Merge pull request #191 from mercari/support-null-value

Support null value

_examples/02_simple/main_test.go

@@ -311,7 +311,10 @@ func TestFederation(t *testing.T) {
 		BoolWrapperValue: &wrapperspb.BoolValue{
 			Value: true,
 		},
-		Hello: "hello\nworld",
+		Hello:          "hello\nworld",
+		NullTimestamp:  nil,
+		NullTimestamp2: nil,
+		NullTimestamp3: nil,
 	}, cmpopts.IgnoreUnexported(
 		federation.GetPostResponse{},
 		federation.Post{},

_examples/02_simple/proto/federation/federation.proto

@@ -4,6 +4,7 @@ package federation;
 
 import "google/protobuf/any.proto";
 import "google/protobuf/wrappers.proto";
+import "google/protobuf/timestamp.proto";
 import "grpc/federation/federation.proto";
 import "post/post.proto";
 import "user/user.proto";
@@ -38,6 +39,7 @@ message GetPostResponse {
     def { name: "sorted_values" by: "[4, 1, 3, 2].sortAsc(v, v)" }
     def { name: "sorted_items" by: "[user.Item{location:user.Item.Location{addr1:'a'}}, user.Item{location:user.Item.Location{addr1:'b'}}].sortDesc(v, v.location.addr1)" }
     def { name: "map_value" by : "{1: 'a', 2: 'b', 3: 'c'}" }
+    def { name: "null_value" by: "null" }
   };
   Post post = 1 [(grpc.federation.field).by = "post"];
   string str = 2 [(grpc.federation.field).string = "hello"];
@@ -66,6 +68,9 @@ message GetPostResponse {
   google.protobuf.StringValue string_wrapper_value = 25 [(grpc.federation.field).by = "google.protobuf.StringValue{value: 'hello'}"];
   google.protobuf.BytesValue bytes_wrapper_value = 26 [(grpc.federation.field).by = "google.protobuf.BytesValue{value: bytes('world')}"];
   string hello = 27 [(grpc.federation.field).by = "'hello\\nworld'"];
+  google.protobuf.Timestamp null_timestamp = 28 [(grpc.federation.field).by = "null"];
+  google.protobuf.Timestamp null_timestamp2 = 29 [(grpc.federation.field).by = "null_value"];
+  google.protobuf.Timestamp null_timestamp3 = 30 [(grpc.federation.field).by = "true ? null : google.protobuf.Timestamp{}"];
 }
 
 message A {

generator/code_generator.go

@@ -813,7 +813,7 @@ func toCELTypeDeclare(t *resolver.Type) string {
 }
 
 func (f *File) toTypeText(t *resolver.Type) string {
-	if t == nil {
+	if t == nil || t.IsNull {
 		return "any"
 	}
 	if t.OneofField != nil {
@@ -2829,6 +2829,9 @@ func toCELNativeType(t *resolver.Type) string {
 		cloned.Repeated = false
 		return fmt.Sprintf("grpcfed.CELListType(%s)", toCELNativeType(cloned))
 	}
+	if t.IsNull {
+		return "grpcfed.CELNullType"
+	}
 	switch t.Kind {
 	case types.Double, types.Float:
 		return "grpcfed.CELDoubleType"

grpc/federation/alias.go

@@ -44,6 +44,7 @@ var (
 	CELObjectType         = cel.ObjectType
 	CELListType           = cel.ListType
 	CELMapType            = cel.MapType
+	CELNullType           = cel.NullType
 	NewCELListType        = types.NewListType
 	NewCELObjectType      = types.NewObjectType
 )

grpc/federation/cel.go

@@ -684,6 +684,12 @@ func EvalCEL(ctx context.Context, req *EvalCELRequest) (any, error) {
 		}
 		out = opt.GetValue()
 	}
+	if _, ok := out.(celtypes.Null); ok {
+		if req.OutType == nil {
+			return nil, nil
+		}
+		return reflect.Zero(req.OutType).Interface(), nil
+	}
 	if req.OutType != nil {
 		return out.ConvertToNative(req.OutType)
 	}

grpc/federation/generator/decode.go

@@ -1711,6 +1711,7 @@ func (d *decoder) toType(t *plugin.Type) (*resolver.Type, error) {
 	return &resolver.Type{
 		Kind:       d.toTypeKind(t.GetKind()),
 		Repeated:   t.GetRepeated(),
+		IsNull:     t.GetIsNull(),
 		Message:    msg,
 		Enum:       enum,
 		OneofField: oneofField,

grpc/federation/generator/encode.go

@@ -574,6 +574,7 @@ func (e *encoder) toType(t *resolver.Type) *plugin.Type {
 	ret := &plugin.Type{
 		Kind:     e.toTypeKind(t.Kind),
 		Repeated: t.Repeated,
+		IsNull:   t.IsNull,
 	}
 	switch {
 	case t.Message != nil:

proto/grpc/federation/generator.proto

@@ -255,10 +255,11 @@ enum TypeKind {
 message Type {
   TypeKind kind = 1;
   bool repeated = 2;
+  bool is_null = 3;
   oneof ref {
-    string message_id = 3;
-    string enum_id = 4;
-    string oneof_field_id = 5;
+    string message_id = 4;
+    string enum_id = 5;
+    string oneof_field_id = 6;
   }
 }
 

resolver/resolver.go

@@ -3390,6 +3390,8 @@ func (r *Resolver) fromCELType(ctx *context, typ *cel.Type) (*Type, error) {
 			return &Type{Kind: types.Enum, Enum: enum}, nil
 		}
 		return r.fromCELType(ctx, param)
+	case celtypes.NullTypeKind:
+		return NullType, nil
 	}
 
 	return nil, fmt.Errorf("unknown type %s is required", typ.TypeName())
@@ -3932,6 +3934,9 @@ func isDifferentType(from, to *Type) bool {
 	if from.IsNumber() && to.IsNumber() {
 		return false
 	}
+	if from.IsNull && (to.Repeated || to.Kind == types.Message || to.Kind == types.Bytes) {
+		return false
+	}
 	return from.Kind != to.Kind
 }
 

resolver/type_conversion.go

@@ -14,6 +14,9 @@ func typeConversionDecls(fromType, toType *Type, convertedFQDNMap map[string]str
 	if fromType == nil || toType == nil {
 		return nil
 	}
+	if fromType.IsNull || toType.IsNull {
+		return nil
+	}
 	if !requiredTypeConversion(fromType, toType) {
 		return nil
 	}

resolver/types.go

@@ -348,6 +348,7 @@ type MessageDependencyGraphNode struct {
 
 type Type struct {
 	Kind       types.Kind
+	IsNull     bool
 	Repeated   bool
 	Message    *Message
 	Enum       *Enum
@@ -358,6 +359,7 @@ func (t *Type) Clone() *Type {
 	return &Type{
 		Kind:       t.Kind,
 		Repeated:   t.Repeated,
+		IsNull:     t.IsNull,
 		Message:    t.Message,
 		Enum:       t.Enum,
 		OneofField: t.OneofField,
@@ -484,6 +486,7 @@ var (
 	BytesType            = &Type{Kind: types.Bytes}
 	EnumType             = &Type{Kind: types.Enum}
 	EnvType              = &Type{Kind: types.String}
+	NullType             = &Type{IsNull: true}
 	DoubleRepeatedType   = &Type{Kind: types.Double, Repeated: true}
 	FloatRepeatedType    = &Type{Kind: types.Float, Repeated: true}
 	Int32RepeatedType    = &Type{Kind: types.Int32, Repeated: true}

types/types.go

@@ -89,7 +89,7 @@ func (k Kind) ToString() string {
 	case Sint64:
 		return "sint64"
 	}
-	return ""
+	return "null"
 }
 
 func ToKind(s string) Kind {

validator/validator_test.go

@@ -425,9 +425,6 @@ testdata/invalid_message_name.proto:53:17: "post.Invalid" message does not exist
 testdata/invalid_message_name.proto:54:17: undefined message specified
 54:            name: "post.Invalid"
                      ^
-testdata/invalid_message_name.proto:63:47: unknown type null_type is required
-63:    User user = 4 [(grpc.federation.field).by = "user1"];
-                                                   ^
 `},
 		{file: "invalid_nested_message_name.proto", expected: `
 testdata/invalid_nested_message_name.proto:36:31: "federation.Invalid1" message does not exist
@@ -442,12 +439,12 @@ testdata/invalid_nested_message_name.proto:42:33: "federation.Invalid2" message
 testdata/invalid_nested_message_name.proto:42:41: undefined message specified
 42:            { name: "c1" message: { name: "Invalid2" } }
                                              ^
-testdata/invalid_nested_message_name.proto:45:51: unknown type null_type is required
+testdata/invalid_nested_message_name.proto:45:7: cannot convert type automatically: field type is "string" but specified value type is "null"
 45:        string c1 = 1 [(grpc.federation.field).by = "c1"];
-                                                       ^
-testdata/invalid_nested_message_name.proto:47:49: unknown type null_type is required
+           ^
+testdata/invalid_nested_message_name.proto:47:5: cannot convert type automatically: field type is "string" but specified value type is "null"
 47:      string b1 = 1 [(grpc.federation.field).by = "b1"];
-                                                     ^
+         ^
 `},
 		{file: "invalid_message_argument.proto", expected: `
 testdata/invalid_message_argument.proto:51:19: ERROR: <input>:1:11: type 'string' does not support field selection