# rspack_binding_builder_macros
Exports a few macros to help you create a custom plugin register with Rspack.
## Important
This crate is used for creating a custom binding. It is not intended to be used directly by non-custom binding users.
## Guide
[Rspack Custom binding](https://rspack-contrib.github.io/rspack-rust-book/custom-binding/getting-started/index.html)
## Usage
### register_plugin
Create a custom plugin register with Rspack.
The created plugin register will be exposed to the final N-API binding.
The plugin needs to be wrapped with `require('@rspack/core').experiments.createNativePlugin`
to be used in the host.
#### Parameters
`register_plugin` macro accepts two arguments:
- The name of the plugin
- A resolver function that returns a `rspack_core::BoxPlugin`
The resolver function accepts two arguments:
- `env`: The environment of the plugin, it is the same as `napi::bindgen_prelude::Env`
- `options`: The options of the plugin, it is the same as `napi::bindgen_prelude::Unknown<'_>`
The resolver function should return a `rspack_core::BoxPlugin`
#### Example
This example will expose `registerMyBannerPlugin` in the final N-API binding:
> **Note:** The following example requires the `napi_derive`, `rspack_binding_builder_macros`, `rspack_core`, and `rspack_error` crates, and is for illustration only. It may not compile without additional setup.
```rust,ignore
use napi_derive::napi;
use rspack_binding_builder_macros::register_plugin;
register_plugin!(
"MyBannerPlugin",
|env: napi::bindgen_prelude::Env, options: napi::bindgen_prelude::Unknown<'_>| {
Ok(Box::new(MyBannerPlugin) as rspack_core::BoxPlugin)
}
);
#[derive(Debug)]
struct MyBannerPlugin;
impl rspack_core::Plugin for MyBannerPlugin {
fn apply(&self, ctx: &mut rspack_core::ApplyContext<'_>) -> rspack_error::Result<()> {
Ok(())
}
}
```
The `registerMyBannerPlugin` function will be exposed to the final N-API binding.
```js
const { registerMyBannerPlugin } = require("your-custom-binding");
const plugin = registerMyBannerPlugin();
```
To actually use the plugin, you need to wrap it with `require('@rspack/core').experiments.createNativePlugin`:
```js
require("@rspack/core").experiments.createNativePlugin(
"MyBannerPlugin",
options => options
);
```