add cursor and count params to scan (#12)

Author: noamilshtein

src/redis.ts

@@ -106,9 +106,8 @@ class buildRedisStoreWithConfig implements RedisStore {
     return await this.redisCache.ttl(key);
   };
 
-  public async scan(pattern: string): Promise<ScanReply> {
-    let cursor = 0;
-    return await this.redisCache.scan(cursor, {MATCH: pattern});
+  public async scan(pattern: string, cursor: number = 0, count: number = 10): Promise<ScanReply> {
+    return await this.redisCache.scan(cursor, { MATCH: pattern, COUNT: count });
   }
 
   public getClient(): RedisClientType<RedisDefaultModules & RedisModules, RedisFunctions, RedisScripts> {

src/types/RedisStore.interface.ts

@@ -7,5 +7,5 @@ export interface RedisStore extends Store {
 
   getClient(): RedisClientType<RedisDefaultModules & RedisModules, RedisFunctions, RedisScripts>;
 
-  scan(pattern: string): Promise<ScanReply>;
+  scan(pattern: string, cursor? :number, count?: number): Promise<ScanReply>;
 }

test/redis.test.ts

@@ -93,5 +93,18 @@ describe('Redis Store', () => {
 
     const res = await redisClient.scan('ttl:a:*');
     expect(res.keys).toEqual([key1, key3]);
+
+    const firstScanWithCount = await redisClient.scan('ttl:a:*', 0, 1);
+    expect(firstScanWithCount.keys).toEqual([key1]);
+    expect(firstScanWithCount.cursor).not.equal(0);
+
+    const secondScanWithCount = await redisClient.scan('ttl:a:*', firstScanWithCount.cursor, 1);
+    expect(secondScanWithCount.keys).toEqual([key3]);
+    expect(secondScanWithCount.cursor).equal(3);
+
+    const thirdScanWithCount = await redisClient.scan('ttl:a:*', secondScanWithCount.cursor, 1);
+    expect(thirdScanWithCount.keys).toEqual([]);
+    expect(thirdScanWithCount.cursor).equal(0);
+
   });
 });