Add error for redirect during prerendering

Author: ijjk

errors/gsp-redirect-during-prerender.md

@@ -0,0 +1,13 @@
+# Redirect During getStaticProps Prerendering
+
+#### Why This Error Occurred
+
+The `redirect` value was returned from `getStaticProps` during prerendering which is invalid.
+
+#### Possible Ways to Fix It
+
+Remove any paths that result in a redirect from being prerendered in `getStaticPaths` and enable `fallback: true` to handle redirecting for these pages.
+
+### Useful Links
+
+- [Data Fetching Documentation](https://nextjs.org/docs/basic-features/data-fetching#getstaticprops-static-generation)

packages/next/next-server/server/render.tsx

@@ -591,6 +591,13 @@ export async function renderToHTML(
       if (data.redirect && typeof data.redirect === 'object') {
         checkRedirectValues(data.redirect, req)
 
+        if (isBuildTimeSSG) {
+          throw new Error(
+            `\`redirect\` can not be returned from getStaticProps during prerendering (${req.url})\n` +
+              `See more info here: https://err.sh/next.js/gsp-redirect-during-prerender`
+          )
+        }
+
         if (isDataReq) {
           data.props = {
             __N_REDIRECT: data.redirect.destination,

test/integration/gssp-redirect/test/index.test.js

@@ -212,4 +212,42 @@ describe('GS(S)P Redirect Support', () => {
 
     runTests()
   })
+
+  it('should error for redirect during prerendering', async () => {
+    await fs.mkdirp(join(appDir, 'pages/invalid'))
+    await fs.writeFile(
+      join(appDir, 'pages', 'invalid', '[slug].js'),
+      `
+        export default function Post(props) {
+          return "hi"
+        }
+
+        export const getStaticProps = ({ params }) => {
+          return {
+            redirect: {
+              permanent: true,
+              destination: '/another'
+            }
+          }
+        }
+
+        export const getStaticPaths = () => {
+          return {
+            paths: ['first', 'second'].map((slug) => ({ params: { slug } })),
+            fallback: true,
+          }
+        }
+      `
+    )
+    const { stdout, stderr } = await nextBuild(appDir, undefined, {
+      stdout: true,
+      stderr: true,
+    })
+    const output = stdout + stderr
+    await fs.remove(join(appDir, 'pages/invalid'))
+
+    expect(output).toContain(
+      '`redirect` can not be returned from getStaticProps during prerendering'
+    )
+  })
 })