fix(ssr): replace __vite_ssr_identity__ with (0, ...) and inject ; between statements

package.json

@@ -28,6 +28,7 @@
     "test-build": "VITE_TEST_BUILD=1 vitest run -c vitest.config.e2e.ts",
     "test-unit": "vitest run",
     "test-docs": "pnpm run docs-build",
+    "bench": "vitest bench",
     "debug-serve": "VITE_DEBUG_SERVE=1 vitest run -c vitest.config.e2e.ts",
     "debug-build": "VITE_TEST_BUILD=1 VITE_PRESERVE_BUILD_ARTIFACTS=1 vitest run -c vitest.config.e2e.ts",
     "docs": "pnpm --filter=docs run docs",

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

@@ -0,0 +1,81 @@
+import fs from 'node:fs'
+import { bench } from 'vitest'
+import { ssrTransform } from '../ssrTransform'
+
+const ssrTransformSimple = async (code: string, url = '') =>
+  ssrTransform(code, null, url, code)
+const ssrTransformSimpleCode = async (code: string, url?: string) =>
+  (await ssrTransformSimple(code, url))?.code
+
+bench(
+  'basic',
+  async () => {
+    await ssrTransformSimpleCode(`
+import { f } from './f'
+
+let x = 0;
+
+x
+f()
+
+if (1)
+  x
+f()
+
+if (1)
+  x
+else
+  x
+f()
+
+
+let y = x
+f()
+
+x /*;;*/ /*;;*/
+f()
+
+function z() {
+  x
+  f()
+
+  if (1) {
+    x
+    f()
+  }
+}
+
+let a = {}
+f()
+
+let b = () => {}
+f()
+
+function c() {
+}
+f()
+
+class D {
+}
+f()
+
+{
+  x
+}
+f()
+`)
+  },
+  { time: 5000 },
+)
+
+const file =
+  'packages/vite/src/node/ssr/__tests__/node_modules/.cache/_chunk-YE4AM67Y.js'
+const js = fs.readFileSync(file, 'utf-8')
+
+bench(
+  'large',
+  async () => {
+    await ssrTransformSimpleCode(js)
+  },
+  { time: 5000 },
+)