fix: perserve async generator function invocation

README.md

@@ -169,22 +169,26 @@ export default {
 
 ## Content Security Policy
 
-The legacy plugin requires inline scripts for [Safari 10.1 `nomodule` fix](https://gist.github.com/samthor/64b114e4a4f539915a95b91ffd340acc), SystemJS initialization, and dynamic import fallback. If you have a strict CSP policy requirement, you will need to [add the corresponding hashes to your `script-src` list](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/script-src#unsafe_inline_script):
+The legacy plugin requires inline scripts for [Safari 10.1 `nomodule` fix](https://gist.github.com/samthor/64b114e4a4f539915a95b91ffd340acc), SystemJS initialization, and dynamic import fallback. If you have a strict CSP policy requirement, you will need to [add the corresponding hashes to your `script-src` list](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/script-src#unsafe_inline_script).
+
+The hash values (without the `sha256-` prefix) can be retrieved via:
+
+```js
+import { cspHashes } from 'vite-plugin-legacy-swc'
+```
+
+The current values are:
 
 - `sha256-MS6/3FCg4WjP9gwgaBGwLpRCY6fZBgwmhVCdrPrNf3E=`
 - `sha256-tQjf8gvb2ROOMapIxFvFAYBeUJ0v1HCbOcSmDNXGtDo=`
-- `sha256-4y/gEB2/KIwZFTfNqwXJq4olzvmQ0S214m9jwKgNXoc=`
+- `sha256-VA8O2hAdooB288EpSTrGLl7z3QikbWU9wwoebO/QaYk=`
 - `sha256-+5XkZFazzJo8n0iOP4ti/cLCMUudTf//Mzkb7xNPXIc=`
 
 <!--
 Run `node --input-type=module -e "import {cspHashes} from 'vite-plugin-legacy-swc'; console.log(cspHashes.map(h => 'sha256-'+h))"` to retrieve the value.
 -->
 
-These values (without the `sha256-` prefix) can also be retrieved via
-
-```js
-import { cspHashes } from 'vite-plugin-legacy-swc'
-```
+Note that these values could change between minor versions. Thus, we recommend generating the CSP header from the exported `cspHashes` variable. If you copy the values manually, then you should pin the minor version using `~`.
 
 When using the `regenerator-runtime` polyfill, it will attempt to use the `globalThis` object to register itself. If `globalThis` is not available (it is [fairly new](https://caniuse.com/?search=globalThis) and not widely supported, including IE 11), it attempts to perform dynamic `Function(...)` call which violates the CSP. To avoid dynamic `eval` in the absence of `globalThis` consider adding `core-js/proposals/global-this` to `additionalLegacyPolyfills` to define it.
 

src/snippets.ts

@@ -7,9 +7,8 @@ export const legacyEntryId = 'vite-legacy-entry'
 export const systemJSInlineCode = `System.import(document.getElementById('${legacyEntryId}').getAttribute('data-src'))`
 
 const detectModernBrowserVarName = '__vite_is_modern_browser'
-export const detectModernBrowserDetector
-  = 'import.meta.url;import("_").catch(()=>1);async function* g(){};'
-export const detectModernBrowserCode = `${detectModernBrowserDetector}if(location.protocol!="file:"){window.${detectModernBrowserVarName}=true}`
+export const detectModernBrowserDetector = `import.meta.url;import("_").catch(()=>1);(async function*(){})().next()`
+export const detectModernBrowserCode = `${detectModernBrowserDetector};if(location.protocol!="file:"){window.${detectModernBrowserVarName}=true}`
 export const dynamicFallbackInlineCode = `!function(){if(window.${detectModernBrowserVarName})return;console.warn("vite: loading legacy chunks, syntax error above and the same error below should be ignored");var e=document.getElementById("${legacyPolyfillId}"),n=document.createElement("script");n.src=e.src,n.onload=function(){${systemJSInlineCode}},document.body.appendChild(n)}();`
 
 export const modernChunkLegacyGuard = `export function __vite_legacy_guard(){${detectModernBrowserDetector}};`

tests/snippets.spec.ts

@@ -1,15 +1,21 @@
 import type { ecmaVersion } from 'acorn'
 import { parse } from 'acorn'
-import { expect, test } from 'vitest'
-import { detectModernBrowserDetector } from '../src/snippets'
+import { describe, expect, test } from 'vitest'
+import {
+  detectModernBrowserCode,
+  detectModernBrowserDetector,
+  dynamicFallbackInlineCode,
+  safari10NoModuleFix,
+  systemJSInlineCode,
+} from '../src/snippets'
 
 const shouldFailVersions: ecmaVersion[] = []
 for (let v = 2015; v <= 2019; v++) {
   shouldFailVersions.push(v as ecmaVersion)
 }
 
-const shouldPassVersions: acorn.ecmaVersion[] = []
-for (let v = 2020; v <= 2022; v++) {
+const shouldPassVersions: ecmaVersion[] = []
+for (let v = 2020; v <= 2024; v++) {
   shouldPassVersions.push(v as ecmaVersion)
 }
 
@@ -34,3 +40,23 @@ for (const version of shouldPassVersions) {
     }).not.toThrow()
   })
 }
+
+describe('snippets are valid', () => {
+  const codes = {
+    safari10NoModuleFix,
+    systemJSInlineCode,
+    detectModernBrowserCode,
+    dynamicFallbackInlineCode,
+  }
+
+  for (const [name, value] of Object.entries(codes)) {
+    test(`${name} is valid JS`, () => {
+      expect(() => {
+        parse(value, {
+          ecmaVersion: 'latest',
+          sourceType: 'module',
+        })
+      }).not.toThrow()
+    })
+  }
+})