testing/protocmp: automatically promote message values
For user convenience, automatically transform message values by
shallow copying them if necessary. Storing messages as values is
frowned upon, but is sometimes done by APIs that a user does not own.
Change-Id: I7e927d1a1e050bf4cea1aa889f56d23e99355f26
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/221423
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/testing/protocmp/util_test.go b/testing/protocmp/util_test.go
index f9da7e5..6f41ba4 100644
--- a/testing/protocmp/util_test.go
+++ b/testing/protocmp/util_test.go
@@ -145,6 +145,65 @@
want: true,
}}...)
+ // Test message values.
+ tests = append(tests, []test{{
+ x: testpb.TestAllTypes{OptionalSint64: proto.Int64(1)},
+ y: testpb.TestAllTypes{OptionalSint64: proto.Int64(1)},
+ opts: cmp.Options{Transform()},
+ want: true,
+ }, {
+ x: testpb.TestAllTypes{OptionalSint64: proto.Int64(1)},
+ y: testpb.TestAllTypes{OptionalSint64: proto.Int64(2)},
+ opts: cmp.Options{Transform()},
+ want: false,
+ }, {
+ x: struct{ M testpb.TestAllTypes }{M: testpb.TestAllTypes{OptionalSint64: proto.Int64(1)}},
+ y: struct{ M testpb.TestAllTypes }{M: testpb.TestAllTypes{OptionalSint64: proto.Int64(1)}},
+ opts: cmp.Options{Transform()},
+ want: true,
+ }, {
+ x: struct{ M testpb.TestAllTypes }{M: testpb.TestAllTypes{OptionalSint64: proto.Int64(1)}},
+ y: struct{ M testpb.TestAllTypes }{M: testpb.TestAllTypes{OptionalSint64: proto.Int64(2)}},
+ opts: cmp.Options{Transform()},
+ want: false,
+ }, {
+ x: struct{ M []testpb.TestAllTypes }{M: []testpb.TestAllTypes{{OptionalSint64: proto.Int64(1)}}},
+ y: struct{ M []testpb.TestAllTypes }{M: []testpb.TestAllTypes{{OptionalSint64: proto.Int64(1)}}},
+ opts: cmp.Options{Transform()},
+ want: true,
+ }, {
+ x: struct{ M []testpb.TestAllTypes }{M: []testpb.TestAllTypes{{OptionalSint64: proto.Int64(1)}}},
+ y: struct{ M []testpb.TestAllTypes }{M: []testpb.TestAllTypes{{OptionalSint64: proto.Int64(2)}}},
+ opts: cmp.Options{Transform()},
+ want: false,
+ }, {
+ x: struct {
+ M map[string]testpb.TestAllTypes
+ }{
+ M: map[string]testpb.TestAllTypes{"k": {OptionalSint64: proto.Int64(1)}},
+ },
+ y: struct {
+ M map[string]testpb.TestAllTypes
+ }{
+ M: map[string]testpb.TestAllTypes{"k": {OptionalSint64: proto.Int64(1)}},
+ },
+ opts: cmp.Options{Transform()},
+ want: true,
+ }, {
+ x: struct {
+ M map[string]testpb.TestAllTypes
+ }{
+ M: map[string]testpb.TestAllTypes{"k": {OptionalSint64: proto.Int64(1)}},
+ },
+ y: struct {
+ M map[string]testpb.TestAllTypes
+ }{
+ M: map[string]testpb.TestAllTypes{"k": {OptionalSint64: proto.Int64(2)}},
+ },
+ opts: cmp.Options{Transform()},
+ want: false,
+ }}...)
+
// Test IgnoreUnknown.
raw := pack.Message{
pack.Tag{1, pack.BytesType}, pack.String("Hello, goodbye!"),
diff --git a/testing/protocmp/xform.go b/testing/protocmp/xform.go
index e27c890..a42bf9b 100644
--- a/testing/protocmp/xform.go
+++ b/testing/protocmp/xform.go
@@ -161,10 +161,18 @@
// NOTE: There are currently no custom options for Transform,
// but the use of an unexported type keeps the future open.
+ // addrType returns a pointer to t if t isn't a pointer or interface.
+ addrType := func(t reflect.Type) reflect.Type {
+ if k := t.Kind(); k == reflect.Interface || k == reflect.Ptr {
+ return t
+ }
+ return reflect.PtrTo(t)
+ }
+
// TODO: Should this transform protoreflect.Enum types to Enum as well?
return cmp.FilterPath(func(p cmp.Path) bool {
ps := p.Last()
- if isMessageType(ps.Type()) {
+ if isMessageType(addrType(ps.Type())) {
return true
}
@@ -175,11 +183,19 @@
if !vx.IsValid() || vx.IsNil() || !vy.IsValid() || vy.IsNil() {
return false
}
- return isMessageType(vx.Elem().Type()) && isMessageType(vy.Elem().Type())
+ return isMessageType(addrType(vx.Elem().Type())) && isMessageType(addrType(vy.Elem().Type()))
}
return false
}, cmp.Transformer("protocmp.Transform", func(v interface{}) Message {
+ // For user convenience, shallow copy the message value if necessary
+ // in order for it to implement the message interface.
+ if rv := reflect.ValueOf(v); rv.IsValid() && rv.Kind() != reflect.Ptr && !isMessageType(rv.Type()) {
+ pv := reflect.New(rv.Type())
+ pv.Elem().Set(rv)
+ v = pv.Interface()
+ }
+
m := protoimpl.X.MessageOf(v)
switch {
case m == nil:
