feat: ssrTransform support import assertion by default (#14202)

Co-authored-by: bluwy <bjornlu.dev@gmail.com>

packages/vite/LICENSE.md

@@ -566,6 +566,13 @@ Repository: https://github.com/acornjs/acorn.git
 
 ---------------------------------------
 
+## acorn-import-assertions
+License: MIT
+By: Sven Sauleau
+Repository: https://github.com/xtuc/acorn-import-assertions
+
+---------------------------------------
+
 ## acorn-walk
 License: MIT
 By: Marijn Haverbeke, Ingvar Stepanyan, Adrian Heine

packages/vite/package.json

@@ -92,6 +92,7 @@
     "@types/escape-html": "^1.0.2",
     "@types/pnpapi": "^0.0.2",
     "acorn": "^8.10.0",
+    "acorn-import-assertions": "^1.9.0",
     "acorn-walk": "^8.2.0",
     "cac": "^6.7.14",
     "chokidar": "^3.5.3",

packages/vite/src/node/server/pluginContainer.ts

@@ -59,6 +59,8 @@ import type {
 import * as acorn from 'acorn'
 import type { RawSourceMap } from '@ampproject/remapping'
 import { TraceMap, originalPositionFor } from '@jridgewell/trace-mapping'
+// @ts-expect-error untyped
+import { importAssertions } from 'acorn-import-assertions'
 import MagicString from 'magic-string'
 import type { FSWatcher } from 'chokidar'
 import colors from 'picocolors'
@@ -150,7 +152,7 @@ type PluginContext = Omit<
   | 'moduleIds'
 >
 
-export let parser = acorn.Parser
+export let parser = acorn.Parser.extend(importAssertions)
 
 export async function createPluginContainer(
   config: ResolvedConfig,
@@ -628,6 +630,7 @@ export async function createPluginContainer(
       }
       if (options.acornInjectPlugins) {
         parser = acorn.Parser.extend(
+          importAssertions,
           ...(arraify(options.acornInjectPlugins) as any),
         )
       }

packages/vite/src/node/ssr/__tests__/ssrTransform.spec.ts

@@ -932,3 +932,17 @@ const Baz = class extends Foo {}
     "
   `)
 })
+
+test('import assertion attribute', async () => {
+  expect(
+    await ssrTransformSimpleCode(`
+  import * as foo from './foo.json' assert { type: 'json' };
+  import('./bar.json', { assert: { type: 'json' } });
+  `),
+  ).toMatchInlineSnapshot(`
+  "const __vite_ssr_import_0__ = await __vite_ssr_import__(\\"./foo.json\\");
+  
+    
+    __vite_ssr_dynamic_import__('./bar.json', { assert: { type: 'json' } });
+    "`)
+})