throw if no head to insert styles into

facebook · Sep 28, 2022 · 3a9ab9c · 3a9ab9c
1 parent e57f39d
commit 3a9ab9c
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Showing 3 changed files with 37 additions and 7 deletions.
diff --git a/packages/react-dom/src/__tests__/ReactDOMFloat-test.js b/packages/react-dom/src/__tests__/ReactDOMFloat-test.js
@@ -229,6 +229,24 @@ describe('ReactDOMFloat', () => {
     return readText(text);
   }
 
+  it('errors if the document does not contain a head when inserting a resource', async () => {
+    document.head.parentNode.removeChild(document.head);
+    const root = ReactDOMClient.createRoot(document);
+    root.render(
+      <html>
+        <body>
+          <link rel="stylesheet" href="foo" precedence="default" />
+          foo
+        </body>
+      </html>,
+    );
+    expect(() => {
+      expect(Scheduler).toFlushWithoutYielding();
+    }).toThrow(
+      'While attempting to insert a Resource, React expected the Document to contain a head element but it was not found.',
+    );
+  });
+
   describe('HostResource', () => {
     // @gate enableFloat
     it('warns when you update props to an invalid type', async () => {

diff --git a/packages/react-dom/src/client/ReactDOMFloatClient.js b/packages/react-dom/src/client/ReactDOMFloatClient.js
@@ -736,13 +736,20 @@ function insertStyleInstance(
       break;
     }
   }
-  if (prior && prior.parentNode) {
-    prior.parentNode.insertBefore(instance, prior.nextSibling);
+  if (prior) {
+    // We get the prior from the document so we know it is in the tree.
+    // We also know that links can't be the topmost Node so the parentNode
+    // must exist.
+    ((prior.parentNode: any): Node).insertBefore(instance, prior.nextSibling);
   } else {
-    const parent =
-      ownerDocument.head || ownerDocument.body || ownerDocument.documentElement;
+    const parent = ownerDocument.head;
     if (parent) {
       parent.insertBefore(instance, parent.firstChild);
+    } else {
+      throw new Error(
+        'While attempting to insert a Resource, React expected the Document to contain' +
+          ' a head element but it was not found.',
+      );
     }
   }
 }
@@ -766,10 +773,14 @@ function insertPreloadInstance(
   ownerDocument: Document,
 ): void {
   if (!ownerDocument.contains(instance)) {
-    const parent =
-      ownerDocument.head || ownerDocument.body || ownerDocument.documentElement;
+    const parent = ownerDocument.head;
     if (parent) {
       parent.appendChild(instance);
+    } else {
+      throw new Error(
+        'While attempting to insert a Resource, React expected the Document to contain' +
+          ' a head element but it was not found.',
+      );
     }
   }
 }

diff --git a/scripts/error-codes/codes.json b/scripts/error-codes/codes.json
@@ -431,5 +431,6 @@
   "443": "acquireResource encountered a resource type it did not expect: \"%s\". this is a bug in React.",
   "444": "getResource encountered a resource type it did not expect: \"%s\". this is a bug in React.",
   "445": "\"currentResources\" was expected to exist. This is a bug in React.",
-  "446": "\"currentDocument\" was expected to exist. This is a bug in React."
+  "446": "\"currentDocument\" was expected to exist. This is a bug in React.",
+  "447": "While attempting to insert a Resource, React expected the Document to contain a head element but it was not found."
 }