Enable customValidation on root (#438)

* Enable customValidation on root

* handle review comments

* remove CustomValidFuncType

Co-authored-by: samanta <soumik.samanta@nokia.com>

ytypes/validate.go

@@ -43,6 +43,17 @@ type LeafrefOptions struct {
 // interface.
 func (*LeafrefOptions) IsValidationOption() {}
 
+// CustomValidationOptions controls the custom validate function to be
+// invoked on the root
+type CustomValidationOptions struct {
+	// FakeRootCustomValidate specifies the user implemented method
+	FakeRootCustomValidate func(ygot.GoStruct) error
+}
+
+// IsValidationOption ensures that CustomValidationOptions implements the ValidationOption
+// interface.
+func (*CustomValidationOptions) IsValidationOption() {}
+
 // Validate recursively validates the value of the given data tree struct
 // against the given schema.
 func Validate(schema *yang.Entry, value interface{}, opts ...ygot.ValidationOption) util.Errors {
@@ -60,10 +71,13 @@ func Validate(schema *yang.Entry, value interface{}, opts ...ygot.ValidationOpti
 	// and overwrite with the last within the options slice, rather than
 	// explicitly returning an error.
 	var leafrefOpt *LeafrefOptions
+	var customValidOpt *CustomValidationOptions
 	for _, o := range opts {
 		switch v := o.(type) {
 		case *LeafrefOptions:
 			leafrefOpt = v
+		case *CustomValidationOptions:
+			customValidOpt = v
 		}
 	}
 
@@ -72,6 +86,14 @@ func Validate(schema *yang.Entry, value interface{}, opts ...ygot.ValidationOpti
 		// Leafref validation traverses entire tree from the root. Do this only
 		// once from the fakeroot.
 		errs = ValidateLeafRefData(schema, value, leafrefOpt)
+		// If CustomValidation is enabled, call the CustomValidateFunc
+		// and append the error, if any
+		gsv, ok := value.(ygot.GoStruct)
+		if ok && customValidOpt != nil {
+			if err := customValidOpt.FakeRootCustomValidate(gsv); err != nil {
+				errs = util.AppendErr(errs, err)
+			}
+		}
 	}
 
 	util.DbgPrint("Validate with value %v, type %T, schema name %s", util.ValueStr(value), value, schema.Name)
@@ -92,6 +114,5 @@ func Validate(schema *yang.Entry, value interface{}, opts ...ygot.ValidationOpti
 	case schema.IsChoice():
 		return util.AppendErrs(errs, util.NewErrs(fmt.Errorf("cannot pass choice schema %s to Validate", schema.Name)))
 	}
-
 	return util.AppendErrs(errs, util.NewErrs(fmt.Errorf("unknown schema type for type %T, value %v", value, value)))
 }

ytypes/validate_test.go

@@ -15,6 +15,7 @@
 package ytypes
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/openconfig/goyang/pkg/yang"
@@ -46,6 +47,16 @@ type FakeRootStruct struct {
 
 func (*FakeRootStruct) IsYANGGoStruct() {}
 
+func customValidation(val ygot.GoStruct) error {
+	fakeRoot, ok := val.(*FakeRootStruct)
+	if !ok {
+		return fmt.Errorf("not valid fakeroot")
+	}
+	if fakeRoot.LeafThree == nil || *fakeRoot.LeafThree != "kingfisher" {
+		return fmt.Errorf("leafThree should be kingfisher")
+	}
+	return nil
+}
 func TestValidate(t *testing.T) {
 	leafSchema := &yang.Entry{Name: "leaf-schema", Kind: yang.LeafEntry, Type: &yang.YangType{Kind: yang.Ystring}}
 
@@ -189,6 +200,37 @@ func TestValidate(t *testing.T) {
 			},
 			opts: []ygot.ValidationOption{&LeafrefOptions{IgnoreMissingData: true}},
 		},
+		{
+			desc:   "fakeroot with custom validation",
+			schema: fakerootSchema,
+			val: &FakeRootStruct{
+				LeafOne: ygot.String("one"),
+				LeafTwo: ygot.String("one"),
+			},
+			opts:       []ygot.ValidationOption{&CustomValidationOptions{FakeRootCustomValidate: customValidation}},
+			wantErr:    "leafThree should be kingfisher",
+			wantErrLen: 1,
+		},
+		{
+			desc:   "fakeroot with custom validation and ignore bad leafref",
+			schema: fakerootSchema,
+			val: &FakeRootStruct{
+				LeafTwo: ygot.String("two"),
+			},
+			opts:       []ygot.ValidationOption{&LeafrefOptions{IgnoreMissingData: true}, &CustomValidationOptions{FakeRootCustomValidate: customValidation}},
+			wantErr:    "leafThree should be kingfisher",
+			wantErrLen: 1,
+		},
+		{
+			desc:   "fakeroot with custom validation and bad leafref",
+			schema: fakerootSchema,
+			val: &FakeRootStruct{
+				LeafTwo: ygot.String("two"),
+			},
+			opts:       []ygot.ValidationOption{&CustomValidationOptions{FakeRootCustomValidate: customValidation}},
+			wantErr:    "pointed-to value with path ../leaf-one from field LeafTwo value two (string ptr) schema /device/leaf-two is empty set, leafThree should be kingfisher",
+			wantErrLen: 2,
+		},
 		{
 			desc:   "two errors",
 			schema: fakerootSchema,