From 5d793e8ccc7fa5838cf6f84c3c8bee202db0db97 Mon Sep 17 00:00:00 2001
From: Zack Tanner <zacktanner@gmail.com>
Date: Wed, 31 Jan 2024 12:17:32 -0800
Subject: [PATCH] tweak prefetched argument to router cache utils (#61177)

No behavior changes here, purely renaming this argument as I found it
confusing while working on a router cache bug. It's not strictly
representing if a cache node was prefetched, but rather if the prefetch
entry exists & can be re-used, since it could be that it was prefetched
but had a prefetch status of stale/expired.

Closes NEXT-2245
---
 .../components/router-reducer/apply-flight-data.ts   |  6 +++---
 .../fill-cache-with-new-subtree-data.ts              |  6 +++---
 .../fill-lazy-items-till-leaf-with-head.ts           | 12 ++++++------
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/packages/next/src/client/components/router-reducer/apply-flight-data.ts b/packages/next/src/client/components/router-reducer/apply-flight-data.ts
index 5003f47cbf5cf..7216636d5b0f2 100644
--- a/packages/next/src/client/components/router-reducer/apply-flight-data.ts
+++ b/packages/next/src/client/components/router-reducer/apply-flight-data.ts
@@ -7,7 +7,7 @@ export function applyFlightData(
   existingCache: CacheNode,
   cache: CacheNode,
   flightDataPath: FlightDataPath,
-  wasPrefetched: boolean = false
+  hasReusablePrefetch: boolean = false
 ): boolean {
   // The one before last item is the router state tree patch
   const [treePatch, cacheNodeSeedData, head] = flightDataPath.slice(-3)
@@ -32,7 +32,7 @@ export function applyFlightData(
       treePatch,
       cacheNodeSeedData,
       head,
-      wasPrefetched
+      hasReusablePrefetch
     )
   } else {
     // Copy rsc for the root node of the cache.
@@ -47,7 +47,7 @@ export function applyFlightData(
       cache,
       existingCache,
       flightDataPath,
-      wasPrefetched
+      hasReusablePrefetch
     )
   }
 
diff --git a/packages/next/src/client/components/router-reducer/fill-cache-with-new-subtree-data.ts b/packages/next/src/client/components/router-reducer/fill-cache-with-new-subtree-data.ts
index 78768ad778d94..8d254203e74c5 100644
--- a/packages/next/src/client/components/router-reducer/fill-cache-with-new-subtree-data.ts
+++ b/packages/next/src/client/components/router-reducer/fill-cache-with-new-subtree-data.ts
@@ -14,7 +14,7 @@ export function fillCacheWithNewSubTreeData(
   newCache: CacheNode,
   existingCache: CacheNode,
   flightDataPath: FlightDataPath,
-  wasPrefetched?: boolean
+  hasReusablePrefetch?: boolean
 ): void {
   const isLastEntry = flightDataPath.length <= 5
   const [parallelRouteKey, segment] = flightDataPath
@@ -71,7 +71,7 @@ export function fillCacheWithNewSubTreeData(
         flightDataPath[2],
         seedData,
         flightDataPath[4],
-        wasPrefetched
+        hasReusablePrefetch
       )
 
       childSegmentMap.set(cacheKey, childCacheNode)
@@ -99,6 +99,6 @@ export function fillCacheWithNewSubTreeData(
     childCacheNode,
     existingChildCacheNode,
     flightDataPath.slice(2),
-    wasPrefetched
+    hasReusablePrefetch
   )
 }
diff --git a/packages/next/src/client/components/router-reducer/fill-lazy-items-till-leaf-with-head.ts b/packages/next/src/client/components/router-reducer/fill-lazy-items-till-leaf-with-head.ts
index 1a596c4bb5cff..48b4c831a9fe1 100644
--- a/packages/next/src/client/components/router-reducer/fill-lazy-items-till-leaf-with-head.ts
+++ b/packages/next/src/client/components/router-reducer/fill-lazy-items-till-leaf-with-head.ts
@@ -11,7 +11,7 @@ export function fillLazyItemsTillLeafWithHead(
   routerState: FlightRouterState,
   cacheNodeSeedData: CacheNodeSeedData | null,
   head: React.ReactNode,
-  wasPrefetched?: boolean
+  hasReusablePrefetch?: boolean
 ): void {
   const isLastSegment = Object.keys(routerState[1]).length === 0
   if (isLastSegment) {
@@ -59,9 +59,9 @@ export function fillLazyItemsTillLeafWithHead(
             prefetchRsc: null,
             parallelRoutes: new Map(existingCacheNode?.parallelRoutes),
           }
-        } else if (wasPrefetched && existingCacheNode) {
+        } else if (hasReusablePrefetch && existingCacheNode) {
           // No new data was sent from the server, but the existing cache node
-          // was prefetched, so we should reuse that.
+          // has a non-expired prefetch, so we should reuse that.
           newCacheNode = {
             lazyData: existingCacheNode.lazyData,
             rsc: existingCacheNode.rsc,
@@ -72,7 +72,7 @@ export function fillLazyItemsTillLeafWithHead(
             parallelRoutes: new Map(existingCacheNode.parallelRoutes),
           } as CacheNode
         } else {
-          // No data available for this node. This will trigger a lazy fetch
+          // No data available for this node, or the prefetch entry expired. This will trigger a lazy fetch
           // during render.
           newCacheNode = {
             lazyData: null,
@@ -91,7 +91,7 @@ export function fillLazyItemsTillLeafWithHead(
           parallelRouteState,
           parallelSeedData ? parallelSeedData : null,
           head,
-          wasPrefetched
+          hasReusablePrefetch
         )
 
         newCache.parallelRoutes.set(key, parallelRouteCacheNode)
@@ -133,7 +133,7 @@ export function fillLazyItemsTillLeafWithHead(
       parallelRouteState,
       parallelSeedData,
       head,
-      wasPrefetched
+      hasReusablePrefetch
     )
   }
 }