fix: importmap should insert before module preload link (#11492)

fi3ework · web-flow · commit 25c64d7ec206 · 2023-01-02T17:04:50.000+08:00
diff --git a/packages/vite/src/node/plugins/html.ts b/packages/vite/src/node/plugins/html.ts
@@ -50,6 +50,12 @@ const importMapRE =
   /[ \t]*<script[^>]*type\s*=\s*(?:"importmap"|'importmap'|importmap)[^>]*>.*?<\/script>/is
 const moduleScriptRE =
   /[ \t]*<script[^>]*type\s*=\s*(?:"module"|'module'|module)[^>]*>/i
+const modulePreloadLinkRE =
+  /[ \t]*<link[^>]*rel\s*=\s*(?:"modulepreload"|'modulepreload'|modulepreload)[\s\S]*?\/>/i
+const importMapAppendRE = new RegExp(
+  [moduleScriptRE, modulePreloadLinkRE].map((r) => r.source).join('|'),
+  'i',
+)
 
 export const isHTMLProxy = (id: string): boolean => htmlProxyRE.test(id)
 
@@ -891,17 +897,17 @@ export function preImportMapHook(
     const importMapIndex = html.match(importMapRE)?.index
     if (importMapIndex === undefined) return
 
-    const moduleScriptIndex = html.match(moduleScriptRE)?.index
-    if (moduleScriptIndex === undefined) return
+    const importMapAppendIndex = html.match(importMapAppendRE)?.index
+    if (importMapAppendIndex === undefined) return
 
-    if (moduleScriptIndex < importMapIndex) {
+    if (importMapAppendIndex < importMapIndex) {
       const relativeHtml = normalizePath(
         path.relative(config.root, ctx.filename),
       )
       config.logger.warnOnce(
         colors.yellow(
           colors.bold(
-            `(!) <script type="importmap"> should come before <script type="module"> in /${relativeHtml}`,
+            `(!) <script type="importmap"> should come before <script type="module"> and <link rel="modulepreload"> in /${relativeHtml}`,
           ),
         ),
       )
@@ -910,19 +916,23 @@ export function preImportMapHook(
 }
 
 /**
- * Move importmap before the first module script
+ * Move importmap before the first module script and modulepreload link
  */
 export function postImportMapHook(): IndexHtmlTransformHook {
   return (html) => {
-    if (!moduleScriptRE.test(html)) return
+    if (!importMapAppendRE.test(html)) return
 
     let importMap: string | undefined
     html = html.replace(importMapRE, (match) => {
       importMap = match
       return ''
     })
+
     if (importMap) {
-      html = html.replace(moduleScriptRE, (match) => `${importMap}\n${match}`)
+      html = html.replace(
+        importMapAppendRE,
+        (match) => `${importMap}\n${match}`,
+      )
     }
 
     return html
diff --git a/playground/html/__tests__/html.spec.ts b/playground/html/__tests__/html.spec.ts
@@ -251,12 +251,6 @@ describe.runIf(isServe)('invalid', () => {
   })
 })
 
-test('importmap', () => {
-  expect(browserLogs).not.toContain(
-    'An import map is added after module script load was triggered.',
-  )
-})
-
 describe('Valid HTML', () => {
   test('valid HTML is parsed', async () => {
     await page.goto(viteTestUrl + '/valid.html')
@@ -267,3 +261,16 @@ describe('Valid HTML', () => {
     expect(await getColor('#duplicated-attrs')).toBe('green')
   })
 })
+
+describe('importmap', () => {
+  beforeAll(async () => {
+    await page.goto(viteTestUrl + '/importmapOrder.html')
+  })
+
+  // Should put this test at the end to get all browser logs above
+  test('importmap should be prepended', async () => {
+    expect(browserLogs).not.toContain(
+      'An import map is added after module script load was triggered.',
+    )
+  })
+})
diff --git a/playground/html/importmapOrder.html b/playground/html/importmapOrder.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <script type="importmap">
+      {
+        "imports": {
+          "some-pkg": "url-of-pkg"
+        }
+      }
+    </script>
+    <link rel="modulepreload" href="url-of-pkg" />
+    <script type="module" src="/main.js"></script>
+  </head>
+</html>
diff --git a/playground/html/vite.config.js b/playground/html/vite.config.js
@@ -28,6 +28,7 @@ module.exports = {
         ),
         linkProps: resolve(__dirname, 'link-props/index.html'),
         valid: resolve(__dirname, 'valid.html'),
+        importmapOrder: resolve(__dirname, 'importmapOrder.html'),
       },
     },
   },
@@ -168,7 +169,9 @@ ${
     },
     {
       name: 'head-prepend-importmap',
-      transformIndexHtml() {
+      transformIndexHtml(_, ctx) {
+        if (ctx.path.includes('importmapOrder')) return
+
         return [
           {
             tag: 'script',
