# 📦✨  wasm-pack
> pack up the wasm and publish it to npm!

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the goal of this project is to create a portable command line tool
for publishing compiled wasm projects to the npm registry for the consumption
of js devs using the npm CLI, yarn, or any other CLI tool that interfaces
with the npm registry.

this project is a part of the [rust-wasm] group. you can find more info by
visiting that repo!

[rust-wasm]: https://github.com/rust-lang-nursery/rust-wasm/

## 🔮 prerequisities

this project is written in rust. [get rust] to work on this project.

[get rust]: https://www.rustup.rs/

## 🏃‍♀️ up and running

1. fork and clone this repository
2. `cd wasm-pack`
3. `cargo run`

## 💃 commands

- `help`: display available commands
- 🐣  `init`: create necessary files for js interop and npm publishing
  - optionally pass a path to a dir that contains a `Cargo.toml`, e.g.:
    `wasm-pack init examples/js-hello-world`
- 🍱  `pack`: create a tarball but don't push to the npm registry [NOT IMPLEMENTED]
- 🎆  `publish`: create a tarball and publish to the npm registry [NOT IMPLEMENTED]

## ⚙️  how to use

1. write a crate in Rust.
2. add `wasm-bindgen` to your `Cargo.toml`:

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

    [dependencies]
    wasm-bindgen = { git = 'https://github.com/alexcrichton/wasm-bindgen' }
  ```
3. add this to the top of your `src/lib.rs`:

  ```rust
    #![feature(proc_macro)]

    extern crate wasm_bindgen;

    use wasm_bindgen::prelude::*;
  ```

4. annotate your public functions with `#[wasm_bindgen]` and  `#[no_mangle]`, for example:

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

    #[wasm_bindgen]
    #[no_mangle]
    pub extern fn greet(name: &str) {
        alert(&format!("Hello, {}!", name));
    }
  ```

5. install this tool: `cargo install wasm-pack`
6. run `wasm-pack init`, optionally, pass a path to a dir that contains your `Cargo.toml`
7. this tool generates files in a `pkg` dir. to publish to npm, `cd pkg` and then `npm publish` 
  (in the future you'll be able to use this tool to publish)

[rust-wasm/36]: https://github.com/rust-lang-nursery/rust-wasm/issues/36
[wasm-bindgen]: https://github.com/alexcrichton/wasm-bindgen