[Cache Components] Validate static shell using dev stream

packages/next/errors.json

@@ -898,5 +898,6 @@
   "897": "Expected HTML document to start with doctype prefix",
   "898": "When using Cache Components, all `generateStaticParams` functions must return at least one result. This is to ensure that we can perform build-time validation that there is no other dynamic accesses that would cause a runtime error.\n\nLearn more: https://nextjs.org/docs/messages/empty-generate-static-params",
   "899": "Both \"%s\" and \"%s\" files are detected. Please use \"%s\" instead. Learn more: https://nextjs.org/docs/messages/middleware-to-proxy",
-  "900": "Both %s file \"./%s\" and %s file \"./%s\" are detected. Please use \"./%s\" only. Learn more: https://nextjs.org/docs/messages/middleware-to-proxy"
+  "900": "Both %s file \"./%s\" and %s file \"./%s\" are detected. Please use \"./%s\" only. Learn more: https://nextjs.org/docs/messages/middleware-to-proxy",
+  "901": "`accumulateStringChunks` received a chunk after deadline"
 }

packages/next/src/server/app-render/app-render-render-utils.ts

@@ -38,46 +38,55 @@ export function scheduleInSequentialTasks<R>(
 export function pipelineInSequentialTasks<A, B, C>(
   one: () => A,
   two: (a: A) => B,
-  three: (b: B) => C | Promise<C>
+  three: (b: B) => C
 ): Promise<C> {
   if (process.env.NEXT_RUNTIME === 'edge') {
     throw new InvariantError(
       '`pipelineInSequentialTasks` should not be called in edge runtime.'
     )
   } else {
     return new Promise((resolve, reject) => {
-      let oneResult: A | undefined = undefined
+      let oneResult: A
       setTimeout(() => {
         try {
           oneResult = one()
         } catch (err) {
           clearTimeout(twoId)
           clearTimeout(threeId)
+          clearTimeout(fourId)
           reject(err)
         }
       }, 0)
 
-      let twoResult: B | undefined = undefined
+      let twoResult: B
       const twoId = setTimeout(() => {
         // if `one` threw, then this timeout would've been cleared,
         // so if we got here, we're guaranteed to have a value.
         try {
           twoResult = two(oneResult!)
         } catch (err) {
           clearTimeout(threeId)
+          clearTimeout(fourId)
           reject(err)
         }
       }, 0)
 
+      let threeResult: C
       const threeId = setTimeout(() => {
         // if `two` threw, then this timeout would've been cleared,
         // so if we got here, we're guaranteed to have a value.
         try {
-          resolve(three(twoResult!))
+          threeResult = three(twoResult!)
         } catch (err) {
+          clearTimeout(fourId)
           reject(err)
         }
       }, 0)
+
+      // We wait a task before resolving/rejecting
+      const fourId = setTimeout(() => {
+        resolve(threeResult)
+      }, 0)
     })
   }
 }