From cdf9d4f9d7873566d85e3c45f7de4d154a766dcd Mon Sep 17 00:00:00 2001
From: xingxiuyi <xingxiuyi@hreeinfo.com>
Date: Thu, 1 Jul 2021 08:25:37 +0800
Subject: [PATCH] fix: Avoid importing in source that __vitePreload has
 declared (close #4016) (#4041)

Co-authored-by: patak <matias.capeletto@gmail.com>
---
 packages/vite/src/node/plugins/importAnalysisBuild.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/vite/src/node/plugins/importAnalysisBuild.ts b/packages/vite/src/node/plugins/importAnalysisBuild.ts
index 52faaa095ba120..98aecac489f838 100644
--- a/packages/vite/src/node/plugins/importAnalysisBuild.ts
+++ b/packages/vite/src/node/plugins/importAnalysisBuild.ts
@@ -161,7 +161,11 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
         }
       }
 
-      if (needPreloadHelper && !ssr) {
+      if (
+        needPreloadHelper &&
+        !ssr &&
+        !source.includes(`const ${preloadMethod} =`)
+      ) {
         str().prepend(`import { ${preloadMethod} } from "${preloadHelperId}";`)
       }