File system uses fetch and pages cache only at build phase (#124)

* Chore: Bump version to 2.1.5

* Fix: Only write cache during production build phase

Author: AyronK

packages/nextjs-cache-handler/package-lock.json

@@ -18,7 +18,7 @@
     "next",
     "redis"
   ],
-  "version": "2.1.4",
+  "version": "2.1.5",
   "type": "module",
   "license": "MIT",
   "description": "Next.js cache handlers",

packages/nextjs-cache-handler/package.json

@@ -24,6 +24,7 @@ import {
   SetIncrementalFetchCacheContext,
 } from "next/dist/server/response-cache/types";
 import { resolveRevalidateValue } from "../helpers/resolveRevalidateValue";
+import { PHASE_PRODUCTION_BUILD } from "next/constants.js";
 
 const PRERENDER_MANIFEST_VERSION = 4;
 
@@ -741,14 +742,21 @@ export class CacheHandler implements NextCacheHandler {
 
     await CacheHandler.#mergedHandler.set(cacheKey, cacheHandlerValue);
 
-    if (hasFallbackFalse && cacheHandlerValue.value?.kind === "APP_PAGE") {
+    if (
+      process.env.NEXT_PHASE === PHASE_PRODUCTION_BUILD &&
+      hasFallbackFalse &&
+      cacheHandlerValue.value?.kind === "APP_PAGE"
+    ) {
       await CacheHandler.#writePagesRouterPage(
         cacheKey,
         cacheHandlerValue.value as unknown as IncrementalCachedPageValue,
       );
     }
 
-    if (cacheHandlerValue.value?.kind === "FETCH") {
+    if (
+      process.env.NEXT_PHASE === PHASE_PRODUCTION_BUILD &&
+      cacheHandlerValue.value?.kind === "FETCH"
+    ) {
       await CacheHandler.#writeFetch(
         cacheKey,
         cacheHandlerValue.value as unknown as CachedFetchValue,