$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
$ rustup update
$ rustup -V
rustup 1.24.3 (ce5817a94 2021-05-31)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.55.0 (c8dfcfe04 2021-09-06)`

$ cargo install wasm-pack

$ wasm-pack new hello-wasm
$ cd hello-wasm
$ wasm-pack build

Running headless tests in Firefox on `http://127.0.0.1:60110/`
Try find `webdriver.json` for configure browser's capabilities:
Not found

[package]
name = "hello-wasm"
version = "0.1.0"
authors = ["akabeko <sample@example.com>"]
edition = "2018"

[lib]
crate-type = ["cdylib", "rlib"]

[features]
default = ["console_error_panic_hook"]

[dependencies]
wasm-bindgen = "0.2.63"

# The `console_error_panic_hook` crate provides better debugging of panics by
# logging them with `console.error`. This is great for development, but requires
# all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
# code size when deploying.
console_error_panic_hook = { version = "0.1.6", optional = true }

# `wee_alloc` is a tiny allocator for wasm that is only ~1K in code size
# compared to the default allocator's ~10K. It is slower than the default
# allocator, however.
#
# Unfortunately, `wee_alloc` requires nightly Rust when targeting wasm for now.
wee_alloc = { version = "0.4.5", optional = true }

[dev-dependencies]
wasm-bindgen-test = "0.3.13"

[profile.release]
# Tell `rustc` to optimize for small code size.
opt-level = "s"

mod utils;

use wasm_bindgen::prelude::*;

// When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
// allocator.
#[cfg(feature = "wee_alloc")]
#[global_allocator]
static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;

#[wasm_bindgen]
extern {
    fn alert(s: &str);
}

#[wasm_bindgen]
pub fn greet() {
    alert("Hello, hello-wasm!");
}

mod utils;

use wasm_bindgen::prelude::*;

// When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
// allocator.
#[cfg(feature = "wee_alloc")]
#[global_allocator]
static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;

#[wasm_bindgen]
extern {
    fn alert(s: &str);
}

#[wasm_bindgen]
pub fn greet() {
    alert("Hello, hello-wasm!");
}

$ npm init rust-webpack my-app

$ npm start

Hello world!
[WDS] Live Reloading enabled.

# You must change these to your own details.
[package]
name = "rust-webpack-template"
description = "My super awesome Rust, WebAssembly, and Webpack project!"
version = "0.1.0"
authors = ["You <you@example.com>"]
categories = ["wasm"]
readme = "README.md"
edition = "2018"

[lib]
crate-type = ["cdylib"]

[profile.release]
# This makes the compiled code faster and smaller, but it makes compiling slower,
# so it's only enabled in release mode.
lto = true

[features]
# If you uncomment this line, it will enable `wee_alloc`:
#default = ["wee_alloc"]

[dependencies]
# The `wasm-bindgen` crate provides the bare minimum functionality needed
# to interact with JavaScript.
wasm-bindgen = "0.2.45"

# `wee_alloc` is a tiny allocator for wasm that is only ~1K in code size
# compared to the default allocator's ~10K. However, it is slower than the default
# allocator, so it's not enabled by default.
wee_alloc = { version = "0.4.2", optional = true }

# The `web-sys` crate allows you to interact with the various browser APIs,
# like the DOM.
[dependencies.web-sys]
version = "0.3.22"
features = ["console"]

# The `console_error_panic_hook` crate provides better debugging of panics by
# logging them with `console.error`. This is great for development, but requires
# all the `std::fmt` and `std::panicking` infrastructure, so it's only enabled
# in debug mode.
[target."cfg(debug_assertions)".dependencies]
console_error_panic_hook = "0.1.5"

# These crates are used for running unit tests.
[dev-dependencies]
wasm-bindgen-test = "0.2.45"
futures = "0.1.27"
js-sys = "0.3.22"
wasm-bindgen-futures = "0.3.22"

use wasm_bindgen::prelude::*;
use web_sys::console;


// When the `wee_alloc` feature is enabled, this uses `wee_alloc` as the global
// allocator.
//
// If you don't want to use `wee_alloc`, you can safely delete this.
#[cfg(feature = "wee_alloc")]
#[global_allocator]
static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;


// This is like the `main` function, except for JavaScript.
#[wasm_bindgen(start)]
pub fn main_js() -> Result<(), JsValue> {
    // This provides better error messages in debug mode.
    // It's disabled in release mode so it doesn't bloat up the file size.
    #[cfg(debug_assertions)]
    console_error_panic_hook::set_once();


    // Your code goes here!
    console::log_1(&JsValue::from_str("Hello world! Sample!"));

    Ok(())
}

import * as wasm from "./index_bg.wasm";
export * from "./index_bg.js";
wasm.__wbindgen_start();