Add an option to enable field mask override (#183)

* Add an option to enable field mask override

* Implement option pattern for PresenceClientInterceptor
* Add WithOverrideFieldMask option to enable field mask override

* Fix minor issues

* provide test to override option

* add test for multiple field masks

gateway/field_presence.go

@@ -68,7 +68,7 @@ func NewPresenceAnnotator(methods ...string) func(context.Context, *http.Request
 					if m, ok := item.node.(map[string]interface{}); ok {
 						// if the item is an object, then enqueue all of its children
 						for k, v := range m {
-							newPath := extendPath(item.path, k, v)
+							newPath := extendPath(item.path, k)
 							queue = append(queue, pathItem{path: newPath, node: v})
 						}
 					}
@@ -87,9 +87,9 @@ func NewPresenceAnnotator(methods ...string) func(context.Context, *http.Request
 	}
 }
 
-func extendPath(parrent []string, key string, value interface{}) []string {
-	newPath := make([]string, len(parrent)+1)
-	copy(newPath, parrent)
+func extendPath(parent []string, key string) []string {
+	newPath := make([]string, len(parent)+1)
+	copy(newPath, parent)
 	newPath[len(newPath)-1] = generator.CamelCase(key)
 	return newPath
 }
@@ -145,9 +145,26 @@ type pathItem struct {
 	node interface{}
 }
 
+type presenceInterceptorOptionsDecorator struct {
+	overrideFieldMask bool
+}
+
+type presenceInterceptorOption func(*presenceInterceptorOptionsDecorator)
+
+//WithOverrideFieldMask represent an option to override field mask generated by grpc-gateway
+func WithOverrideFieldMask(d *presenceInterceptorOptionsDecorator) {
+	d.overrideFieldMask = true
+}
+
 // PresenceClientInterceptor gets the interceptor for populating a fieldmask in a
 // proto message from the fields given in the metadata/context
-func PresenceClientInterceptor() grpc.UnaryClientInterceptor {
+func PresenceClientInterceptor(options ...presenceInterceptorOption) grpc.UnaryClientInterceptor {
+	ops := &presenceInterceptorOptionsDecorator{}
+
+	for _, op := range options {
+		op(ops)
+	}
+
 	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) (err error) {
 		defer func() {
 			err = invoker(ctx, method, req, reply, cc, opts...)
@@ -175,8 +192,12 @@ func PresenceClientInterceptor() grpc.UnaryClientInterceptor {
 
 		for i := 0; i < t.NumField(); i++ {
 			f := t.Field(i)
-			if f.Type() == reflect.TypeOf(fieldMask) && f.IsNil() {
-				f.Set(reflect.ValueOf(fieldMask))
+			if f.Type() == reflect.TypeOf(fieldMask) {
+				if ops.overrideFieldMask || f.IsNil() {
+					f.Set(reflect.ValueOf(fieldMask))
+				}
+
+				return
 			}
 		}
 		return

gateway/field_presence_test.go

@@ -157,3 +157,100 @@ func TestUnaryServerInterceptor(t *testing.T) {
 		}
 	})
 }
+
+type RequestWithFieldMask struct {
+	FieldMask *field_mask.FieldMask
+}
+
+func TestOverrideFieldMaskOption(t *testing.T) {
+	defaultInvoker := func(context.Context, string, interface{}, interface{}, *grpc.ClientConn, ...grpc.CallOption) error {
+		return nil
+	}
+
+	f := func(ctx context.Context, req *RequestWithFieldMask, expected *field_mask.FieldMask, overrideEnabled bool) {
+		interceptor := PresenceClientInterceptor()
+		if overrideEnabled {
+			interceptor = PresenceClientInterceptor(WithOverrideFieldMask)
+		}
+
+		if err := interceptor(ctx, "", req, nil, nil, defaultInvoker); err != nil {
+			t.Logf("Unexpected error %s\n", err)
+			t.Fail()
+		}
+
+		result := req.FieldMask
+
+		if !isEqualFieldMasks(expected.Paths, result.Paths) {
+			t.Logf("Unexpected result field mask, expect %+v, got %+v\n", expected.Paths, result.Paths)
+			t.Fail()
+		}
+
+	}
+
+	r1 := &RequestWithFieldMask{FieldMask: &field_mask.FieldMask{Paths: []string{"One"}}}
+	f(context.Background(), r1, &field_mask.FieldMask{Paths: []string{"One"}}, true)
+
+	ctx := metadata.NewIncomingContext(context.Background(), metadata.MD{fieldPresenceMetaKey: []string{"One"}})
+	r2 := &RequestWithFieldMask{}
+	f(ctx, r2, &field_mask.FieldMask{Paths: []string{"One"}}, true)
+
+	ctx = metadata.NewIncomingContext(context.Background(), metadata.MD{fieldPresenceMetaKey: []string{"Two"}})
+	r3 := &RequestWithFieldMask{FieldMask: &field_mask.FieldMask{Paths: []string{"One"}}}
+	f(ctx, r3, &field_mask.FieldMask{Paths: []string{"Two"}}, true)
+
+	ctx = metadata.NewIncomingContext(context.Background(), metadata.MD{fieldPresenceMetaKey: []string{"Two"}})
+	r4 := &RequestWithFieldMask{FieldMask: &field_mask.FieldMask{Paths: []string{"One"}}}
+	f(ctx, r4, &field_mask.FieldMask{Paths: []string{"One"}}, false)
+}
+
+type RequestWithMultiFieldMask struct {
+	FieldMasks []*field_mask.FieldMask
+}
+
+func TestOverrideMultipleFieldMasksOption(t *testing.T) {
+	defaultInvoker := func(context.Context, string, interface{}, interface{}, *grpc.ClientConn, ...grpc.CallOption) error {
+		return nil
+	}
+
+	f := func(ctx context.Context, req *RequestWithMultiFieldMask, expected []*field_mask.FieldMask, overrideEnabled bool) {
+		interceptor := PresenceClientInterceptor()
+		if overrideEnabled {
+			interceptor = PresenceClientInterceptor(WithOverrideFieldMask)
+		}
+
+		if err := interceptor(ctx, "", req, nil, nil, defaultInvoker); err != nil {
+			t.Logf("Unexpected error %s\n", err)
+			t.Fail()
+		}
+
+		result := req.FieldMasks
+		if len(result) != len(expected) {
+			t.Logf("Unexpected field masks expect %+v, got %+v", expected, result)
+			t.Fail()
+			return
+		}
+
+		for i := 0; i < len(expected); i++ {
+			if !isEqualFieldMasks(expected[i].Paths, result[i].Paths) {
+				t.Logf("Unexpected result field mask on index %d, expect %+v, got %+v\n", i, expected[0].Paths, result[0].Paths)
+				t.Fail()
+			}
+		}
+
+	}
+
+	r1 := &RequestWithMultiFieldMask{FieldMasks: []*field_mask.FieldMask{{Paths: []string{"One"}}, {Paths: []string{"Two"}}}}
+	f(context.Background(), r1, []*field_mask.FieldMask{{Paths: []string{"One"}}, {Paths: []string{"Two"}}}, true)
+
+	ctx := metadata.NewIncomingContext(context.Background(), metadata.MD{fieldPresenceMetaKey: []string{"One", "Two"}})
+	r2 := &RequestWithMultiFieldMask{}
+	f(ctx, r2, []*field_mask.FieldMask{{Paths: []string{"One"}}, {Paths: []string{"Two"}}}, true)
+
+	ctx = metadata.NewIncomingContext(context.Background(), metadata.MD{fieldPresenceMetaKey: []string{"Four", "Five"}})
+	r3 := &RequestWithMultiFieldMask{FieldMasks: []*field_mask.FieldMask{{Paths: []string{"One"}}, {Paths: []string{"Two"}}}}
+	f(ctx, r3, []*field_mask.FieldMask{{Paths: []string{"Four"}}, {Paths: []string{"Five"}}}, true)
+
+	ctx = metadata.NewIncomingContext(context.Background(), metadata.MD{fieldPresenceMetaKey: []string{"Four", "Five"}})
+	r4 := &RequestWithMultiFieldMask{FieldMasks: []*field_mask.FieldMask{{Paths: []string{"One"}}, {Paths: []string{"Two"}}}}
+	f(ctx, r4, []*field_mask.FieldMask{{Paths: []string{"One"}}, {Paths: []string{"Two"}}}, false)
+}