feat: generate cache-life types during next build

packages/next/src/build/index.ts

@@ -218,6 +218,7 @@ import {
   writeRouteTypesManifest,
   writeValidatorFile,
   writeRouteTypesEntryFile,
+  writeCacheLifeTypesFile,
 } from '../server/lib/router-utils/route-types-utils'
 import { Lockfile } from './lockfile'
 import {
@@ -1406,6 +1407,20 @@ export default async function build(
             strictRouteTypes: Boolean(config.experimental.strictRouteTypes),
             typedRoutes: Boolean(config.typedRoutes),
           })
+
+          // Generate cache-life types if custom profiles are configured
+          if (config.cacheLife) {
+            routeTypesManifest.cacheLifeConfig = config.cacheLife
+            const cacheLifeTypesFilePath = path.join(
+              distDir,
+              'types',
+              'cache-life.d.ts'
+            )
+            await writeCacheLifeTypesFile(
+              routeTypesManifest,
+              cacheLifeTypesFilePath
+            )
+          }
         })
 
       // Turbopack already handles conflicting app and page routes.

packages/next/src/server/lib/router-utils/cache-life-type-utils.ts

@@ -1,4 +1,5 @@
 import type { CacheLife } from '../../use-cache/cache-life'
+import { INFINITE_CACHE } from '../../../lib/constants'
 import fs from 'fs'
 import path from 'path'
 
@@ -52,7 +53,7 @@ function formatTimespanWithSeconds(seconds: undefined | number): string {
   if (seconds === undefined) {
     return 'default'
   }
-  if (seconds >= 0xfffffffe) {
+  if (seconds >= INFINITE_CACHE) {
     return 'never'
   }
   const text = seconds + ' seconds'
@@ -86,7 +87,7 @@ export function generateCacheLifeTypes(cacheLife: {
     if (profile.stale === undefined) {
       description += `
      * This cache may be stale on clients for the default stale time of the scope before checking with the server.`
-    } else if (profile.stale >= 0xfffffffe) {
+    } else if (profile.stale >= INFINITE_CACHE) {
       description += `
      * This cache may be stale on clients indefinitely before checking with the server.`
     } else {
@@ -104,7 +105,7 @@ export function generateCacheLifeTypes(cacheLife: {
       if (profile.revalidate === undefined) {
         description += `
      * It will inherit the default revalidate time of its scope since it does not define its own.`
-      } else if (profile.revalidate >= 0xfffffffe) {
+      } else if (profile.revalidate >= INFINITE_CACHE) {
         // Nothing to mention.
       } else {
         description += `
@@ -113,7 +114,7 @@ export function generateCacheLifeTypes(cacheLife: {
       if (profile.expire === undefined) {
         description += `
      * It will inherit the default expiration time of its scope since it does not define its own.`
-      } else if (profile.expire >= 0xfffffffe) {
+      } else if (profile.expire >= INFINITE_CACHE) {
         description += `
      * It lives for the maximum age of the server cache. If this entry has no traffic for a while, it may serve an old value the next request.`
       } else {

packages/next/src/server/lib/router-utils/route-types-utils.ts

@@ -13,6 +13,7 @@ import {
   generateValidatorFileStrict,
   generateRouteTypesFileStrict,
 } from './typegen'
+import { writeCacheLifeTypes } from './cache-life-type-utils'
 import { tryToParsePath } from '../../../lib/try-to-parse-path'
 import {
   extractInterceptionRouteInformation,
@@ -24,6 +25,7 @@ import {
 } from '../../../shared/lib/entry-constants'
 import { normalizePathSep } from '../../../shared/lib/page-path/normalize-path-sep'
 import type { RouteInfo, SlotInfo } from '../../../build/file-classifier'
+import type { CacheLife } from '../../use-cache/cache-life'
 
 // Internal route info with extracted params for the manifest
 interface ManifestRouteInfo {
@@ -48,6 +50,8 @@ export interface RouteTypesManifest {
   pageApiRoutes: Set<string>
   /** Direct mapping from file paths to routes for validation */
   filePathToRoute: Map<string, string>
+  /** Cache life configuration for generating cache-life.d.ts */
+  cacheLifeConfig?: { [profile: string]: CacheLife }
 }
 
 // Convert a custom-route source string (`/blog/:slug`, `/docs/:path*`, ...)
@@ -445,3 +449,10 @@ export async function writeRouteTypesEntryFile(
 
   await fs.promises.writeFile(entryFilePath, lines.join('\n'))
 }
+
+export async function writeCacheLifeTypesFile(
+  manifest: RouteTypesManifest,
+  filePath: string
+) {
+  writeCacheLifeTypes(manifest.cacheLifeConfig, filePath)
+}