fix(legacy): code was running twice on Chrome 63

vitejs · Feb 2, 2023 · 5ac8417 · 5ac8417
1 parent b451858
commit 5ac8417
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Showing 2 changed files with 5 additions and 4 deletions.
diff --git a/packages/plugin-legacy/src/index.ts b/packages/plugin-legacy/src/index.ts
@@ -28,9 +28,9 @@ import type { Options } from './types'
 import {
   detectModernBrowserCode,
   dynamicFallbackInlineCode,
-  forceDynamicImportUsage,
   legacyEntryId,
   legacyPolyfillId,
+  modernChunkLegacyGuard,
   safari10NoModuleFix,
   systemJSInlineCode,
 } from './snippets'
@@ -362,7 +362,8 @@ function viteLegacyPlugin(options: Options = {}): Plugin[] {
         const ms = new MagicString(raw)
 
         if (genLegacy && chunk.isEntry) {
-          ms.prepend(forceDynamicImportUsage)
+          // append this code to avoid modern chunks running on legacy targeted browsers
+          ms.prepend(modernChunkLegacyGuard)
         }
 
         if (raw.includes(legacyEnvVarMarker)) {

diff --git a/packages/plugin-legacy/src/snippets.ts b/packages/plugin-legacy/src/snippets.ts
@@ -10,6 +10,6 @@ const detectModernBrowserVarName = '__vite_is_modern_browser'
 export const detectModernBrowserDetector =
   'import.meta.url;import("_").catch(()=>1);'
 export const detectModernBrowserCode = `${detectModernBrowserDetector}window.${detectModernBrowserVarName}=true;`
-export const dynamicFallbackInlineCode = `!function(){if(window.${detectModernBrowserVarName})return;console.warn("vite: loading legacy build because dynamic import or import.meta.url is unsupported, syntax error above should be ignored");var e=document.getElementById("${legacyPolyfillId}"),n=document.createElement("script");n.src=e.src,n.onload=function(){${systemJSInlineCode}},document.body.appendChild(n)}();`
+export const dynamicFallbackInlineCode = `!function(){if(window.${detectModernBrowserVarName})return;console.warn("vite: loading legacy build because dynamic import or import.meta.url is unsupported, syntax error above and the same error below should be ignored");var e=document.getElementById("${legacyPolyfillId}"),n=document.createElement("script");n.src=e.src,n.onload=function(){${systemJSInlineCode}},document.body.appendChild(n)}();`
 
-export const forceDynamicImportUsage = `export function __vite_legacy_guard(){import('data:text/javascript,')};`
+export const modernChunkLegacyGuard = `export function __vite_legacy_guard(){${detectModernBrowserDetector}};`