fix: serialize map<string,buffer> into json

src/RedisStringsHandler.ts

@@ -2,7 +2,7 @@ import { commandOptions, createClient, RedisClientOptions } from 'redis';
 import { SyncedMap } from './SyncedMap';
 import { DeduplicatedRequestHandler } from './DeduplicatedRequestHandler';
 import { debug } from './utils/debug';
-import { bufferReviver, bufferReplacer } from './utils/json';
+import { bufferAndMapReviver, bufferAndMapReplacer } from './utils/json';
 
 export type CommandOptions = ReturnType<typeof commandOptions>;
 export type Client = ReturnType<typeof createClient>;
@@ -405,7 +405,7 @@ export default class RedisStringsHandler {
 
       const cacheEntry: CacheEntry | null = JSON.parse(
         serializedCacheEntry,
-        bufferReviver,
+        bufferAndMapReviver,
       );
 
       debug(
@@ -606,7 +606,10 @@ export default class RedisStringsHandler {
         tags: ctx?.tags || [],
         value: data,
       };
-      const serializedCacheEntry = JSON.stringify(cacheEntry, bufferReplacer);
+      const serializedCacheEntry = JSON.stringify(
+        cacheEntry,
+        bufferAndMapReplacer,
+      );
 
       // pre seed data into deduplicated get client. This will reduce redis load by not requesting
       // the same value from redis which was just set.

src/utils/json.ts

@@ -1,12 +1,25 @@
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export function bufferReviver(_: string, value: any): any {
+export function bufferAndMapReviver(_: string, value: any): any {
   if (value && typeof value === 'object' && typeof value.$binary === 'string') {
     return Buffer.from(value.$binary, 'base64');
   }
+  if (
+    value &&
+    typeof value === 'object' &&
+    typeof value.$map === 'object' &&
+    !!value.$map
+  ) {
+    return new Map(
+      Object.entries(value.$map).map(([key, value]) => {
+        const revivedValue = bufferAndMapReviver('', value);
+        return [key, revivedValue];
+      }),
+    );
+  }
   return value;
 }
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export function bufferReplacer(_: string, value: any): any {
+export function bufferAndMapReplacer(_: string, value: any): any {
   if (Buffer.isBuffer(value)) {
     return {
       $binary: value.toString('base64'),
@@ -22,5 +35,15 @@ export function bufferReplacer(_: string, value: any): any {
       $binary: Buffer.from(value.data).toString('base64'),
     };
   }
+  if (value && typeof value === 'object' && value instanceof Map) {
+    return {
+      $map: Object.fromEntries(
+        Array.from(value.entries()).map(([key, value]) => {
+          const replacedValue = bufferAndMapReplacer('', value);
+          return [key, replacedValue];
+        }),
+      ),
+    };
+  }
   return value;
 }