Stop polyfilling structuredclone (#41823)

Peter Bengtsson · heiskr · web-flow · commit d4db0a43fe7c · 2023-09-20T16:16:28.000Z
Co-authored-by: Kevin Heis &lt;heiskr@users.noreply.github.com&gt;
diff --git a/src/content-render/unified/rewrite-asset-img-tags.js b/src/content-render/unified/rewrite-asset-img-tags.js
@@ -1,27 +1,5 @@
 import { visit, SKIP } from 'unist-util-visit'
 
-/**
- * `structuredClone` was added in Node 17 and onwards.
- * https://developer.mozilla.org/en-US/docs/Web/API/structuredClone#browser_compatibility
- *
- * At the time of writing, we use Node 18 in CI and in production, but
- * someone might be previewing locally with an older version so
- * let's make a quick polyfill.
- * We could add a specific (`js-core`) package for this polyfill, but it's
- * fortunately not necessary in this context because it's safe enough
- * clone by turning into a string and back again.
- */
-function structuredClonePolyfill(obj) {
-  if (typeof structuredClone !== 'undefined') {
-    return structuredClone(obj)
-  } else {
-    // Note, that this naive clone would turn Date objects into strings.
-    // So don't use this polyfill if certain values aren't primitives
-    // that JSON.parse can handle.
-    return JSON.parse(JSON.stringify(obj))
-  }
-}
-
 // This number must match a width we're willing to accept in a dynamic
 // asset URL.
 // (note this is exported for the sake of end-to-end tests' assertions)
@@ -52,7 +30,7 @@ export default function rewriteAssetImgTags() {
   return (tree) => {
     visit(tree, matcher, (node) => {
       if (node.properties.src.endsWith('.png')) {
-        const copyPNG = structuredClonePolyfill(node)
+        const copyPNG = structuredClone(node)
 
         const sourceWEBP = {
           type: 'element',
diff --git a/src/links/lib/update-internal-links.js b/src/links/lib/update-internal-links.js
@@ -20,17 +20,6 @@ import getRedirect, { splitPathByLanguage } from '#src/redirects/lib/get-redirec
 import nonEnterpriseDefaultVersion from '#src/versions/lib/non-enterprise-default-version.js'
 import { deprecated } from '#src/versions/lib/enterprise-server-releases.js'
 
-function objectClone(obj) {
-  try {
-    return structuredClone(obj)
-  } catch {
-    // Need to polyfill for Node 16 folks
-    // Using `yaml.load(yaml.dump(...))` is safe enough because this
-    // data itself came from the Yaml deserializing in frontmatter().
-    return yaml.load(yaml.dump(obj))
-  }
-}
-
 // That magical string that can be turned into th actual title when
 // we, at runtime, render out the links
 const AUTOTITLE = 'AUTOTITLE'
@@ -94,10 +83,7 @@ async function updateFile(file, context, opts) {
   const replacements = []
   const warnings = []
 
-  // The day we know with confidence that everyone us on Node >=17,
-  // we can change this to use `structuredClone` without the polyfill
-  // technique.
-  const newData = objectClone(data)
+  const newData = structuredClone(data)
 
   const ANY = Symbol('any')
   const IS_ARRAY = Symbol('is array')
