feat(next): throw when twitter-image or opengraph-image file size exceeds

crates/next-core/src/next_app/metadata/route.rs

@@ -148,6 +148,15 @@ async fn static_route_source(
 
     let original_file_content_b64 = get_base64_file_content(path).await?;
 
+    let is_twitter = stem == "twitter-image";
+    let is_open_graph = stem == "opengraph-image";
+    // Twitter image file size limit is 5MB.
+    // General Open Graph image file size limit is 8MB.
+    // x-ref: https://developer.x.com/en/docs/x-for-websites/cards/overview/summary
+    // x-ref(facebook): https://developers.facebook.com/docs/sharing/webmasters/images
+    let file_size_limit = if is_twitter { 5 } else { 8 };
+    let img_name = if is_twitter { "Twitter" } else { "Open Graph" };
+
     let code = formatdoc! {
         r#"
             import {{ NextResponse }} from 'next/server'
@@ -156,6 +165,16 @@ async fn static_route_source(
             const cacheControl = {cache_control}
             const buffer = Buffer.from({original_file_content_b64}, 'base64')
 
+            if ({is_twitter} || {is_open_graph}) {{
+                const fileSizeInMB = buffer.byteLength / 1024 / 1024
+                if (fileSizeInMB > {file_size_limit}) {{
+                    throw new Error('File size for {img_name} image "{path}" exceeds {file_size_limit}MB. ' +
+                    `(Current: ${{fileSizeInMB.toFixed(2)}}MB)\n` +
+                    'Read more: https://nextjs.org/docs/app/api-reference/file-conventions/metadata/opengraph-image#image-files-jpg-png-gif'
+                    )
+                }}
+            }}
+
             export function GET() {{
                 return new NextResponse(buffer, {{
                     headers: {{
@@ -170,6 +189,11 @@ async fn static_route_source(
         content_type = StringifyJs(&content_type),
         cache_control = StringifyJs(cache_control),
         original_file_content_b64 = StringifyJs(&original_file_content_b64),
+        is_twitter = is_twitter,
+        is_open_graph = is_open_graph,
+        file_size_limit = file_size_limit,
+        img_name = img_name,
+        path = path.to_string().await?,
     };
 
     let file = File::from(code);

docs/02-app/02-api-reference/02-file-conventions/01-metadata/opengraph-image.mdx

@@ -25,6 +25,10 @@ Next.js will evaluate the file and automatically add the appropriate tags to you
 | [`opengraph-image.alt`](#opengraph-imagealttxt) | `.txt`                          |
 | [`twitter-image.alt`](#twitter-imagealttxt)     | `.txt`                          |
 
+> **Good to know**:
+>
+> The `twitter-image` file size must not exceed [5MB](https://developer.x.com/en/docs/x-for-websites/cards/overview/summary), and the `opengraph-image` file size must not exceed [8MB](https://developers.facebook.com/docs/sharing/webmasters/images). If the image file size exceeds these limits, the build will fail.
+
 ### `opengraph-image`
 
 Add an `opengraph-image.(jpg|jpeg|png|gif)` image file to any route segment.

packages/next/src/build/webpack/loaders/next-metadata-route-loader.ts

@@ -82,6 +82,16 @@ async function getStaticAssetRouteCode(
       : process.env.NODE_ENV !== 'production'
         ? cacheHeader.none
         : cacheHeader.longCache
+
+  const isTwitter = fileBaseName === 'twitter-image'
+  const isOpenGraph = fileBaseName === 'opengraph-image'
+  // Twitter image file size limit is 5MB.
+  // General Open Graph image file size limit is 8MB.
+  // x-ref: https://developer.x.com/en/docs/x-for-websites/cards/overview/summary
+  // x-ref(facebook): https://developers.facebook.com/docs/sharing/webmasters/images
+  const fileSizeLimit = isTwitter ? 5 : 8
+  const imgName = isTwitter ? 'Twitter' : 'Open Graph'
+
   const code = `\
 /* static asset route */
 import { NextResponse } from 'next/server'
@@ -92,6 +102,16 @@ const buffer = Buffer.from(${JSON.stringify(
   )}, 'base64'
   )
 
+if (${isTwitter || isOpenGraph}) {
+  const fileSizeInMB = buffer.byteLength / 1024 / 1024
+  if (fileSizeInMB > ${fileSizeLimit}) {
+    throw new Error('File size for ${imgName} image "${resourcePath}" exceeds ${fileSizeLimit}MB. ' +
+    \`(Current: \${fileSizeInMB.toFixed(2)}MB)\n\` +
+    'Read more: https://nextjs.org/docs/app/api-reference/file-conventions/metadata/opengraph-image#image-files-jpg-png-gif'
+    )
+  }
+}
+
 export function GET() {
   return new NextResponse(buffer, {
     headers: {

test/production/app-dir/metadata-img-too-large/generate-image.ts

@@ -0,0 +1,71 @@
+import zlib from 'zlib'
+
+const PNG_SIGNATURE = Buffer.from([137, 80, 78, 71, 13, 10, 26, 10])
+
+function createChunk(type, data) {
+  const length = Buffer.alloc(4)
+  length.writeUInt32BE(data.length, 0)
+  const crc = Buffer.alloc(4)
+  const crcValue = calculateCRC(Buffer.concat([Buffer.from(type), data])) >>> 0 // Ensure unsigned 32-bit integer
+  crc.writeUInt32BE(crcValue, 0)
+  return Buffer.concat([length, Buffer.from(type), data, crc])
+}
+
+function calculateCRC(data) {
+  let crc = 0xffffffff
+  for (const b of data) {
+    crc ^= b
+    for (let i = 0; i < 8; i++) {
+      crc = (crc >>> 1) ^ (crc & 1 ? 0xedb88320 : 0)
+    }
+  }
+  return crc ^ 0xffffffff
+}
+
+export function generatePNG(targetSizeMB) {
+  const targetSizeBytes = targetSizeMB * 1024 * 1024
+
+  let width = 2048,
+    height = 1024
+  let pngFile: Buffer
+
+  do {
+    const ihdrData = Buffer.alloc(13)
+    ihdrData.writeUInt32BE(width, 0)
+    ihdrData.writeUInt32BE(height, 4)
+    ihdrData.writeUInt8(8, 8) // bitDepth
+    ihdrData.writeUInt8(6, 9) // colorType
+    ihdrData.writeUInt8(0, 10) // compressionMethod
+    ihdrData.writeUInt8(0, 11) // filterMethod
+    ihdrData.writeUInt8(0, 12) // interlaceMethod
+
+    const ihdrChunk = createChunk('IHDR', ihdrData)
+
+    const rowSize = width * 4 + 1
+    const imageData = Buffer.alloc(rowSize * height)
+
+    for (let y = 0; y < height; y++) {
+      imageData[y * rowSize] = 0
+      for (let x = 0; x < width; x++) {
+        const idx = y * rowSize + 1 + x * 4
+        imageData[idx] = (Math.random() * 256) | 0
+        imageData[idx + 1] = (Math.random() * 256) | 0
+        imageData[idx + 2] = (Math.random() * 256) | 0
+        imageData[idx + 3] = 255
+      }
+    }
+
+    const compressedImageData = zlib.deflateSync(imageData)
+    const idatChunk = createChunk('IDAT', compressedImageData)
+    const iendChunk = createChunk('IEND', Buffer.alloc(0))
+
+    pngFile = Buffer.concat([PNG_SIGNATURE, ihdrChunk, idatChunk, iendChunk])
+
+    if (pngFile.length < targetSizeBytes) {
+      width *= 2
+      height *= 2
+    }
+  } while (pngFile.length < targetSizeBytes)
+
+  return pngFile
+}

test/production/app-dir/metadata-img-too-large/opengraph-image/app/layout.tsx

@@ -0,0 +1,8 @@
+import { ReactNode } from 'react'
+export default function Root({ children }: { children: ReactNode }) {
+  return (
+    <html>
+      <body>{children}</body>
+    </html>
+  )
+}

test/production/app-dir/metadata-img-too-large/opengraph-image/app/page.tsx

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <p>hello world</p>
+}

test/production/app-dir/metadata-img-too-large/opengraph-image/index.test.ts

@@ -0,0 +1,21 @@
+import { nextTestSetup } from 'e2e-utils'
+import { generatePNG } from '../generate-image'
+
+describe('app-dir - metadata-img-too-large opengraph-image', () => {
+  const { next } = nextTestSetup({
+    files: __dirname,
+    skipStart: true,
+  })
+
+  const pngFile = generatePNG(8)
+
+  it('should throw when opengraph-image file size exceeds 8MB', async () => {
+    await next.patchFile('app/opengraph-image.png', pngFile as any)
+
+    await next.build()
+    const { cliOutput } = next
+    expect(cliOutput).toMatch(
+      /Error: File size for Open Graph image ".*\/app\/opengraph-image\.png" exceeds 8MB/
+    )
+  })
+})

test/production/app-dir/metadata-img-too-large/opengraph-image/next.config.js

@@ -0,0 +1,6 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+const nextConfig = {}
+
+module.exports = nextConfig

test/production/app-dir/metadata-img-too-large/twitter-image/app/layout.tsx

@@ -0,0 +1,8 @@
+import { ReactNode } from 'react'
+export default function Root({ children }: { children: ReactNode }) {
+  return (
+    <html>
+      <body>{children}</body>
+    </html>
+  )
+}

test/production/app-dir/metadata-img-too-large/twitter-image/app/page.tsx

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <p>hello world</p>
+}

test/production/app-dir/metadata-img-too-large/twitter-image/index.test.ts

@@ -0,0 +1,21 @@
+import { nextTestSetup } from 'e2e-utils'
+import { generatePNG } from '../generate-image'
+
+describe('metadata-img-too-large twitter-image', () => {
+  const { next } = nextTestSetup({
+    files: __dirname,
+    skipStart: true,
+  })
+
+  const pngFile = generatePNG(6)
+
+  it('should throw when twitter-image file size exceeds 5MB', async () => {
+    await next.patchFile('app/twitter-image.png', pngFile as any)
+
+    await next.build()
+    const { cliOutput } = next
+    expect(cliOutput).toMatch(
+      /Error: File size for Twitter image ".*\/app\/twitter-image\.png" exceeds 5MB/
+    )
+  })
+})

test/production/app-dir/metadata-img-too-large/twitter-image/next.config.js

@@ -0,0 +1,6 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+const nextConfig = {}
+
+module.exports = nextConfig