Question: state of Extension API in Deno 1.11

[jeffreyjw]

I know the extension API is unstable and that there are currently issues about problems with it

#10671 #10534

This issue is more of a question: is there any way for Deno 1.11.2 to actually create a working native extension? The example code in https://github.com/denoland/deno/tree/main/test_plugin causes a segfault (at least on linux), the only way that I was able to have a plugin that does not crash is to not use any args struct and any zero copy struct, and to return a primitive like i32, like this:

use deno_core::Extension;
use deno_core::op_sync;
use deno_core::OpState;
use deno_core::ZeroCopyBuf;
use deno_core::error::AnyError;
use serde::Deserialize;

#[no_mangle]
pub fn init() -> Extension {
    println!("Initializing hello_world extension...");
    Extension::builder()
        .ops(vec![
            ("hello_world", op_sync(hello_world))
        ])
        .build()
}

#[derive(Debug, Deserialize)]
struct HelloWorldArgs {
    example: i32,
}

fn hello_world(
    _state: &mut OpState,
    // args: HelloWorldArgs,
    _: (),
    // _zero_copy: Option<ZeroCopyBuf>
    _: ()
) -> Result<i32, AnyError> {
    // format!("Hello rust world {}!", args.example);
    return Ok(42);
}

const pluginRid = Deno.openPlugin("./target/debug/libtest.so");
const {
    hello_world,
} = (Deno as any).core.ops();
const result = (Deno as any).core.opSync(hello_world, null, null);

But anything more, like returning a String, adding zerocopy or args other than a unit struct causes either a segmentation fault or an assertion error.

Is there ANY way to have a working extension in the current state of Deno? If not, is there any estimation (even a rough one without any promises) when writing extensions will be again possible?

[crowlKats]

No. plugins will go away in favour of FFI. See #8490/#10908. There is currently no ETA, but ideally 1.12 for FFI, as that's when plugins get removed.