Fix unexpected object mutation while resolving Open Graph

Modifying an object passed from external sources can unintentionally lead to unpredictable behavior.

By changing the implementation from in-place object modification to returning a new object, we can make the method more predictable.

fixes #49501

packages/next/src/lib/metadata/resolvers/resolve-opengraph.test.ts

@@ -0,0 +1,23 @@
+import { resolveImages } from './resolve-opengraph'
+
+describe('resolveImages', () => {
+  const image1 = 'https://www.example.com/image1.jpg'
+  const image2 = 'https://www.example.com/image2.jpg'
+
+  it(`should resolve images`, () => {
+    const images = [image1, { url: image2, alt: 'Image2' }]
+
+    expect(resolveImages(images, null)).toEqual([
+      { url: new URL(image1) },
+      { url: new URL(image2), alt: 'Image2' },
+    ])
+  })
+
+  it('should not mutate passed images', () => {
+    const images = [image1, { url: image2, alt: 'Image2' }]
+
+    resolveImages(images, null)
+
+    expect(images).toEqual([image1, { url: image2, alt: 'Image2' }])
+  })
+})

packages/next/src/lib/metadata/resolvers/resolve-opengraph.ts

@@ -29,32 +29,33 @@ const OgTypeFields = {
   ],
 } as const
 
-function resolveImages(
+export function resolveImages(
   images: Twitter['images'],
   metadataBase: ResolvedMetadata['metadataBase']
 ): NonNullable<ResolvedMetadata['twitter']>['images']
-function resolveImages(
+export function resolveImages(
   images: OpenGraph['images'],
   metadataBase: ResolvedMetadata['metadataBase']
 ): NonNullable<ResolvedMetadata['openGraph']>['images']
-function resolveImages(
+export function resolveImages(
   images: OpenGraph['images'] | Twitter['images'],
   metadataBase: ResolvedMetadata['metadataBase']
 ):
   | NonNullable<ResolvedMetadata['twitter']>['images']
   | NonNullable<ResolvedMetadata['openGraph']>['images'] {
-  const resolvedImages = resolveAsArrayOrUndefined(images)
-  resolvedImages?.forEach((item, index, array) => {
+  return resolveAsArrayOrUndefined(images)?.map((item, index) => {
     if (isStringOrURL(item)) {
-      array[index] = {
+      return {
         url: resolveUrl(item, metadataBase)!,
       }
     } else {
-      // Update image descriptor url
-      item.url = resolveUrl(item.url, metadataBase)!
+      return {
+        ...item,
+        // Update image descriptor url
+        url: resolveUrl(item.url, metadataBase)!,
+      }
     }
   })
-  return resolvedImages
 }
 
 function getFieldsByOgType(ogType: OpenGraphType | undefined) {