updated rate limiter options. sliding window log setup

Author: shalarewicz

src/@types/rateLimit.d.ts

@@ -44,11 +44,22 @@ export type RateLimiterSelection =
  * @type {number} refillRate - Rate at which tokens are added to the bucket in seconds
  */
 export interface TokenBucketOptions {
+    typename: 'bucket';
     bucketSize: number;
     refillRate: number;
 }
 
+/**
+ * @type {number} windowSize - size of the window in milliseconds
+ * @type {number} capacity - max number of tokens that can be used in the bucket
+ */
+export interface WindowOptions {
+    typename: 'window';
+    windowSize: number;
+    capacity: number;
+}
+
 // TODO: This will be a union type where we can specify Option types for other Rate Limiters
-// Record<string, never> represents the empty object for alogorithms that don't require settings
+// Record<string, never> represents the empty object for algorithms that don't require settings
 // and might be able to be removed in the future.
-export type RateLimiterOptions = TokenBucketOptions | Record<string, never>;
+export type RateLimiterOptions = TokenBucketOptions | WindowSize | Record<string, never>;

src/middleware/rateLimiterSetup.ts

@@ -1,5 +1,6 @@
 import Redis from 'ioredis';
 import { RateLimiterOptions, RateLimiterSelection } from '../@types/rateLimit';
+import SlidingWindowLog from '../rateLimiters/slidingWindowLog';
 import TokenBucket from '../rateLimiters/tokenBucket';
 
 /**
@@ -18,24 +19,23 @@ export default function setupRateLimiter(
 ) {
     switch (selection) {
         case 'TOKEN_BUCKET':
-            // todo validate options
-            return new TokenBucket(options.bucketSize, options.refillRate, client);
-            break;
+            if (options.typename === 'bucket') {
+                return new TokenBucket(options.bucketSize, options.refillRate, client);
+            }
+            throw new Error('Invalid options for token bucket');
         case 'LEAKY_BUCKET':
             throw new Error('Leaky Bucket algonithm has not be implemented.');
-            break;
         case 'FIXED_WINDOW':
             throw new Error('Fixed Window algonithm has not be implemented.');
-            break;
         case 'SLIDING_WINDOW_LOG':
-            throw new Error('Sliding Window Log has not be implemented.');
-            break;
+            if (options.typename === 'window') {
+                return new SlidingWindowLog(options.windowSize, options.capacity, client);
+            }
+            throw new Error('Invalid options for sliding window log');
         case 'SLIDING_WINDOW_COUNTER':
             throw new Error('Sliding Window Counter algonithm has not be implemented.');
-            break;
         default:
             // typescript should never let us invoke this function with anything other than the options above
             throw new Error('Selected rate limiting algorithm is not suppported');
-            break;
     }
 }