allow use existing driver

index.ts

@@ -2,3 +2,4 @@ export * from './src/aragami';
 export * from './src/def';
 export * from './src/decorators';
 export * from './src/wrappers';
+export * from './src/drivers';

src/aragami.ts

 import { BaseDriver } from './base-driver';
 import { AnyClass, AragamiOptions, Awaitable, ClassType } from './def';
-import { RedisDriver } from './drivers/redis';
-import { MemoryDriver } from './drivers/memory';
 import { reflector } from './metadata';
 import { encode, decode } from 'encoded-buffer';
 
 import { makeArray, MayBeArray } from './utility/utility';
 import { PartialDeep } from './utility/partial-deep';
 import { wrapClass } from './utility/encode-decode';
+import { MemoryDriver, RedisDriver } from './drivers';
 
 export class Aragami {
   readonly driver: BaseDriver;
 
   constructor(private options: AragamiOptions = {}) {
-    this.driver = options.redis
-      ? new RedisDriver(options.redis)
-      : new MemoryDriver();
+    this.driver =
+      options.useDriver ||
+      (options.redis ? new RedisDriver(options.redis) : new MemoryDriver());
   }
 
   private getBaseKey(o: string | any): string {

src/def.ts

 import { RedisOptions } from 'ioredis';
 import { Settings } from '@sesamecare-oss/redlock';
+import { BaseDriver } from './base-driver';
 
 export type RedisDriverOptions = RedisOptions & {
   uri?: string;
@@ -13,6 +14,7 @@ export type RedisDriverOptions = RedisOptions & {
 };
 
 export interface AragamiOptions {
+  useDriver?: BaseDriver;
   redis?: RedisDriverOptions;
   defaultTTL?: number;
 }

src/drivers/index.ts

+export * from './memory';
+export * from './redis';