fix: make addWatchFile() work (fix #7024) (#9723)

Co-authored-by: Matt Jones <mattjones701@gmail.com>

Author: zqianem

packages/vite/src/node/plugins/importAnalysis.ts

@@ -231,7 +231,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
         throwOutdatedRequest(importer)
       }
 
-      if (!imports.length) {
+      if (!imports.length && !(this as any)._addedImports) {
         importerModule.isSelfAccepting = false
         isDebug &&
           debug(
@@ -263,7 +263,8 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
 
       const normalizeUrl = async (
         url: string,
-        pos: number
+        pos: number,
+        forceSkipImportAnalysis: boolean = false
       ): Promise<[string, string]> => {
         url = stripBase(url, base)
 
@@ -364,7 +365,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
             const depModule = await moduleGraph.ensureEntryFromUrl(
               unwrapId(url),
               ssr,
-              canSkipImportAnalysis(url)
+              canSkipImportAnalysis(url) || forceSkipImportAnalysis
             )
             if (depModule.lastHMRTimestamp > 0) {
               url = injectQuery(url, `t=${depModule.lastHMRTimestamp}`)
@@ -667,7 +668,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
         if (pluginImports) {
           ;(
             await Promise.all(
-              [...pluginImports].map((id) => normalizeUrl(id, 0))
+              [...pluginImports].map((id) => normalizeUrl(id, 0, true))
             )
           ).forEach(([url]) => importedUrls.add(url))
         }

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

@@ -0,0 +1,9 @@
+import { expect, test } from 'vitest'
+import { editFile, page, untilUpdated } from '~utils'
+
+test('should re-run transform when plugin-dep file is edited', async () => {
+  expect(await page.textContent('#transform-count')).toBe('1')
+
+  await editFile('plugin-dep.js', (str) => str)
+  await untilUpdated(() => page.textContent('#transform-count'), '2')
+})

playground/transform-plugin/index.html

@@ -0,0 +1,3 @@
+<div id="transform-count"></div>
+
+<script type="module" src="./index.js"></script>

playground/transform-plugin/index.js

@@ -0,0 +1,2 @@
+// 'TRANSFORM_COUNT' is injected by the transform plugin
+document.getElementById('transform-count').innerHTML = TRANSFORM_COUNT

playground/transform-plugin/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "test-transform-plugin",
+  "private": true,
+  "version": "0.0.0",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "debug": "node --inspect-brk ../../vite/bin/vite",
+    "serve": "vite preview"
+  }
+}

playground/transform-plugin/plugin-dep.js

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

playground/transform-plugin/vite.config.js

@@ -0,0 +1,25 @@
+const { resolve } = require('node:path')
+const { normalizePath } = require('vite')
+
+let transformCount = 1
+
+const transformPlugin = {
+  name: 'transform',
+  transform(code, id) {
+    if (id === normalizePath(resolve(__dirname, 'index.js'))) {
+      // Ensure `index.js` is reevaluated if 'plugin-dep.js' is changed
+      this.addWatchFile('./plugin-dep.js')
+
+      return `
+        // Inject TRANSFORM_COUNT
+        let TRANSFORM_COUNT = ${transformCount++};
+
+        ${code}
+      `
+    }
+  }
+}
+
+module.exports = {
+  plugins: [transformPlugin]
+}