:3257:9652", true},
+		{"2001:cdba::3257:9652", true},
+	}
 
-	_, file, line, _ := runtime.Caller(skip)
+	for i, test := range tests {
 
-	defer func() {
+		errs := validate.Field(test.param, "ipv6")
-		if r := recover(); r != nil {
-			err := fmt.Sprintf("%s", r)
 
-			if err != matches {
+		if test.expected == true {
-				fmt.Printf("%s:%d Panic...  expected [%s] received [%s]", path.Base(file), line, matches, err)
+			if !IsEqual(errs, nil) {
-				t.FailNow()
+				t.Fatalf("Index: %d ipv6 failed Error: %s", i, errs)
+			}
+		} else {
+			if IsEqual(errs, nil) {
+				t.Fatalf("Index: %d ipv6 failed Error: %s", i, errs)
+			} else {
+				val := errs[""]
+				if val.Tag != "ipv6" {
+					t.Fatalf("Index: %d ipv6 failed Error: %s", i, errs)
 				}
 			}
-	}()
+		}
+	}
+}
 
-	fn()
+func TestIPv4Validation(t *testing.T) {
+	tests := []struct {
+		param    string
+		expected bool
+	}{
+		{"10.0.0.1", true},
+		{"172.16.0.1", true},
+		{"192.168.0.1", true},
+		{"192.168.255.254", true},
+		{"192.168.255.256", false},
+		{"172.16.255.254", true},
+		{"172.16.256.255", false},
+		{"2001:cdba:0000:0000:0000:0000:3257:9652", false},
+		{"2001:cdba:0:0:0:0:3257:9652", false},
+		{"2001:cdba::3257:9652", false},
+	}
+
+	for i, test := range tests {
+
+		errs := validate.Field(test.param, "ipv4")
+
+		if test.expected == true {
+			if !IsEqual(errs, nil) {
+				t.Fatalf("Index: %d ipv4 failed Error: %s", i, errs)
+			}
+		} else {
+			if IsEqual(errs, nil) {
+				t.Fatalf("Index: %d ipv4 failed Error: %s", i, errs)
+			} else {
+				val := errs[""]
+				if val.Tag != "ipv4" {
+					t.Fatalf("Index: %d ipv4 failed Error: %s", i, errs)
+				}
+			}
+		}
+	}
 }
 
-func AssertError(t *testing.T, errs ValidationErrors, key, field, expectedTag string) {
+func TestSliceMapArrayChanFuncPtrInterfaceRequiredValidation(t *testing.T) {
 
-	val, ok := errs[key]
+	var m map[string]string
-	EqualSkip(t, 2, ok, true)
+
-	NotEqualSkip(t, 2, val, nil)
+	errs := validate.Field(m, "required")
-	EqualSkip(t, 2, val.Field, field)
+	NotEqual(t, errs, nil)
-	EqualSkip(t, 2, val.Tag, expectedTag)
+	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) {
@@ -396,9 +725,9 @@ func TestInterfaceErrValidation(t *testing.T) {
 
 	var errStructPtr2Array [][]*Inner
 
-	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, nil})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{{"ok"}, {""}, nil})
 
 	tmsp2 := &TestMultiDimensionalStructsPtr2{
 		Errs: errStructPtr2Array,
@@ -478,7 +807,7 @@ func TestMapDiveValidation(t *testing.T) {
 		Errs map[int]Inner `validate:"gt=0,dive"`
 	}
 
-	mi := map[int]Inner{0: Inner{"ok"}, 3: Inner{""}, 4: Inner{"ok"}}
+	mi := map[int]Inner{0: {"ok"}, 3: {""}, 4: {"ok"}}
 
 	ms := &TestMapStruct{
 		Errs: mi,
@@ -514,7 +843,7 @@ func TestMapDiveValidation(t *testing.T) {
 		Errs map[int]*Inner `validate:"gt=0,dive,required"`
 	}
 
-	mip := map[int]*Inner{0: &Inner{"ok"}, 3: nil, 4: &Inner{"ok"}}
+	mip := map[int]*Inner{0: {"ok"}, 3: nil, 4: {"ok"}}
 
 	msp := &TestMapStructPtr{
 		Errs: mip,
@@ -529,7 +858,7 @@ func TestMapDiveValidation(t *testing.T) {
 		Errs map[int]*Inner `validate:"gt=0,dive,omitempty,required"`
 	}
 
-	mip2 := map[int]*Inner{0: &Inner{"ok"}, 3: nil, 4: &Inner{"ok"}}
+	mip2 := map[int]*Inner{0: {"ok"}, 3: nil, 4: {"ok"}}
 
 	msp2 := &TestMapStructPtr2{
 		Errs: mip2,
@@ -616,8 +945,8 @@ func TestArrayDiveValidation(t *testing.T) {
 
 	var errStructArray [][]Inner
 
-	errStructArray = append(errStructArray, []Inner{Inner{"ok"}, Inner{""}, Inner{""}})
+	errStructArray = append(errStructArray, []Inner{{"ok"}, {""}, {""}})
-	errStructArray = append(errStructArray, []Inner{Inner{"ok"}, Inner{""}, Inner{""}})
+	errStructArray = append(errStructArray, []Inner{{"ok"}, {""}, {""}})
 
 	tms := &TestMultiDimensionalStructs{
 		Errs: errStructArray,
@@ -637,9 +966,9 @@ func TestArrayDiveValidation(t *testing.T) {
 
 	var errStructPtrArray [][]*Inner
 
-	errStructPtrArray = append(errStructPtrArray, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtrArray = append(errStructPtrArray, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtrArray = append(errStructPtrArray, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtrArray = append(errStructPtrArray, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtrArray = append(errStructPtrArray, []*Inner{&Inner{"ok"}, &Inner{""}, nil})
+	errStructPtrArray = append(errStructPtrArray, []*Inner{{"ok"}, {""}, nil})
 
 	tmsp := &TestMultiDimensionalStructsPtr{
 		Errs: errStructPtrArray,
@@ -662,9 +991,9 @@ func TestArrayDiveValidation(t *testing.T) {
 
 	var errStructPtr2Array [][]*Inner
 
-	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtr2Array = append(errStructPtr2Array, []*Inner{&Inner{"ok"}, &Inner{""}, nil})
+	errStructPtr2Array = append(errStructPtr2Array, []*Inner{{"ok"}, {""}, nil})
 
 	tmsp2 := &TestMultiDimensionalStructsPtr2{
 		Errs: errStructPtr2Array,
@@ -686,9 +1015,9 @@ func TestArrayDiveValidation(t *testing.T) {
 
 	var errStructPtr3Array [][]*Inner
 
-	errStructPtr3Array = append(errStructPtr3Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr3Array = append(errStructPtr3Array, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtr3Array = append(errStructPtr3Array, []*Inner{&Inner{"ok"}, &Inner{""}, &Inner{""}})
+	errStructPtr3Array = append(errStructPtr3Array, []*Inner{{"ok"}, {""}, {""}})
-	errStructPtr3Array = append(errStructPtr3Array, []*Inner{&Inner{"ok"}, &Inner{""}, nil})
+	errStructPtr3Array = append(errStructPtr3Array, []*Inner{{"ok"}, {""}, nil})
 
 	tmsp3 := &TestMultiDimensionalStructsPtr3{
 		Errs: errStructPtr3Array,
@@ -864,11 +1193,11 @@ func TestSSNValidation(t *testing.T) {
 		errs := validate.Field(test.param, "ssn")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d SSN failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d SSN failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -898,11 +1227,11 @@ func TestLongitudeValidation(t *testing.T) {
 		errs := validate.Field(test.param, "longitude")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Longitude failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Longitude failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -932,11 +1261,11 @@ func TestLatitudeValidation(t *testing.T) {
 		errs := validate.Field(test.param, "latitude")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Latitude failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Latitude failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -972,11 +1301,11 @@ func TestDataURIValidation(t *testing.T) {
 		errs := validate.Field(test.param, "datauri")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d DataURI failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d DataURI failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1010,11 +1339,11 @@ func TestMultibyteValidation(t *testing.T) {
 		errs := validate.Field(test.param, "multibyte")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Multibyte failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Multibyte failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1049,11 +1378,11 @@ func TestPrintableASCIIValidation(t *testing.T) {
 		errs := validate.Field(test.param, "printascii")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Printable ASCII failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d Printable ASCII failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1087,11 +1416,11 @@ func TestASCIIValidation(t *testing.T) {
 		errs := validate.Field(test.param, "ascii")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ASCII failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ASCII failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1122,11 +1451,11 @@ func TestUUID5Validation(t *testing.T) {
 		errs := validate.Field(test.param, "uuid5")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID5 failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID5 failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1156,11 +1485,11 @@ func TestUUID4Validation(t *testing.T) {
 		errs := validate.Field(test.param, "uuid4")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID4 failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID4 failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1189,11 +1518,11 @@ func TestUUID3Validation(t *testing.T) {
 		errs := validate.Field(test.param, "uuid3")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID3 failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID3 failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1225,11 +1554,11 @@ func TestUUIDValidation(t *testing.T) {
 		errs := validate.Field(test.param, "uuid")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d UUID failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1263,11 +1592,11 @@ func TestISBNValidation(t *testing.T) {
 		errs := validate.Field(test.param, "isbn")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ISBN failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ISBN failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1300,11 +1629,11 @@ func TestISBN13Validation(t *testing.T) {
 		errs := validate.Field(test.param, "isbn13")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ISBN13 failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ISBN13 failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -1338,11 +1667,11 @@ func TestISBN10Validation(t *testing.T) {
 		errs := validate.Field(test.param, "isbn10")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ISBN10 failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d ISBN10 failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -2702,11 +3031,11 @@ func TestUrl(t *testing.T) {
 		errs := validate.Field(test.param, "url")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d URL failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d URL failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -2766,11 +3095,11 @@ func TestUri(t *testing.T) {
 		errs := validate.Field(test.param, "uri")
 
 		if test.expected == true {
-			if !IsEqual(t, errs, nil) {
+			if !IsEqual(errs, nil) {
 				t.Fatalf("Index: %d URI failed Error: %s", i, errs)
 			}
 		} else {
-			if IsEqual(t, errs, nil) {
+			if IsEqual(errs, nil) {
 				t.Fatalf("Index: %d URI failed Error: %s", i, errs)
 			} else {
 				val := errs[""]
@@ -2858,7 +3187,9 @@ func TestHsla(t *testing.T) {
 	AssertError(t, errs, "", "", "hsla")
 
 	i := 1
-	PanicMatches(t, func() { validate.Field(i, "hsla") }, "interface conversion: interface is int, not string")
+	validate.Field(i, "hsla")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "hsla")
 }
 
 func TestHsl(t *testing.T) {
@@ -2892,7 +3223,9 @@ func TestHsl(t *testing.T) {
 	AssertError(t, errs, "", "", "hsl")
 
 	i := 1
-	PanicMatches(t, func() { validate.Field(i, "hsl") }, "interface conversion: interface is int, not string")
+	errs = validate.Field(i, "hsl")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "hsl")
 }
 
 func TestRgba(t *testing.T) {
@@ -2934,7 +3267,9 @@ func TestRgba(t *testing.T) {
 	AssertError(t, errs, "", "", "rgba")
 
 	i := 1
-	PanicMatches(t, func() { validate.Field(i, "rgba") }, "interface conversion: interface is int, not string")
+	errs = validate.Field(i, "rgba")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "rgba")
 }
 
 func TestRgb(t *testing.T) {
@@ -2972,7 +3307,9 @@ func TestRgb(t *testing.T) {
 	AssertError(t, errs, "", "", "rgb")
 
 	i := 1
-	PanicMatches(t, func() { validate.Field(i, "rgb") }, "interface conversion: interface is int, not string")
+	errs = validate.Field(i, "rgb")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "rgb")
 }
 
 func TestEmail(t *testing.T) {
@@ -3002,7 +3339,9 @@ func TestEmail(t *testing.T) {
 	AssertError(t, errs, "", "", "email")
 
 	i := true
-	PanicMatches(t, func() { validate.Field(i, "email") }, "interface conversion: interface is bool, not string")
+	errs = validate.Field(i, "email")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "email")
 }
 
 func TestHexColor(t *testing.T) {
@@ -3026,7 +3365,9 @@ func TestHexColor(t *testing.T) {
 	AssertError(t, errs, "", "", "hexcolor")
 
 	i := true
-	PanicMatches(t, func() { validate.Field(i, "hexcolor") }, "interface conversion: interface is bool, not string")
+	errs = validate.Field(i, "hexcolor")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "hexcolor")
 }
 
 func TestHexadecimal(t *testing.T) {
@@ -3041,7 +3382,9 @@ func TestHexadecimal(t *testing.T) {
 	AssertError(t, errs, "", "", "hexadecimal")
 
 	i := true
-	PanicMatches(t, func() { validate.Field(i, "hexadecimal") }, "interface conversion: interface is bool, not string")
+	errs = validate.Field(i, "hexadecimal")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "hexadecimal")
 }
 
 func TestNumber(t *testing.T) {
@@ -3086,7 +3429,9 @@ func TestNumber(t *testing.T) {
 	AssertError(t, errs, "", "", "number")
 
 	i := 1
-	PanicMatches(t, func() { validate.Field(i, "number") }, "interface conversion: interface is int, not string")
+	errs = validate.Field(i, "number")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "number")
 }
 
 func TestNumeric(t *testing.T) {
@@ -3126,7 +3471,9 @@ func TestNumeric(t *testing.T) {
 	AssertError(t, errs, "", "", "numeric")
 
 	i := 1
-	PanicMatches(t, func() { validate.Field(i, "numeric") }, "interface conversion: interface is int, not string")
+	errs = validate.Field(i, "numeric")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "numeric")
 }
 
 func TestAlphaNumeric(t *testing.T) {
@@ -3140,7 +3487,9 @@ func TestAlphaNumeric(t *testing.T) {
 	NotEqual(t, errs, nil)
 	AssertError(t, errs, "", "", "alphanum")
 
-	PanicMatches(t, func() { validate.Field(1, "alphanum") }, "interface conversion: interface is int, not string")
+	errs = validate.Field(1, "alphanum")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "alphanum")
 }
 
 func TestAlpha(t *testing.T) {
@@ -3152,10 +3501,11 @@ func TestAlpha(t *testing.T) {
 	s = "abc1"
 	errs = validate.Field(s, "alpha")
 	NotEqual(t, errs, nil)
-
 	AssertError(t, errs, "", "", "alpha")
 
-	PanicMatches(t, func() { validate.Field(1, "alpha") }, "interface conversion: interface is int, not string")
+	errs = validate.Field(1, "alpha")
+	NotEqual(t, errs, nil)
+	AssertError(t, errs, "", "", "alpha")
 }
 
 func TestStructStringValidation(t *testing.T) {
@@ -3372,14 +3722,14 @@ 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},
@@ -3408,22 +3758,6 @@ func TestInvalidStruct(t *testing.T) {
 	PanicMatches(t, func() { validate.Struct(s.Test) }, "value passed for validation is not a struct")
 }
 
-func TestInvalidField(t *testing.T) {
-	s := &SubTest{
-		Test: "1",
-	}
-
-	PanicMatches(t, func() { validate.Field(s, "required") }, "Invalid field passed to traverseField")
-}
-
-func TestInvalidTagField(t *testing.T) {
-	s := &SubTest{
-		Test: "1",
-	}
-
-	PanicMatches(t, func() { validate.Field(s.Test, "") }, fmt.Sprintf("Invalid validation tag on field %s", ""))
-}
-
 func TestInvalidValidatorFunction(t *testing.T) {
 	s := &SubTest{
 		Test: "1",