feat(convert): add derive macros for To and FromBytes

[ModProg]

closes #661.

• docs
• tests
• depend on extism-convert/extism-pdk-path feature in https://github.com/extism/rust-pdk feat: add convert derive macros rust-pdk#47

[zshipko]

Looks great - I have a commit where I changed some of the tests to use this and it makes the developer experience very nice! Those changes are here: https://github.com/extism/extism/tree/test-convert-derive-macros

I'm not 100% clear how the right way to do the path resolution in this case, but I think your solution works pretty well - as long as the end user doesn't need to add any additional features when using the extism or extism-pdk crates.

I think we just need some more tests and documentation (like you mentioned in your issue) and it should be ready!

[ModProg]

as long as the end user doesn't need to add any additional features when using the extism or extism-pdk crates

Yeah, that is the idea. This would need to be extended for any “entry point” crates that are created in the future. But sadly, rust still doesn't have a $crate for proc macros.

[zshipko]

Hey @ModProg - how's this going? If you're stuck on the documentation/testing I can help pick some of that up next week.

[ModProg]

These will only be relevant as soon as proc macros are used inside this crate. So not yet. But this will avoid any future confusion.

[ModProg]

This makes the convert crate show up as a module instead of a reexport. This makes the paths inside the examples correct.

[ModProg]

Hey @ModProg - how's this going? If you're stuck on the documentation/testing I can help pick some of that up next week.

I added some, but feel free to expand on them.

[ModProg]

Alternatively, we could add a hidden # mod extism {pub use extism_convert as convert;} to the doc tests.

[ModProg]

The last two commits feel a bit like hacks to make ci happy :D

[zshipko]

The last two commits feel a bit like hacks to make ci happy :D

Ah yeah the path resolution features seem to add some additional complexity around docs/testing but it seems worth it.

I think these changes looks great and appreciate the effort updating the docs! I will merge this later after I experiment with the changes a little more.