Add json encoding opts to EncodeTypedValue (#747)

* Add json encoding opts to EncodeTypedValue

Author: DanG100

ygot/render.go

@@ -665,12 +665,26 @@ func leavesToNotifications(leaves map[*path]interface{}, ts int64, pfx *gnmiPath
 	return []*gnmipb.Notification{n}, nil
 }
 
+// EncodeTypedValueOpt is an interface implemented by arguments to
+// the EncodeTypedValueOpt function.
+type EncodeTypedValueOpt interface {
+	// IsMarshal7951Arg is a market method.
+	IsEncodeTypedValueOpt()
+}
+
 // EncodeTypedValue encodes val into a gNMI TypedValue message, using the specified encoding
 // type if the value is a struct.
-func EncodeTypedValue(val interface{}, enc gnmipb.Encoding) (*gnmipb.TypedValue, error) {
+func EncodeTypedValue(val interface{}, enc gnmipb.Encoding, opts ...EncodeTypedValueOpt) (*gnmipb.TypedValue, error) {
+	jc := &RFC7951JSONConfig{}
+	for _, opt := range opts {
+		if cfg, ok := opt.(*RFC7951JSONConfig); ok {
+			jc = cfg
+		}
+	}
+
 	switch v := val.(type) {
 	case GoStruct:
-		return marshalStruct(v, enc)
+		return marshalStruct(v, enc, jc)
 	case GoEnum:
 		en, err := EnumName(v)
 		if err != nil {
@@ -731,7 +745,7 @@ func EncodeTypedValue(val interface{}, enc gnmipb.Encoding) (*gnmipb.TypedValue,
 
 // marshalStruct encodes the struct s according to the encoding specified by enc. It
 // is returned as a TypedValue gNMI message.
-func marshalStruct(s GoStruct, enc gnmipb.Encoding) (*gnmipb.TypedValue, error) {
+func marshalStruct(s GoStruct, enc gnmipb.Encoding, cfg *RFC7951JSONConfig) (*gnmipb.TypedValue, error) {
 	if reflect.ValueOf(s).IsNil() {
 		return nil, nil
 	}
@@ -750,7 +764,8 @@ func marshalStruct(s GoStruct, enc gnmipb.Encoding) (*gnmipb.TypedValue, error)
 		}
 	case gnmipb.Encoding_JSON_IETF:
 		// We always prepend the module name when marshalling within a Notification.
-		j, err = ConstructIETFJSON(s, &RFC7951JSONConfig{AppendModuleName: true})
+		cfg.AppendModuleName = true
+		j, err = ConstructIETFJSON(s, cfg)
 		encfn = func(s string) *gnmipb.TypedValue {
 			return &gnmipb.TypedValue{Value: &gnmipb.TypedValue_JsonIetfVal{[]byte(s)}}
 		}
@@ -946,6 +961,10 @@ type RFC7951JSONConfig struct {
 // Marshal7951.
 func (*RFC7951JSONConfig) IsMarshal7951Arg() {}
 
+// IsEncodeTypedValueOpt marks the RFC7951JSONConfig struct as a valid option to
+// EncodeTypedValue.
+func (*RFC7951JSONConfig) IsEncodeTypedValueOpt() {}
+
 // ConstructIETFJSON marshals a supplied GoStruct to a map, suitable for
 // handing to json.Marshal. It complies with the convention for marshalling
 // to JSON described by RFC7951. The supplied args control options corresponding

ygot/render_test.go

@@ -3786,6 +3786,7 @@ func TestEncodeTypedValue(t *testing.T) {
 		name             string
 		inVal            interface{}
 		inEnc            gnmipb.Encoding
+		inArgs           []EncodeTypedValueOpt
 		want             *gnmipb.TypedValue
 		wantErrSubstring string
 	}{{
@@ -3907,6 +3908,18 @@ func TestEncodeTypedValue(t *testing.T) {
   "f2mod:config": {
     "f2": "hello"
   }
+}`)}},
+	}, {
+		name: "struct val - with PreferShadowPath",
+		inVal: &renderExample{
+			Str: String("test-string"),
+		},
+		inEnc: gnmipb.Encoding_JSON_IETF,
+		inArgs: []EncodeTypedValueOpt{
+			&RFC7951JSONConfig{PreferShadowPath: true},
+		},
+		want: &gnmipb.TypedValue{Value: &gnmipb.TypedValue_JsonIetfVal{[]byte(`{
+  "srt": "test-string"
 }`)}},
 	}, {
 		name: "struct val - internal json",
@@ -3941,7 +3954,7 @@ func TestEncodeTypedValue(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := EncodeTypedValue(tt.inVal, tt.inEnc)
+			got, err := EncodeTypedValue(tt.inVal, tt.inEnc, tt.inArgs...)
 			if diff := errdiff.Substring(err, tt.wantErrSubstring); diff != "" {
 				t.Fatalf("did not get expected error, %s", diff)
 			}