feat(build): warn dynamic import module with a static import alongside

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

@@ -111,7 +111,35 @@ export function buildReporterPlugin(config: ResolvedConfig): Plugin {
       compressedCount = 0
     },
 
-    renderChunk() {
+    renderChunk(code, chunk) {
+      for (const id of chunk.moduleIds) {
+        const module = this.getModuleInfo(id)
+        if (!module) continue
+        // When a dynamic importer shares a chunk with the imported module,
+        // warn that the dynamic imported module will not be moved to another chunk (#12850).
+        if (module.importers.length && module.dynamicImporters.length) {
+          // Filter out the intersection of dynamic importers and sibling modules in
+          // the same chunk. The intersecting dynamic importers' dynamic import is not
+          // expected to work. Note we're only detecting the direct ineffective
+          // dynamic import here.
+          if (
+            module.dynamicImporters.some((m) => chunk.moduleIds.includes(m))
+          ) {
+            this.warn(
+              `\n(!) ${
+                module.id
+              } is dynamically imported by ${module.dynamicImporters
+                .map((m) => m)
+                .join(', ')} but also statically imported by ${module.importers
+                .map((m) => m)
+                .join(
+                  ', ',
+                )}, dynamic import will not move module into another chunk.\n`,
+            )
+          }
+        }
+      }
+
       chunkCount++
       if (shouldLogInfo) {
         if (!tty) {

playground/dynamic-import/__tests__/dynamic-import.spec.ts

@@ -129,3 +129,22 @@ test('should work with load ../ and contain itself directory', async () => {
     true,
   )
 })
+
+test.runIf(isBuild)(
+  'should rollup warn when static and dynamic import a module in same chunk',
+  async () => {
+    const log = serverLogs.join('\n')
+    expect(log).toContain(
+      'dynamic import will not move module into another chunk',
+    )
+    expect(log).toMatch(
+      /\(!\).*\/dynamic-import\/files\/mxd\.js is dynamically imported by/,
+    )
+    expect(log).toMatch(
+      /\(!\).*\/dynamic-import\/files\/mxd\.json is dynamically imported by/,
+    )
+    expect(log).not.toMatch(
+      /\(!\).*\/dynamic-import\/nested\/shared\.js is dynamically imported by/,
+    )
+  },
+)