Make ChannelTask public, but hidden in docu

[Roba1993]

So now I'm a bit late with a response :sweat_smile
Thank you very much for your rework and the release of the new version.
My problem with postcard were SerializeSeqLengthUnknown errors, which I have fixed right now.

Right now I need to have the ChannelTask creation available.
The reason is, sometimes I want to execute certain logic in the main thread or WebWorker. In this cases my custom logic needs the channel in the same way as when I work with WebWorker.
I understand, that this is quiet niche, so I hid the new function from the docs.

[Copilot]

Pull request overview

Exposes ChannelTask construction for niche advanced use cases while adding feature-gated serializer backends so the crate can use either postcard (default) or pot for message encoding/decoding.

Changes:

• Add mutually exclusive codec-postcard / codec-pot feature flags and implement to_bytes/from_bytes for both codecs.
• Make ChannelTask::new public but hidden from generated docs.
• Update dependencies and CI clippy job to validate both codec feature sets.

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/convert.rs	Adds postcard/pot codec implementations behind mutually exclusive feature flags and enforces selection via compile_error!.
src/channel_task.rs	Makes ChannelTask::new public (but #[doc(hidden)]) so users can construct tasks manually.
Cargo.toml	Makes postcard optional, adds optional pot, introduces codec features, and updates default features.
Cargo.lock	Records new dependency resolution including pot and its transitive deps.
.github/workflows/test.yml	Replaces --all-features clippy with two clippy runs (one per codec).

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[paberr]

Thanks for the PR!

One note: in it's current form, the codec change is breaking for users with default-features = false.
postcard was previously unconditional, and now they'd hit a compile_error!.

I wonder whether a better design would be to have postcard still enabled by default, and a pot feature that replaces it with pot?
The only downside I can think of is that postcard stays as a dependency even with codec-pot, that's a few extra KB.

[Roba1993]

I made the changes as requested by you. Only pot feature is totally fine for me. But it would mean with -all-features this is then the used codec. From my perspective perfect, because it's the codec I use. I just have seen you released v0.3.0 today. Too bad, I'm too late for that....

[paberr]

But it would mean with -all-features this is then the used codec. From my perspective perfect, because it's the codec I use.

Oh true, I didn't think about that. Let me think about what's the best method then.

I just have seen you released v0.3.0 today. Too bad, I'm too late for that....

Not a big issue, I'm happy to release new versions quickly. 😄

[paberr]

I thought about this more and think the following pattern might be the cleanest:

Make both codecs optional, with postcard taking priority when both are enabled:

  [features]
  default = ["serde", "codec-postcard"]
  codec-postcard = ["dep:postcard"]
  codec-pot = ["dep:pot"]

convert.rs

#[cfg(feature = "codec-postcard")]
pub fn to_bytes<T: Serialize>(value: &T) -> Box<[u8]> {
    postcard::to_allocvec(value).expect("WebWorker serialization failed").into()
}

#[cfg(all(feature = "codec-pot", not(feature = "codec-postcard")))]
pub fn to_bytes<T: Serialize>(value: &T) -> Box<[u8]> {
    POT_CONFIG.serialize(value).expect("WebWorker serialization failed").into()
}

#[cfg(not(any(feature = "codec-postcard", feature = "codec-pot")))]
compile_error!("No codec selected. Enable `codec-postcard` (default) or `codec-pot`.");

That combination gives us:

• Default → postcard (backward-compatible)
• default-features = false, features = ["codec-pot"] → pot
• --all-features → postcard (backwards-compatible)
• default-features = false → compile error
• postcard binary is only included when actually used, same for pot if properly configured

The compile_error! here is fine because it only fires when no codec is selected.

Also, can you rebase? After that change, I'll let CoPilot review it once more. If everything is fine, I'll merge and release.

[Roba1993]

Done, have a check and let me know :)

[Copilot]

Pull request overview

Copilot reviewed 3 out of 4 changed files in this pull request and generated 2 comments.

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[paberr]

Thanks a lot @Roba1993 !

[paberr]

It's part of the v0.4.0 release