Add .Validate() to ytypes.Schema and ygot.ValidateGoStruct() (#732)

* Add .Validate() to ytypes.Schema

* Add ygot.ValidateGoStruct

ygot/struct_validation_map.go

@@ -411,18 +411,13 @@ func EmitJSON(gs GoStruct, opts *EmitJSONConfig) (string, error) {
 		skipValidation = opts.SkipValidation
 	}
 
-	s, ok := gs.(validatedGoStruct)
-	if !ok {
-		return "", fmt.Errorf("input GoStruct does not have ΛValidate() method")
-	}
-
 	if !skipValidation {
-		if err := s.ΛValidate(vopts...); err != nil {
+		if err := ValidateGoStruct(gs, vopts...); err != nil {
 			return "", fmt.Errorf("validation err: %v", err)
 		}
 	}
 
-	v, err := makeJSON(s, opts)
+	v, err := makeJSON(gs, opts)
 	if err != nil {
 		return "", err
 	}

ygot/types.go

@@ -15,6 +15,7 @@
 package ygot
 
 import (
+	"fmt"
 	"reflect"
 )
 
@@ -56,6 +57,15 @@ type ValidatedGoStruct interface {
 	ΛBelongingModule() string
 }
 
+// ValidateGoStruct validates a GoStruct.
+func ValidateGoStruct(goStruct GoStruct, vopts ...ValidationOption) error {
+	vroot, ok := goStruct.(validatedGoStruct)
+	if !ok {
+		return fmt.Errorf("GoStruct cannot be validated: (%T, %v)", goStruct, goStruct)
+	}
+	return vroot.ΛValidate(vopts...)
+}
+
 // validatedGoStruct is an interface used for validating GoStructs.
 // This interface is implemented by all Go structs (YANG container or lists),
 // regardless of generation flag.

ytypes/types.go

@@ -15,6 +15,7 @@
 package ytypes
 
 import (
+	"errors"
 	"reflect"
 
 	"github.com/openconfig/goyang/pkg/yang"
@@ -41,5 +42,13 @@ func (s *Schema) RootSchema() *yang.Entry {
 	return s.SchemaTree[reflect.TypeOf(s.Root).Elem().Name()]
 }
 
+// Validate performs schema validation on the schema root.
+func (s *Schema) Validate(vopts ...ygot.ValidationOption) error {
+	if !s.IsValid() {
+		return errors.New("invalid schema: not fully populated")
+	}
+	return ygot.ValidateGoStruct(s.Root, vopts...)
+}
+
 // UnmarshalFunc defines a common signature for an RFC7951 to ygot.GoStruct unmarshalling function
 type UnmarshalFunc func([]byte, ygot.GoStruct, ...UnmarshalOpt) error

ytypes/types_test.go

@@ -68,6 +68,10 @@ func TestSchema(t *testing.T) {
 				t.Errorf("did not get expected valid status, got: %v, want: %v", got, tt.wantValid)
 			}
 
+			if got := tt.in.Validate(); (got == nil) != tt.wantValid {
+				t.Errorf("did not get expected validate return, got: %v, want: %v", got, tt.wantValid)
+			}
+
 			if !tt.wantValid {
 				return
 			}