Update Validator Instance Check

README.md

@@ -225,9 +225,9 @@ How to Contribute
 There will always be a development branch for each version i.e. `v1-development`. In order to contribute, 
 please make your pull requests against those branches.
 
-If the changes being proposed or requested are breaking changes, please create an issue, for discussion 
-or create a pull request against the highest development branch for example this package has a 
-v1 and v1-development branch however, there will also be a v2-development brach even though v2 doesn't exist yet.
+If the changes being proposed or requested are breaking changes, please create an issue, for discussion
+or create a pull request against the highest development branch for example this package has a
+v1 and v1-development branch however, there will also be a v2-development branch even though v2 doesn't exist yet.
 
 I strongly encourage everyone whom creates a custom validation function to contribute them and
 help make this package even better.

validator.go

@@ -20,21 +20,22 @@ import (
 )
 
 const (
-	utf8HexComma        = "0x2C"
-	utf8Pipe            = "0x7C"
-	tagSeparator        = ","
-	orSeparator         = "|"
-	tagKeySeparator     = "="
-	structOnlyTag       = "structonly"
-	omitempty           = "omitempty"
-	skipValidationTag   = "-"
-	diveTag             = "dive"
-	existsTag           = "exists"
-	fieldErrMsg         = "Key: \"%s\" Error:Field validation for \"%s\" failed on the \"%s\" tag"
-	arrayIndexFieldName = "%s" + leftBracket + "%d" + rightBracket
-	mapIndexFieldName   = "%s" + leftBracket + "%v" + rightBracket
-	invalidValidation   = "Invalid validation tag on field %s"
-	undefinedValidation = "Undefined validation function on field %s"
+	utf8HexComma            = "0x2C"
+	utf8Pipe                = "0x7C"
+	tagSeparator            = ","
+	orSeparator             = "|"
+	tagKeySeparator         = "="
+	structOnlyTag           = "structonly"
+	omitempty               = "omitempty"
+	skipValidationTag       = "-"
+	diveTag                 = "dive"
+	existsTag               = "exists"
+	fieldErrMsg             = "Key: \"%s\" Error:Field validation for \"%s\" failed on the \"%s\" tag"
+	arrayIndexFieldName     = "%s" + leftBracket + "%d" + rightBracket
+	mapIndexFieldName       = "%s" + leftBracket + "%v" + rightBracket
+	invalidValidation       = "Invalid validation tag on field %s"
+	undefinedValidation     = "Undefined validation function on field %s"
+	validatorNotInitialized = "Validator instance not initialized"
 )
 
 var (
@@ -78,6 +79,12 @@ type Validate struct {
 	config Config
 }
 
+func (v *Validate) initCheck() {
+	if v == nil {
+		panic(validatorNotInitialized)
+	}
+}
+
 // Config contains the options that a Validator instance will use.
 // It is passed to the New() function
 type Config struct {
@@ -146,6 +153,7 @@ func New(config Config) *Validate {
 // NOTE: if the key already exists, the previous validation function will be replaced.
 // NOTE: this method is not thread-safe
 func (v *Validate) RegisterValidation(key string, f Func) error {
+	v.initCheck()
 
 	if len(key) == 0 {
 		return errors.New("Function Key cannot be empty")
@@ -162,6 +170,7 @@ func (v *Validate) RegisterValidation(key string, f Func) error {
 
 // RegisterCustomTypeFunc registers a CustomTypeFunc against a number of types
 func (v *Validate) RegisterCustomTypeFunc(fn CustomTypeFunc, types ...interface{}) {
+	v.initCheck()
 
 	if v.config.CustomTypeFuncs == nil {
 		v.config.CustomTypeFuncs = map[reflect.Type]CustomTypeFunc{}
@@ -178,6 +187,7 @@ func (v *Validate) RegisterCustomTypeFunc(fn CustomTypeFunc, types ...interface{
 // 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 {
+	v.initCheck()
 
 	errs := errsPool.Get().(ValidationErrors)
 	fieldVal := reflect.ValueOf(field)
@@ -196,6 +206,7 @@ func (v *Validate) Field(field interface{}, tag string) 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) FieldWithValue(val interface{}, field interface{}, tag string) ValidationErrors {
+	v.initCheck()
 
 	errs := errsPool.Get().(ValidationErrors)
 	topVal := reflect.ValueOf(val)
@@ -216,6 +227,7 @@ func (v *Validate) FieldWithValue(val interface{}, field interface{}, tag string
 // NOTE: This is normally not needed, however in some specific cases such as: tied to a
 // legacy data structure, it will be useful
 func (v *Validate) StructPartial(current interface{}, fields ...string) ValidationErrors {
+	v.initCheck()
 
 	sv, _ := v.extractType(reflect.ValueOf(current))
 	name := sv.Type().Name()
@@ -274,6 +286,7 @@ func (v *Validate) StructPartial(current interface{}, fields ...string) Validati
 // NOTE: This is normally not needed, however in some specific cases such as: tied to a
 // legacy data structure, it will be useful
 func (v *Validate) StructExcept(current interface{}, fields ...string) ValidationErrors {
+	v.initCheck()
 
 	sv, _ := v.extractType(reflect.ValueOf(current))
 	name := sv.Type().Name()
@@ -297,6 +310,7 @@ func (v *Validate) StructExcept(current interface{}, fields ...string) Validatio
 
 // Struct validates a structs exposed fields, and automatically validates nested structs, unless otherwise specified.
 func (v *Validate) Struct(current interface{}) ValidationErrors {
+	v.initCheck()
 
 	errs := errsPool.Get().(ValidationErrors)
 	sv := reflect.ValueOf(current)

validator_test.go

@@ -210,6 +210,31 @@ type TestPartial struct {
 	}
 }
 
+func TestNilValidator(t *testing.T) {
+
+	type TestStruct struct {
+		Test string `validate:"required"`
+	}
+
+	ts := TestStruct{}
+
+	var val *Validate
+
+	fn := func(v *Validate, topStruct reflect.Value, current reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
+
+		return current.String() == field.String()
+	}
+
+	PanicMatches(t, func() { val.RegisterCustomTypeFunc(ValidateCustomType, MadeUpCustomType{}) }, validatorNotInitialized)
+	PanicMatches(t, func() { val.RegisterValidation("something", fn) }, validatorNotInitialized)
+	PanicMatches(t, func() { val.Field(ts.Test, "required") }, validatorNotInitialized)
+	PanicMatches(t, func() { val.FieldWithValue("test", ts.Test, "required") }, validatorNotInitialized)
+	PanicMatches(t, func() { val.Struct(ts) }, validatorNotInitialized)
+	PanicMatches(t, func() { val.StructExcept(ts, "Test") }, validatorNotInitialized)
+	PanicMatches(t, func() { val.StructPartial(ts, "Test") }, validatorNotInitialized)
+
+}
+
 func TestStructPartial(t *testing.T) {
 
 	p1 := []string{