fix: empty generateStaticParams should still create an ISR route

vercel · Dec 9, 2024 · cdae93f · cdae93f
1 parent 2fcba15
commit cdae93f
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Showing 7 changed files with 96 additions and 15 deletions.
diff --git a/packages/next/src/build/index.ts b/packages/next/src/build/index.ts
@@ -2278,10 +2278,7 @@ export default async function build(
                             })
                           }
 
-                          if (
-                            workerResult.prerenderedRoutes &&
-                            workerResult.prerenderedRoutes.length > 0
-                          ) {
+                          if (Array.isArray(workerResult.prerenderedRoutes)) {
                             staticPaths.set(
                               originalAppPath,
                               workerResult.prerenderedRoutes
@@ -2294,9 +2291,9 @@ export default async function build(
 
                           const appConfig = workerResult.appConfig || {}
                           if (appConfig.revalidate !== 0) {
-                            const hasGenerateStaticParams =
-                              workerResult.prerenderedRoutes &&
-                              workerResult.prerenderedRoutes.length > 0
+                            const hasGenerateStaticParams = Array.isArray(
+                              workerResult.prerenderedRoutes
+                            )
 
                             if (
                               config.output === 'export' &&

diff --git a/packages/next/src/build/utils.ts b/packages/next/src/build/utils.ts
@@ -1382,6 +1382,9 @@ export async function buildAppStaticPaths({
     }
   )
 
+  let dynamicParams = true
+  let hasGenerateStaticParams = false
+
   for (const segment of segments) {
     // Check to see if there are any missing params for segments that have
     // dynamicParams set to false.
@@ -1402,6 +1405,17 @@ export async function buildAppStaticPaths({
         )
       }
     }
+
+    // TODO: dynamic params should be allowed to be granular per segment but
+    // we need additional information stored/leveraged in the prerender
+    // manifest to allow this behavior.
+    if (segment.config?.dynamicParams === false) {
+      dynamicParams = false
+    }
+
+    if (segment.generateStaticParams) {
+      hasGenerateStaticParams = true
+    }
   }
 
   // Determine if all the segments have had their parameters provided. If there
@@ -1417,13 +1431,6 @@ export async function buildAppStaticPaths({
         return true
       }))
 
-  // TODO: dynamic params should be allowed to be granular per segment but
-  // we need additional information stored/leveraged in the prerender
-  // manifest to allow this behavior.
-  const dynamicParams = segments.every(
-    (segment) => segment.config?.dynamicParams !== false
-  )
-
   const supportsRoutePreGeneration =
     hadAllParamsGenerated || process.env.NODE_ENV === 'production'
 
@@ -1437,7 +1444,7 @@ export async function buildAppStaticPaths({
 
   let result: PartialStaticPathsResult = {
     fallbackMode,
-    prerenderedRoutes: undefined,
+    prerenderedRoutes: hasGenerateStaticParams ? [] : undefined,
   }
 
   if (hadAllParamsGenerated && fallbackMode) {

diff --git a/test/production/app-dir/empty-generate-static-params/app/[slug]/page.tsx b/test/production/app-dir/empty-generate-static-params/app/[slug]/page.tsx
@@ -0,0 +1,24 @@
+import { Suspense } from 'react'
+
+export default async function Page({
+  params,
+}: {
+  params: Promise<{ slug: string }>
+}) {
+  return (
+    <div>
+      Hello World
+      <div>
+        <Params params={params} />
+      </div>
+    </div>
+  )
+}
+
+async function Params({ params }: { params: Promise<{ slug: string }> }) {
+  return <Suspense>{(await params).slug}</Suspense>
+}
+
+export async function generateStaticParams() {
+  return []
+}
diff --git a/test/production/app-dir/empty-generate-static-params/app/layout.tsx b/test/production/app-dir/empty-generate-static-params/app/layout.tsx
@@ -0,0 +1,10 @@
+import { ReactNode, Suspense } from 'react'
+export default function Root({ children }: { children: ReactNode }) {
+  return (
+    <html>
+      <body>
+        <Suspense>{children}</Suspense>
+      </body>
+    </html>
+  )
+}
diff --git a/test/production/app-dir/empty-generate-static-params/app/page.tsx b/test/production/app-dir/empty-generate-static-params/app/page.tsx
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <p>hello world</p>
+}
diff --git a/test/production/app-dir/empty-generate-static-params/empty-generate-static-params.test.ts b/test/production/app-dir/empty-generate-static-params/empty-generate-static-params.test.ts
@@ -0,0 +1,34 @@
+import { nextTestSetup } from 'e2e-utils'
+import { retry } from 'next-test-utils'
+
+describe('empty-generate-static-params', () => {
+  const { next, skipped } = nextTestSetup({
+    files: __dirname,
+    skipDeployment: true,
+  })
+
+  if (skipped) return
+
+  it('should mark the page with empty generateStaticParams as SSG in build output', async () => {
+    const isPPREnabled = process.env.__NEXT_EXPERIMENTAL_PPR === 'true'
+    expect(next.cliOutput).toContain(`${isPPREnabled ? '◐' : '●'} /[slug]`)
+  })
+
+  it('should be a cache miss on the initial render followed by a HIT after being generated', async () => {
+    const firstResponse = await next.fetch('/foo')
+    expect(firstResponse.status).toBe(200)
+
+    // With PPR enabled, the initial request doesn't send back a cache header
+    const isPPREnabled = process.env.__NEXT_EXPERIMENTAL_PPR === 'true'
+
+    expect(firstResponse.headers.get('x-nextjs-cache')).toBe(
+      isPPREnabled ? null : 'MISS'
+    )
+
+    retry(async () => {
+      const secondResponse = await next.fetch('/foo')
+      expect(secondResponse.status).toBe(200)
+      expect(secondResponse.headers.get('x-nextjs-cache')).toBe('HIT')
+    })
+  })
+})
diff --git a/test/production/app-dir/empty-generate-static-params/next.config.js b/test/production/app-dir/empty-generate-static-params/next.config.js
@@ -0,0 +1,6 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+const nextConfig = {}
+
+module.exports = nextConfig