Only add wasm-bindgen as a dependency on wasm32-unknown-unknown

[emilk]

When setting the js feature, uuid would previously pull in all of wasm-bindgen even when targeting a native build:

❯ cargo tree -p uuid --target aarch64-apple-darwin --no-default-features --features js
uuid v1.7.0 (/Users/emilk/code/forks/uuid)
└── wasm-bindgen v0.2.91
    ├── cfg-if v1.0.0
    └── wasm-bindgen-macro v0.2.91 (proc-macro)
        ├── quote v1.0.35
        │   └── proc-macro2 v1.0.78
        │       └── unicode-ident v1.0.12
        └── wasm-bindgen-macro-support v0.2.91
            ├── proc-macro2 v1.0.78 (*)
            ├── quote v1.0.35 (*)
            ├── syn v2.0.48
            │   ├── proc-macro2 v1.0.78 (*)
            │   ├── quote v1.0.35 (*)
            │   └── unicode-ident v1.0.12
            ├── wasm-bindgen-backend v0.2.91
            │   ├── bumpalo v3.14.0
            │   ├── log v0.4.20
            │   ├── once_cell v1.19.0
            │   ├── proc-macro2 v1.0.78 (*)
            │   ├── quote v1.0.35 (*)
            │   ├── syn v2.0.48 (*)
            │   └── wasm-bindgen-shared v0.2.91
            └── wasm-bindgen-shared v0.2.91

Now all of that dependency tree is gone when building for native.

Note that a user (me) cannot set the js feature only for some targets, but must opt-in to it on all targets.

[KodrAus]

Thanks for the PR @emilk. It looks like this doesn't work with the written [target.'cfg(target = "wasm32-unknown-unknown")'.dependencies.wasm-bindgen] cfg, but does with this one:

[target.'cfg(all(target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown"))'.dependencies.wasm-bindgen]

I have no idea why 🙂

Would you be happy to use that bound for wasm-bindgen and for the dev-dependencies.wasm-bindgen too?

[emilk]

I'm happy with whatever works to get rid of the dependencies :)

Personally I prefer this format of my Cargo.toml:

[target.'cfg(target_arch = "wasm32")'.dependencies]
wasm-bindgen = { version = "0.2", optional = true }

(which works for me at least)

[emilk]

ok, let's see if that works

[KodrAus]

The build failure is unrelated. I just merged a fix to main for it so if you rebase things should go green here too 🙂

[emilk]

rebased

[KodrAus]

Thanks @emilk! I'll put together a release that includes this shortly.