test(vitest): ignore SFC spec blocks during tests (ignore ?vue&type=spec requests)

Author: KaiShoya

vitest.config.ts

@@ -2,6 +2,32 @@ import { defineConfig } from 'vitest/config'
 import { fileURLToPath } from 'node:url'
 import AutoImport from 'unplugin-auto-import/vite'
 import vue from '@vitejs/plugin-vue'
+import type { Plugin } from 'vite'
+
+// During tests, SFC custom blocks with `lang="md"` (e.g. <spec lang="md">)
+// may be requested as `?vue&type=spec&index=0&lang.md` and Vite/Rollup can
+// attempt to parse them as JS modules, causing parse errors. Add a small
+// Vite plugin for the test config that returns a no-op module for those ids.
+function ignoreVueSpecBlocks() {
+  return {
+    name: 'ignore-vue-spec-blocks' as const,
+    enforce: 'pre',
+    transform(code: string, id: string) {
+      try {
+        if (id && /[?&]type=spec(?:&|$)/.test(id)) {
+          // return an empty module so Rollup/Vite won't try to parse markdown
+          return {
+            code: 'export default {}',
+            map: { mappings: '' }
+          }
+        }
+      } catch {
+        // noop
+      }
+      return null
+    }
+  } as Plugin
+}
 
 export default defineConfig({
   test: {
@@ -21,6 +47,7 @@ export default defineConfig({
       imports: ['vue', 'vue-i18n'],
       dts: false
     }),
+    ignoreVueSpecBlocks(),
     vue()
   ]
 })