# Solid Refresh
```bash
npm i -D solid-refresh
```
```bash
yarn add -D solid-refresh
```
```bash
pnpm add -D solid-refresh
```
This project aims to provide HMR for Solid for various bundlers. It comes with a babel plugin and a runtime. Over time I hope to add different bundlers. Today it supports:
* Vite (with option `bundler: "vite"`)
* Snowpack (with option `bundler: "esm"`)
* Webpack (for strict ESM, use option `bundler: "webpack5"`)
* Nollup
## Setup
### Vite
`solid-refresh` is already built into [`vite-plugin-solid`](https://github.com/solidjs/vite-plugin-solid).
### Webpack & Rspack
You can read the following guides first, respectively:
* [Webpack](https://webpack.js.org/guides/hot-module-replacement#enabling-hmr)
* [Rspack](https://www.rspack.dev/guide/dev-server.html#hmr)
* [Rspack SolidJS guide](https://www.rspack.dev/guide/solid.html)
> **Note**
> Rspack has HMR already enabled by default. The guide only tells you how to disable it or run the dev server on a proxy server.
Requires the use of [`babel-loader`](https://www.npmjs.com/package/babel-loader). Add the following to `.babelrc`:
```json
{
"env": {
"development": {
"plugins": ["solid-refresh/babel"]
}
}
}
```
If you're using strict ESM a.k.a. `import.meta.webpackHot`:
```json
{
"env": {
"development": {
"plugins": [["solid-refresh/babel", {
"bundler": "webpack5" // or "rspack-esm"
}]]
}
}
}
```
In your webpack config, be sure to have the following options:
```js
devServer: {
liveReload: false,
hot: true,
}
```
### Nollup
Requires the use of [`@rollup/plugin-babel`](https://www.npmjs.com/package/@rollup/plugin-babel). Add the following to `.babelrc`:
```json
{
"env": {
"development": {
"plugins": ["solid-refresh/babel"]
}
}
}
```
### Snowpack
Requires the use of [`@snowpack/plugin-babel`](https://www.npmjs.com/package/@snowpack/plugin-babel). Add the following to `.babelrc`:
```json
{
"env": {
"development": {
"plugins": ["solid-refresh/babel", { "bundler": "esm" }]
}
}
}
```
### Other dev servers
* [`Parcel`](https://parceljs.org/)
* ParcelJS doesn't support [conditional exports](https://nodejs.org/api/packages.html#conditional-exports) yet, which makes ParcelJS load the production build of SolidJS instead of its development build. Solid Refresh requires the SolidJS development build to work.
* [`wmr`](https://wmr.dev/)
* SolidJS is yet to be supported or isn't clear yet. It will use the same config as Snowpack.
* [`rollup-plugin-hot`](https://github.com/rixo/rollup-plugin-hot)
* The library uses almost an ESM HMR-like API however it behaves the same way as Parcel. Supporting this library is still unclear.
* [`@web/dev-server`](https://modern-web.dev/docs/dev-server)
* The library supports HMR through their [HMR Plugin](https://modern-web.dev/docs/dev-server/plugins/hmr). The HMR interface is basically the same as Snowpack's.
### Development Environment
In any case, your build system needs to support conditional exports and have the `development` condition set.
> **Warning**
> In some standard HMR implementations, this may cause your app to reload the full page if the development environment isn't properly set!
## How it works
The babel plugin will transform components with matching Pascal-cased names (indicating that they are components). This detection is supported in variable declarations, function declarations and named exports:
```jsx
// This works
function Foo() {
return Hello Foo
;
}
// This also works
const Bar = () => Hello Bar
;
```
The components are wrapped and memoized. When the module receives an update, it replaces the old components from the old module with the new components.
## Automatic Render Cleanup
The plugin automatically handles cleanups for unhandled `render` and `hydrate` calls from `solid-js/web`.
You can disable this feature entirely through the option `"fixRender": false`.
## Pragma
On a per file basis, use comments at top of file to opt out(change moves up to parent):
```js
/* @refresh skip */
```
Or force reload:
```js
/* @refresh reload */
```
### `@refresh granular`
By default, components from the old module are replaced with the new ones from the replacement module, which might cause components that hasn't really changed to unmount abruptly.
Adding `@refresh granular` comment pragma in the file allows components to opt-in to granular replacement: If the component has changed *code-wise*, it will be replaced, otherwise, it will be retained, which allows unchanged ancestor components to preserve lifecycles.
## Limitations
* Preserving state: The default mode does not allow preserving state through module replacement. `@refresh granular` allows this partially.
* No HOC support.
## Custom `render`/`createContext`
You can define custom `render`/`createContext` calls by using the `imports` option
```js
{
"imports": [
{
// Only either "render" or "createContext"
"type": "render",
// Import identifier
"name": "render",
// Kind of import (named or default)
"kind": "named",
// Module source
"source": "my-solid-library"
}
],
}
```