fix: handle addWatchFile in load hooks

packages/vite/src/node/server/pluginContainer.ts

@@ -82,7 +82,7 @@ import { FS_PREFIX } from '../constants'
 import type { ResolvedConfig } from '../config'
 import { createPluginHookUtils, getHookHandler } from '../plugins'
 import { buildErrorMessage } from './middlewares/error'
-import type { ModuleGraph } from './moduleGraph'
+import type { ModuleGraph, ModuleNode } from './moduleGraph'
 
 const noop = () => {}
 
@@ -182,6 +182,11 @@ export async function createPluginContainer(
   // ---------------------------------------------------------------------------
 
   const watchFiles = new Set<string>()
+  // _addedFiles from the `load()` hook gets saved here so it can be reused in the `transform()` hook
+  const moduleNodeToLoadAddedImports = new WeakMap<
+    ModuleNode,
+    Set<string> | null
+  >()
 
   const minimalContext: MinimalPluginContext = {
     meta: {
@@ -273,6 +278,13 @@ export async function createPluginContainer(
     }
   }
 
+  function updateModuleLoadAddedImports(id: string, ctx: Context) {
+    const module = moduleGraph?.getModuleById(id)
+    if (module) {
+      moduleNodeToLoadAddedImports.set(module, ctx._addedImports)
+    }
+  }
+
   // we should create a new context for each async hook pipeline so that the
   // active plugin in that pipeline can be tracked in a concurrency-safe manner.
   // using a class to make creating new contexts more efficient
@@ -520,9 +532,9 @@ export async function createPluginContainer(
     sourcemapChain: NonNullable<SourceDescription['map']>[] = []
     combinedMap: SourceMap | { mappings: '' } | null = null
 
-    constructor(filename: string, code: string, inMap?: SourceMap | string) {
+    constructor(id: string, code: string, inMap?: SourceMap | string) {
       super()
-      this.filename = filename
+      this.filename = id
       this.originalCode = code
       if (inMap) {
         if (debugSourcemapCombine) {
@@ -531,6 +543,11 @@ export async function createPluginContainer(
         }
         this.sourcemapChain.push(inMap)
       }
+      // Inherit `_addedImports` from the `load()` hook
+      const node = moduleGraph?.getModuleById(id)
+      if (node) {
+        this._addedImports = moduleNodeToLoadAddedImports.get(node) ?? null
+      }
     }
 
     _getCombinedSourcemap() {
@@ -719,9 +736,11 @@ export async function createPluginContainer(
           if (isObject(result)) {
             updateModuleInfo(id, result)
           }
+          updateModuleLoadAddedImports(id, ctx)
           return result
         }
       }
+      updateModuleLoadAddedImports(id, ctx)
       return null
     },
 

playground/transform-plugin/__tests__/transform-plugin.spec.ts

@@ -1,9 +1,12 @@
 import { expect, test } from 'vitest'
 import { editFile, page, untilUpdated } from '~utils'
 
-test('should re-run transform when plugin-dep file is edited', async () => {
+test('should re-run transform when dependencies are edited', async () => {
   expect(await page.textContent('#transform-count')).toBe('1')
 
-  await editFile('plugin-dep.js', (str) => str)
+  editFile('plugin-dep.js', (str) => str)
   await untilUpdated(() => page.textContent('#transform-count'), '2')
+
+  editFile('plugin-dep-load.js', (str) => str)
+  await untilUpdated(() => page.textContent('#transform-count'), '3')
 })

playground/transform-plugin/plugin-dep-load.js

@@ -0,0 +1 @@
+// Empty file for detecting changes in tests

playground/transform-plugin/vite.config.js

@@ -1,12 +1,19 @@
 import { resolve } from 'node:path'
 import { defineConfig, normalizePath } from 'vite'
 
+const file = normalizePath(resolve(__dirname, 'index.js'))
 let transformCount = 1
 
 const transformPlugin = {
   name: 'transform',
+  load(id) {
+    if (id === file) {
+      // Ensure `index.js` is reloaded if 'plugin-dep-load.js' is changed
+      this.addWatchFile('./plugin-dep-load.js')
+    }
+  },
   transform(code, id) {
-    if (id === normalizePath(resolve(__dirname, 'index.js'))) {
+    if (id === file) {
       // Ensure `index.js` is reevaluated if 'plugin-dep.js' is changed
       this.addWatchFile('./plugin-dep.js')