add(dev-overrides): In memory tagCache with nextMode

.changeset/few-wombats-design.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": patch
+---
+
+add(dev-overrides): In memory tagCache with nextMode

examples/app-router/open-next.config.local.ts

@@ -7,7 +7,7 @@ export default {
       converter: "node",
       incrementalCache: "fs-dev",
       queue: "direct",
-      tagCache: "dummy",
+      tagCache: "fs-dev-nextMode",
     },
   },
 

packages/open-next/src/overrides/tagCache/fs-dev-nextMode.ts

@@ -0,0 +1,90 @@
+import fs from "node:fs";
+import path from "node:path";
+
+import type { NextModeTagCache } from "types/overrides";
+import { getMonorepoRelativePath } from "utils/normalize-path";
+import { debug } from "../../adapters/logger";
+
+const tagFile = path.join(
+  getMonorepoRelativePath(),
+  "dynamodb-provider/dynamodb-cache.json",
+);
+const tagContent = fs.readFileSync(tagFile, "utf-8");
+
+let tags = JSON.parse(tagContent) as {
+  tag: { S: string };
+  path: { S: string };
+  revalidatedAt: { N: string };
+}[];
+
+function buildKey(key: string) {
+  const { NEXT_BUILD_ID } = process.env;
+  return path.posix.join(NEXT_BUILD_ID ?? "", key);
+}
+
+function buildObject(tag: string, revalidatedAt?: number) {
+  return {
+    path: { S: buildKey(tag) },
+    tag: { S: buildKey(tag) },
+    revalidatedAt: { N: `${revalidatedAt ?? Date.now()}` },
+  };
+}
+
+export default {
+  name: "fs-dev-nextMode",
+  mode: "nextMode",
+  getLastRevalidated: async (tagsToCheck: string[]) => {
+    // Not supported for now
+    // TODO: Implement getLastRevalidated
+    return 0;
+  },
+  hasBeenRevalidated: async (tagsToCheck: string[], lastModified?: number) => {
+    if (globalThis.openNextConfig.dangerous?.disableTagCache) {
+      return false;
+    }
+    debug("hasBeenRevalidated", { tags: tagsToCheck, lastModified });
+
+    // Build the cache keys for the tags we're checking
+    const cacheKeys = tagsToCheck.map((tag) => buildKey(tag));
+
+    // Check if any tag has been revalidated after the lastModified time
+    const hasRevalidatedTag = tags.some((tagEntry) => {
+      const tagRevalidatedAt = Number.parseInt(tagEntry.revalidatedAt.N);
+      return (
+        cacheKeys.includes(tagEntry.tag.S) &&
+        tagRevalidatedAt > (lastModified ?? Date.now())
+      );
+    });
+
+    debug("hasBeenRevalidated result:", hasRevalidatedTag);
+    return hasRevalidatedTag;
+  },
+  writeTags: async (tagsToWrite: string[]) => {
+    if (
+      globalThis.openNextConfig.dangerous?.disableTagCache ||
+      tagsToWrite.length === 0
+    ) {
+      return Promise.resolve();
+    }
+
+    debug("writeTags", { tags: tagsToWrite });
+
+    // Create new tag objects to write
+    const newTagObjects = tagsToWrite.map((tag) =>
+      buildObject(tag, Date.now()),
+    );
+
+    // Remove any existing entries for these tags to avoid duplicates
+    const existingTagKeys = newTagObjects.map((obj) => obj.tag.S);
+    tags = tags.filter((tagEntry) => !existingTagKeys.includes(tagEntry.tag.S));
+
+    // Add the new tags
+    tags.push(...newTagObjects);
+
+    fs.writeFileSync(tagFile, JSON.stringify(tags));
+
+    debug("writeTags completed, written", newTagObjects.length, "tags");
+
+    return Promise.resolve();
+  },
+} satisfies NextModeTagCache;

packages/open-next/src/types/open-next.ts

@@ -175,6 +175,7 @@ export type IncludedTagCache =
   | "dynamodb-lite"
   | "dynamodb-nextMode"
   | "fs-dev"
+  | "fs-dev-nextMode"
   | "dummy";
 
 export type IncludedImageLoader =