feat: add hmr support for compound components (#518)

Co-authored-by: Arnaud Barré <[email protected]>

Author: Newbie012

packages/common/refresh-runtime.js

@@ -545,6 +545,21 @@ function isLikelyComponentType(type) {
   }
 }
 
+function isCompoundComponent(type) {
+  if (!isPlainObject(type)) return false
+  for (const key in type) {
+    if (!isLikelyComponentType(type[key])) return false
+  }
+  return true
+}
+
+function isPlainObject(obj) {
+  return (
+    Object.prototype.toString.call(obj) === '[object Object]' &&
+    (obj.constructor === Object || obj.constructor === undefined)
+  )
+}
+
 /**
  * Plugin utils
  */
@@ -565,6 +580,13 @@ export function registerExportsForReactRefresh(filename, moduleExports) {
       // The register function has an identity check to not register twice the same component,
       // so this is safe to not used the same key here.
       register(exportValue, filename + ' export ' + key)
+    } else if (isCompoundComponent(exportValue)) {
+      for (const subKey in exportValue) {
+        register(
+          exportValue[subKey],
+          filename + ' export ' + key + '-' + subKey,
+        )
+      }
     }
   }
 }
@@ -618,6 +640,7 @@ export function validateRefreshBoundaryAndEnqueueUpdate(
     (key, value) => {
       hasExports = true
       if (isLikelyComponentType(value)) return true
+      if (isCompoundComponent(value)) return true
       return prevExports[key] === nextExports[key]
     },
   )

packages/plugin-react-oxc/CHANGELOG.md

@@ -2,6 +2,17 @@
 
 ## Unreleased
 
+### Add HMR support for compound components ([#518](https://github.com/vitejs/vite-plugin-react/pull/518))
+
+HMR now works for compound components like this:
+
+```tsx
+const Root = () => <div>Accordion Root</div>
+const Item = () => <div>Accordion Item</div>
+
+export const Accordion = { Root, Item }
+```
+
 ### Return `Plugin[]` instead of `PluginOption[]`
 
 ## 0.2.3 (2025-06-16)

packages/plugin-react-swc/CHANGELOG.md

@@ -2,6 +2,17 @@
 
 ## Unreleased
 
+### Add HMR support for compound components ([#518](https://github.com/vitejs/vite-plugin-react/pull/518))
+
+HMR now works for compound components like this:
+
+```tsx
+const Root = () => <div>Accordion Root</div>
+const Item = () => <div>Accordion Item</div>
+
+export const Accordion = { Root, Item }
+```
+
 ### Return `Plugin[]` instead of `PluginOption[]`
 
 ## 3.10.2 (2025-06-10)

packages/plugin-react/CHANGELOG.md

@@ -2,6 +2,17 @@
 
 ## Unreleased
 
+### Add HMR support for compound components ([#518](https://github.com/vitejs/vite-plugin-react/pull/518))
+
+HMR now works for compound components like this:
+
+```tsx
+const Root = () => <div>Accordion Root</div>
+const Item = () => <div>Accordion Item</div>
+
+export const Accordion = { Root, Item }
+```
+
 ### Return `Plugin[]` instead of `PluginOption[]`
 
 The return type has changed from `react(): PluginOption[]` to more specialized type `react(): Plugin[]`. This allows for type-safe manipulation of plugins, for example:

playground/react/App.jsx

@@ -1,6 +1,7 @@
 import { useState } from 'react'
 import Button from 'jsx-entry'
 import Dummy from './components/Dummy?qs-should-not-break-plugin-react'
+import { Accordion } from './components/Accordion'
 import Parent from './hmr/parent'
 import { JsxImportRuntime } from './hmr/jsx-import-runtime'
 import { CountProvider } from './context/CountProvider'
@@ -38,6 +39,10 @@ function App() {
       </header>
 
       <Dummy />
+      <Accordion.Root>
+        <Accordion.Item>First Item</Accordion.Item>
+        <Accordion.Item>Second Item</Accordion.Item>
+      </Accordion.Root>
       <Parent />
       <JsxImportRuntime />
       <Button>button</Button>

playground/react/__tests__/react.spec.ts

@@ -148,4 +148,19 @@ if (!isBuild) {
 
     expect(await page.textContent('#state-button')).toMatch('count is: 1')
   })
+
+  // #493
+  test('should hmr compound components', async () => {
+    await untilBrowserLogAfter(
+      () =>
+        editFile('components/Accordion.jsx', (code) =>
+          code.replace('Accordion Root', 'Accordion Root Updated'),
+        ),
+      ['[vite] hot updated: /components/Accordion.jsx'],
+    )
+
+    await expect
+      .poll(() => page.textContent('#accordion-root'))
+      .toMatch('Accordion Root Updated')
+  })
 }

playground/react/components/Accordion.jsx

@@ -0,0 +1,37 @@
+function Root({ children }) {
+  return (
+    <div
+      style={{
+        border: '1px solid #ccc',
+        borderRadius: '4px',
+        margin: '16px 0',
+      }}
+    >
+      <h3
+        id="accordion-root"
+        style={{ padding: '12px', margin: '0', backgroundColor: '#f5f5f5' }}
+      >
+        Accordion Root
+      </h3>
+      <div style={{ padding: '12px' }}>{children}</div>
+    </div>
+  )
+}
+
+function Item({ children }) {
+  return (
+    <div
+      style={{
+        padding: '8px 12px',
+        border: '1px solid #e0e0e0',
+        margin: '4px 0',
+        borderRadius: '2px',
+        backgroundColor: '#fafafa',
+      }}
+    >
+      {children}
+    </div>
+  )
+}
+
+export const Accordion = { Root, Item }