honojs · yusukebe · Dec 16, 2023 · Dec 13, 2023 · Dec 13, 2023 · Dec 13, 2023
diff --git a/.changeset/twelve-spiders-fail.md b/.changeset/twelve-spiders-fail.md
@@ -0,0 +1,5 @@
+---
+'@hono/react-renderer': patch
+---
+
+feat: introduce React Renderer
diff --git a/packages/react-renderer/README.md b/packages/react-renderer/README.md
@@ -0,0 +1,224 @@
+# React Renderer Middleware
+
+React Renderer Middleware allows for the easy creation of a renderer based on React for Hono.
+
+## Installation
+
+```txt
+npm i @hono/react-renderer react react-dom hono
+npm i -D @types/react @types/react-dom
+```
+
+## Settings
+
+`tsconfig.json`:
+
+```json
+{
+  "compilerOptions": {
+    "jsx": "react-jsx",
+    "jsxImportSource": "react"
+  }
+}
+```
+
+## Usage
+
+### Basic
+
+```tsx
+import { Hono } from 'hono'
+import { reactRenderer } from '@hono/react-renderer'
+
+const app = new Hono()
+
+app.get(
+  '*',
+  reactRenderer(({ children }) => {
+    return (
+      <html>
+        <body>
+          <h1>React + Hono</h1>
+          <div>{children}</div>
+        </body>
+      </html>
+    )
+  })
+)
+
+app.get('/', (c) => {
+  return c.render(<p>Welcome!</p>)
+})
+```
+
+### Extending `Props`
+
+You can define types of `Props`:
+
+```tsx
+declare module '@hono/react-renderer' {
+  interface Props {
+    title: string
+  }
+}
+```
+
+Then, you can use it in the `reactRenderer()` function and pass values as a second argument to `c.render()`:
+
+```tsx
+app.get(
+  '*',
+  reactRenderer(({ children, title }) => {
+    return (
+      <html>
+        <head>
+          <title>{title}</title>
+        </head>
+        <body>
+          <div>{children}</div>
+        </body>
+      </html>
+    )
+  })
+)
+
+app.get('/', (c) => {
+  return c.render(<p>Welcome!</p>, {
+    title: 'Top Page',
+  })
+})
+```
+
+### `useRequestContext()`
+
+You can get an instance of `Context` in a function component:
+
+```tsx
+const Component = () => {
+  const c = useRequestContext()
+  return <p>You access {c.req.url}</p>
+}
+
+app.get('/', (c) => {
+  return c.render(<Component />)
+})
+```
+
+## Options
+
+### `docType`
+
+If you set it `true`, `DOCTYPE` will be added:
+
+```tsx
+app.get(
+  '*',
+  reactRenderer(
+    ({ children }) => {
+      return (
+        <html>
+          <body>
+            <div>{children}</div>
+          </body>
+        </html>
+      )
+    },
+    {
+      docType: true,
+    }
+  )
+)
+```
+
+The HTML is the following:
+
+```html
+<!DOCTYPE html>
+<html>
+  <body>
+    <div><p>Welcome!</p></div>
+  </body>
+</html>
+```
+
+You can specify the `docType` as you like.
+
+```tsx
+app.get(
+  '*',
+  reactRenderer(
+    ({ children }) => {
+      return (
+        <html>
+          <body>
+            <div>{children}</div>
+          </body>
+        </html>
+      )
+    },
+    {
+      docType:
+        '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">',
+    }
+  )
+)
+```
+
+### `stream`
+
+It enables returning a streaming response. You can use a `Suspense` with it:
+
+```tsx
+import { reactRenderer } from '@hono/react-renderer'
+import { Suspense } from 'react'
+
+app.get(
+  '*',
+  reactRenderer(
+    ({ children }) => {
+      return (
+        <html>
+          <body>
+            <div>{children}</div>
+          </body>
+        </html>
+      )
+    },
+    {
+      stream: true,
+    }
+  )
+)
+
+let done = false
+
+const Component = () => {
+  if (done) {
+    return <p>Done!</p>
+  }
+  throw new Promise((resolve) => {
+    done = true
+    setTimeout(resolve, 1000)
+  })
+}
+
+app.get('/', (c) => {
+  return c.render(
+    <Suspense fallback='loading...'>
+      <Component />
+    </Suspense>
+  )
+})
+```
+
+## Limitation
+
+A streaming feature is not available on Vite or Vitest.
+
+## Author
+
+Yusuke Wada <https://github.com/yusukebe>
+
+## License
+
+MIT
diff --git a/packages/react-renderer/package.json b/packages/react-renderer/package.json
@@ -0,0 +1,49 @@
+{
+  "name": "@hono/react-renderer",
+  "version": "0.0.0",
+  "description": "React Renderer Middleware for Hono",
+  "type": "module",
+  "main": "dist/index.js",
+  "module": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "test": "vitest --run",
+    "build": "tsup ./src/index.ts --external hono,react,react-dom --format esm,cjs --dts",
+    "publint": "publint"
+  },
+  "exports": {
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js",
+      "require": "./dist/index.cjs"
+    }
+  },
+  "license": "MIT",
+  "publishConfig": {
+    "registry": "https://registry.npmjs.org",
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/honojs/middleware.git"
+  },
+  "homepage": "https://github.com/honojs/middleware",
+  "peerDependencies": {
+    "hono": "*"
+  },
+  "devDependencies": {
+    "@types/react": "^18",
+    "@types/react-dom": "^18.2.17",
+    "hono": "^3.11.7",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "tsup": "^8.0.1",
+    "vitest": "^1.0.4"
+  },
+  "engines": {
+    "node": ">=18"
+  }
+}
diff --git a/packages/react-renderer/src/index.ts b/packages/react-renderer/src/index.ts
@@ -0,0 +1,9 @@
+export * from './react-renderer'
+
+export type Props = {}
+
+declare module 'hono' {
+  interface ContextRenderer {
+    (children: React.ReactElement, props?: Props): Response | Promise<Response>
+  }
+}
diff --git a/packages/react-renderer/src/react-renderer.ts b/packages/react-renderer/src/react-renderer.ts
@@ -0,0 +1,68 @@
+import type { Context } from 'hono'
+import type { Env, MiddlewareHandler } from 'hono/types'
+import React from 'react'
+import { renderToString, renderToReadableStream } from 'react-dom/server'
+import type { Props } from '.'
+
+type RendererOptions = {
+  docType?: boolean | string
+  stream?: boolean | Record<string, string>
+}
+
+type BaseProps = {
+  c: Context
+  children: React.ReactElement
+}
+
+const RequestContext = React.createContext<Context | null>(null)
+
+const createRenderer =
+  (c: Context, component?: React.FC<Props & BaseProps>, options?: RendererOptions) =>
+  async (children: React.ReactElement, props?: Props) => {
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    const node = component ? component({ children, c, ...props }) : children
+
+    if (options?.stream) {
+      const stream = await renderToReadableStream(
+        React.createElement(RequestContext.Provider, { value: c }, node)
+      )
+      return c.body(stream, {
+        headers:
+          options.stream === true
+            ? {
+                'Transfer-Encoding': 'chunked',
+                'Content-Type': 'text/html; charset=UTF-8',
+              }
+            : options.stream,
+      })
+    } else {
+      const docType =
+        typeof options?.docType === 'string'
+          ? options.docType
+          : options?.docType === true
+          ? '<!DOCTYPE html>'
+          : ''
+      const body =
+        docType + renderToString(React.createElement(RequestContext.Provider, { value: c }, node))
+      return c.html(body)
+    }
+  }
+
+export const reactRenderer = (
+  component?: React.FC<Props & BaseProps>,
+  options?: RendererOptions
+): MiddlewareHandler =>
+  function reactRenderer(c, next) {
+    c.setRenderer(createRenderer(c, component, options))
+    return next()
+  }
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export const useRequestContext = <E extends Env = any>(): Context<E> => {
+  const c = React.useContext(RequestContext)
+  if (!c) {
+    throw new Error('RequestContext is not provided.')
+  }
+  return c
+}