migrate Optional<T> -> "T?"

[fzyzcjy]

Hi thanks for the lib! Since now null safety is stable, we want to migrate all Optional<T> to T?. Can this be done with some tools? Thanks

[cbracken]

Unfortunately we don't have any tools to automatically migrate Optional<T>s to T?. It could be done by using the analyzer package.

There are a few bits to be careful of. Specifically:

1. The transform and transformNullable methods.
2. Dealing with the fact that Optional<T> implements Iterable<T>. This allows Optionals to be elided when used in an iterable context such that, for example [Optional<int>.of(1), Optional<int>.absent(), Optional<int>.of(2)].expand((i) => i) results in [1, 2]. See: Make Optional implement Iterable #289

If you or anyone else were keen to implement such a thing in a tested way, I think we'd be glad to point people to it in the docs for Optional, or add it as a tool under a bin directory.

[SShayashi]

Are there any new updates?
The latest Flutter 3.10 adopts Dart3 and only allows null safety code to be executed.
Many developers will be looking for a migration tool.

[fzyzcjy]

I personally migrated it (2 years ago) using hacky regular expressions...

[cbracken]

No updates. None of the authors currently have time to write such a tool, but as I say, we'd gladly point people to a tool if someone else were to write one. I'm going to close this issue as this isn't on the roadmap.