How to actually resolve the copyWith deprecation warnings?

[camerow]

Heeding the warning from my linter, I've upgraded to using libprotoc 3.15.8 and protoc_plugin 20.0.0 to generate my foo.pb.dart files in the hopes that copyWith will no longer be used in my generated files and I can future proof my application, as well as hopefully reduce bundle size.

However generating my files simply adds deprecation annotations, but doesn't use the recommended method GeneratedMessageGenericExtensions.deepCopy. Am I missing something obvious to fix this deprecated method usage? AFAIK the plugin should be doing this for me when I generate these files.

My current Dart/Flutter:

Flutter 2.0.5 • channel stable • https://github.com/flutter/flutter.git
Framework • revision adc687823a (4 days ago) • 2021-04-16 09:40:20 -0700
Engine • revision b09f014e96
Tools • Dart 2.12.3

Thanks in advance for your guidance! I must add that up until now this has been working amazingly and I'm super thankful for this package.

[yang-lile]

I can't found any good way to fix update. So I only copy my test code to you for reference.

void main(List<String> args) {
  var ruler = StaticDataPool.rulers[0];
  var any = Any(value: ruler.data.value, typeUrl: ruler.data.typeUrl);
  print(any.canUnpackInto(RulerId.getDefault()));
  var unpackInto = any.unpackInto(RulerId());

  // older copy
  var copyWith = unpackInto.clone();
  copyWith = unpackInto.copyWith((a) {
    a.ruleName = '.scdae';
  });

  // new copy
  var newData =
      GeneratedMessageGenericExtensions<RulerId>(unpackInto).deepCopy();
  newData = GeneratedMessageGenericExtensions<RulerId>(unpackInto)
      .rebuild((unpackInto) {
    unpackInto.ruleName = 'cdsce';
  });
}

[osa1]

However generating my files simply adds deprecation annotations, but doesn't use the recommended method GeneratedMessageGenericExtensions.deepCopy

I'm guessing you meant rebuild not deepCopy, as that's what the deprecation message suggests.

I don't know why generated copyWith methods use the deprecated GeneratedMessage.copyWith, but the commit that deprecated GeneratedMessage.copyWith (6ed458c) also started generating // ignore: deprecated_member_uses next to uses of this method in generated code. So unless you're using copyWith in your code you shouldn't get any warnings.

Are you sure you're not using copyWith in your code?

[MuZhou233]

I recently facing to the same problem and confused about the warning. After a deep dive, I believe the point is the document and/or warning message didn't mention I need to import protobuf to use that extention (see https://github.com/google/protobuf.dart/pull/317/files#r848295229). protobuf is even not an dependency in my project before (I generate code in another place).

One major gotcha is that if you import your proto files with a prefix these
methods will not appear on your instances.
Alternatively you can add

import 'package:protobuf/protobuf.dart' show GeneratedMessageGenericExtensions;

@osa1 sorry for ping. I think it can helps a lot if you could provide more guidance here/or somewhere else.

[osa1]

@MuZhou233 I think we should export the extension in the generated files. I've implemented this in #907.

The PR (and a release) may have to wait until the next year as some of the devs are on vacation, and we may also want to finish and include #905 in the release as well.