fix: fix HMR propagation when imports not analyzed

packages/playground/hmr/__tests__/hmr.spec.ts

@@ -160,4 +160,33 @@ if (!isBuild) {
     expect(textprev).not.toMatch('direct')
     expect(textpost).not.toMatch('direct')
   })
+
+  test('not loaded dynamic import', async () => {
+    await page.goto(viteTestUrl + '/dynamic-import/index.html')
+
+    let btn = await page.$('button')
+    expect(await btn.textContent()).toBe('Counter 0')
+    await btn.click()
+    expect(await btn.textContent()).toBe('Counter 1')
+
+    // Modifying `index.ts` triggers a page reload, as expected
+    editFile('dynamic-import/index.ts', (code) => code)
+    await page.waitForNavigation()
+    btn = await page.$('button')
+    expect(await btn.textContent()).toBe('Counter 0')
+
+    await btn.click()
+    expect(await btn.textContent()).toBe('Counter 1')
+
+    // Modifying a dynamic import that has not been loaded has no effect (doesn't trigger a page reload)
+    editFile('dynamic-import/dep.ts', (code) => code)
+    try {
+      await page.waitForNavigation({ timeout: 1000 })
+    } catch (err) {
+      const errMsg = 'page.waitForNavigation: Timeout 1000ms exceeded.'
+      expect(err.message.slice(0, errMsg.length)).toBe(errMsg)
+    }
+    btn = await page.$('button')
+    expect(await btn.textContent()).toBe('Counter 1')
+  })
 }

packages/playground/hmr/dynamic-import/dep.ts

@@ -0,0 +1 @@
+// This file is never loaded

packages/playground/hmr/dynamic-import/index.html

@@ -0,0 +1,2 @@
+<button>Counter 0</button>
+<script type="module" src="./index.ts"></script>

packages/playground/hmr/dynamic-import/index.ts

@@ -0,0 +1,12 @@
+const btn = document.querySelector('button')
+let count = 0
+const update = () => {
+  btn.textContent = `Counter ${count}`
+}
+btn.onclick = () => {
+  count++
+  update()
+}
+function neverCalled() {
+  import('./dep')
+}

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

@@ -112,7 +112,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
     tryIndex: false,
     extensions: []
   })
-  let server: ViteDevServer
+  let server: ViteDevServer | null = null
 
   return {
     name: 'vite:import-analysis',
@@ -122,6 +122,10 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
     },
 
     async transform(source, importer, options) {
+      if (server === null) {
+        return null
+      }
+
       const ssr = options?.ssr === true
       const prettyImporter = prettifyUrl(importer, root)
 
@@ -159,7 +163,13 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
         )
       }
 
+      const { moduleGraph } = server
+      // since we are already in the transform phase of the importer, it must
+      // have been loaded so its entry is guaranteed in the module graph.
+      const importerModule = moduleGraph.getModuleById(importer)!
+
       if (!imports.length) {
+        importerModule.isSelfAccepting = false
         isDebug &&
           debug(
             `${timeFrom(start)} ${colors.dim(`[no imports] ${prettyImporter}`)}`
@@ -173,11 +183,6 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
       let needQueryInjectHelper = false
       let s: MagicString | undefined
       const str = () => s || (s = new MagicString(source))
-      // vite-only server context
-      const { moduleGraph } = server
-      // since we are already in the transform phase of the importer, it must
-      // have been loaded so its entry is guaranteed in the module graph.
-      const importerModule = moduleGraph.getModuleById(importer)!
       const importedUrls = new Set<string>()
       const staticImportedUrls = new Set<string>()
       const acceptedUrls = new Set<{
@@ -198,7 +203,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
 
         let importerFile = importer
         if (moduleListContains(config.optimizeDeps?.exclude, url)) {
-          const optimizedDeps = server._optimizedDeps
+          const optimizedDeps = server!._optimizedDeps
           if (optimizedDeps) {
             await optimizedDeps.scanProcessing
 
@@ -659,7 +664,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
             NULL_BYTE_PLACEHOLDER,
             '\0'
           )
-          transformRequest(url, server, { ssr }).catch((e) => {
+          transformRequest(url, server!, { ssr }).catch((e) => {
             if (e?.code === ERR_OUTDATED_OPTIMIZED_DEP) {
               // This are expected errors
               return

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

@@ -225,6 +225,12 @@ function propagateUpdate(
   }>,
   currentChain: ModuleNode[] = [node]
 ): boolean /* hasDeadEnd */ {
+  // if the imports of `node` have not been analyzed, then `node` has not
+  // been loaded in the browser and we should stop propagation.
+  if (node.id && node.isSelfAccepting === null) {
+    return false
+  }
+
   if (node.isSelfAccepting) {
     boundaries.add({
       boundary: node,

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

@@ -27,7 +27,7 @@ export class ModuleNode {
   importers = new Set<ModuleNode>()
   importedModules = new Set<ModuleNode>()
   acceptedHmrDeps = new Set<ModuleNode>()
-  isSelfAccepting = false
+  isSelfAccepting: boolean | null = null
   transformResult: TransformResult | null = null
   ssrTransformResult: TransformResult | null = null
   ssrModule: Record<string, any> | null = null