Added keyPrefix option, plus some trivial fixes

Signed-off-by: Slava Fomin <slava@fomin.io>

.gitignore

@@ -1,3 +1,4 @@
+/.idea/
 node_modules/
 package-lock.json
 *.tsbuildinfo

src/rateLimiter.ts

@@ -29,19 +29,20 @@ import { RedisStore } from "./redisStore.ts";
 export const limit = <C extends Context, RT extends RedisType>(
   userOptions?: OptionsInterface<C, RT>,
 ) => {
-  const options = { ...defaultOptions, ...userOptions };
+  const options = { ...defaultOptions, ...(userOptions ?? {}) };
   const store = options.storageClient === "MEMORY_STORE"
     ? new MemoryStore(options.timeFrame)
     : new RedisStore(options.storageClient as RT, options.timeFrame);
 
+  const keyPrefix = userOptions?.keyPrefix ?? defaultOptions.keyPrefix;
+
   const middlewareFunc = async (ctx: C, next: NextFunction) => {
-    const keyCheck = options.keyGenerator(ctx);
-    if (!keyCheck) {
+    const key = options.keyGenerator(ctx);
+    if (!key) {
       return await next();
     }
 
-    const key = "RATE_LIMITER" + keyCheck;
-    const hits = await store.increment(key);
+    const hits = await store.increment(keyPrefix + key);
 
     if (hits === options.limit + 1 || (options.alwaysReply && hits > options.limit)) {
       return options.onLimitExceeded(ctx, next);

src/typesAndDefaults.ts

@@ -54,17 +54,24 @@ export interface OptionsInterface<C extends Context, RT extends RedisType> {
 
   /**
    * @param ctx Is the context object you get from grammy/telegraf.
-   * @returns A number in **string** format as the unique key (identifier).
-   * @description A function to generate a unique key for every user. You cound set it as any key you want (e.g group id)
+   * @returns A unique **string** key (identifier).
+   * @description A function to generate a unique key for every user. You could set it as any key you want (e.g. group id)
    * @see [Getting Started](https://github.com/Amir-Zouerami/rateLimiter#-how-to-use)
    */
   keyGenerator?: (ctx: C) => string | undefined;
+
+  /**
+   * @default "RATE_LIMITER"
+   * @description A string prefix that is getting added to the storage key after calling the `keyGenerator()`.
+   */
+  keyPrefix?: string | undefined;
 }
 
-export const defaultOptions = {
+export const defaultOptions: OptionsInterface<Context, RedisType> = {
   timeFrame: 1000,
   limit: 1,
   onLimitExceeded: (_ctx: Context, _next: NextFunction) => {},
   storageClient: "MEMORY_STORE",
-  keyGenerator: (ctx: Context) => ctx.from === undefined ? undefined : ctx.from.id.toString(),
+  keyGenerator: (ctx: Context) => ctx.from?.id.toString(),
+  keyPrefix: "RATE_LIMITER",
 };