| # `@next/swc` | |
| This package is responsible for swc compilation customized for next.js | |
| ### Development | |
| Run tests | |
| ```sh | |
| cargo test | |
| # Update snapshots and fixtures for tests | |
| UPDATE=1 cargo test | |
| ``` | |
| Format code before submitting code | |
| ``` | |
| cargo fmt | |
| ``` | |
| Build the binary to integrate with next.js | |
| ``` | |
| pnpm build-native | |
| ``` | |
| Build wasm bindings to integrate with next.js | |
| ``` | |
| pnpm build-wasm | |
| ``` | |
| ### napi bindings feature matrix | |
| Due to platform differences napi bindings selectively enables supported features. | |
| See below tables for the currently enabled features. | |
| | arch\platform | Linux(gnu) | Linux(musl) | Darwin | Windows | | |
| | ------------- | ---------- | ----------- | --------- | --------- | | |
| | x64 | a,b,d,e,f | a,b,d,e,f | a,b,d,e,f | a,b,d,e,f | | |
| | aarch64 | a,d,e,f | a,d,e,f | a,b,d,e,f | a,b,c,e | | |
| - a: `turbo_tasks_malloc` | |
| - b: `turbo_tasks_malloc_custom_allocator` | |
| - c: `native-tls` (via `turbo-tasks-fetch`) | |
| - d: `rustls-tls` (via `turbo-tasks-fetch`) | |
| - e: `image-extended` (webp) | |
| - f: `plugin` | |
| ### Package hierarchies | |
| `@next/swc` consist of multiple rust packages to enable features. See below for the high level hierarchies. | |
| ```mermaid | |
| flowchart TD | |
| C(next-custom-transforms) --> A(napi) | |
| C(next-custom-transforms) --> B(wasm) | |
| D(next-core) --> A(napi) | |
| E(next-build) --> A(napi) | |
| F(next-api) --> A(napi) | |
| C(next-custom-transforms) --> D | |
| D(next-core) --> F(next-api) | |
| D(next-core) --> E(next-build) | |
| ``` | |
| - `next-custom-transforms`: provides next-swc specific SWC transform visitors. Turbopack, and the plain next-swc bidnings (`transform`) use these transforms. Since this is a bottom package can be imported in any place (turbopack / next-swc / wasm), it is important package do not contain specific dependencies. For example, using Turbopack's VC in this package will cause build failures to wasm bindings. | |
| - `next-core`: Implements Turbopack features for the next.js core functionality. This is also the place where Turbopack-specific transform providers (implementing `CustomTransformer`) lives, which wraps swc's transformer in the `next-custom-transforms`. | |
| - `next-api`: Binding interface to the next.js provides a proper next.js functionality using `next-core`. | |
| - `napi` / `wasm`: The actual binding interfaces, napi for the node.js and wasm for the wasm. Note wasm bindings cannot import packages using turbopack's feature. | |
| #### To add new swc transforms | |
| 1. Implements a new visitor in `next-custom-transforms`. It is highly encouraged to use `VisitMut` instead of `Fold` for the performance reasons. | |
| 2. Implements a new `CustomTransformer` under `crates/next-core/src/next_shared/transforms` to make Turbopack's ecma transform plugin, then adjust corresponding rules in `crates/next-core/src/(next_client|next_server)/context.rs`. | |