fix(hmr): trigger prune event when import is removed from non hmr module

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

@@ -835,7 +835,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
           isSelfAccepting,
           staticImportedUrls,
         )
-        if (hasHMR && prunedImports) {
+        if (prunedImports) {
           handlePrunedModules(prunedImports, environment)
         }
       }

playground/hmr/__tests__/hmr.spec.ts

@@ -997,6 +997,15 @@ if (!isBuild) {
       .toMatch('parent:child')
   })
 
+  test('deleting import from non-self-accepting module can trigger prune event', async () => {
+    await page.goto(viteTestUrl)
+    await expect.poll(() => page.textContent('.prune')).toMatch('init')
+    editFile('prune/dep1.js', (code) =>
+      code.replace(`import './dep2.js'`, `// import './dep2.js'`),
+    )
+    await expect.poll(() => page.textContent('.prune')).toMatch('dep2-pruned')
+  })
+
   test('import.meta.hot?.accept', async () => {
     await page.goto(viteTestUrl)
 

playground/hmr/hmr.ts

@@ -7,6 +7,7 @@ import './file-delete-restore'
 import './optional-chaining/parent'
 import './intermediate-file-delete'
 import './circular'
+import './prune'
 import logo from './logo.svg'
 import logoNoInline from './logo-no-inline.svg'
 import { msg as softInvalidationMsg } from './soft-invalidation'

playground/hmr/index.html

@@ -45,3 +45,4 @@
 <img id="logo" />
 <img id="logo-no-inline" />
 <div class="circular"></div>
+<div class="prune">prune/init</div>

playground/hmr/prune/dep1.js

@@ -0,0 +1,8 @@
+import './dep2.js'
+
+// TODO: https://github.com/vitejs/vite/issues/20781
+// currently we need one more `import` in this module
+// to trigger prune for depending module `dep2.js` since
+// the prune event logic is skipped when `es-module-lexer`
+// detects `imports.length === 0`
+import './dep2-other.js'

playground/hmr/prune/dep2.js

@@ -0,0 +1,5 @@
+if (import.meta.hot) {
+  import.meta.hot.prune(() => {
+    document.querySelector('.prune').textContent = 'prune/dep2-pruned'
+  })
+}

playground/hmr/prune/index.js

@@ -0,0 +1,5 @@
+import './dep1.js'
+
+if (import.meta.hot) {
+  import.meta.hot.accept(() => {})
+}