better error message.

cache.go

@@ -21,8 +21,8 @@ const (
 )
 
 const (
-	invalidValidation   = "Invalid validation tag on field %s"
+	invalidValidation   = "Invalid validation tag on field '%s'"
-	undefinedValidation = "Undefined validation function on field %s"
+	undefinedValidation = "Undefined validation function '%s' on field '%s'"
 )
 
 // var (
@@ -267,7 +267,7 @@ func (v *Validate) parseFieldTagsRecursive(tag string, fieldName string, alias s
 				}
 
 				if current.fn, ok = v.validations[current.tag]; !ok {
-					panic(strings.TrimSpace(fmt.Sprintf(undefinedValidation, fieldName)))
+					panic(strings.TrimSpace(fmt.Sprintf(undefinedValidation, current.tag, fieldName)))
 				}
 
 				if len(orVals) > 1 {

validator_test.go

@@ -2625,7 +2625,7 @@ func TestBadKeyValidation(t *testing.T) {
 
 	validate := New()
 
-	PanicMatches(t, func() { validate.Struct(tst) }, "Undefined validation function on field Name")
+	PanicMatches(t, func() { validate.Struct(tst) }, "Undefined validation function ' ' on field 'Name'")
 
 	type Test2 struct {
 		Name string `validate:"required,,len=2"`
@@ -2635,7 +2635,7 @@ func TestBadKeyValidation(t *testing.T) {
 		Name: "test",
 	}
 
-	PanicMatches(t, func() { validate.Struct(tst2) }, "Invalid validation tag on field Name")
+	PanicMatches(t, func() { validate.Struct(tst2) }, "Invalid validation tag on field 'Name'")
 }
 
 func TestInterfaceErrValidation(t *testing.T) {
@@ -5413,8 +5413,8 @@ func TestOrTag(t *testing.T) {
 
 	s = "this is right, but a blank or isn't"
 
-	PanicMatches(t, func() { validate.Var(s, "rgb||len=13") }, "Invalid validation tag on field")
+	PanicMatches(t, func() { validate.Var(s, "rgb||len=13") }, "Invalid validation tag on field ''")
-	PanicMatches(t, func() { validate.Var(s, "rgb|rgbaa|len=13") }, "Undefined validation function on field")
+	PanicMatches(t, func() { validate.Var(s, "rgb|rgbaa|len=13") }, "Undefined validation function 'rgbaa' on field ''")
 }
 
 func TestHsla(t *testing.T) {
@@ -6116,7 +6116,7 @@ func TestInvalidValidatorFunction(t *testing.T) {
 		Test: "1",
 	}
 
-	PanicMatches(t, func() { validate.Var(s.Test, "zzxxBadFunction") }, "Undefined validation function on field")
+	PanicMatches(t, func() { validate.Var(s.Test, "zzxxBadFunction") }, "Undefined validation function 'zzxxBadFunction' on field ''")
 }
 
 func TestCustomFieldName(t *testing.T) {