Add rolling rate limiter

types/rolling-rate-limiter/index.d.ts

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+// Type definitions for rolling-rate-limiter 0.1
+// Project: https://github.com/peterkhayes/rolling-rate-limiter
+// Definitions by: Jonas Lochmann <https://github.com/l-jonas>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+export = RollingRateLimiter;
+
+declare function RollingRateLimiter(options: RollingRateLimiter.InMemoryOptions): RollingRateLimiter.SyncOrAsyncLimiter;
+declare function RollingRateLimiter(options: RollingRateLimiter.WithRedisOptions): RollingRateLimiter.AsyncLimiter;
+
+declare namespace RollingRateLimiter {
+  interface GeneralOptions {
+    interval: number;
+    maxInInterval: number;
+    minDifference?: number;
+  }
+
+  interface RedisOptions {
+    redis: CompatibleRedisClient;
+    namespace?: string;
+  }
+
+  interface CompatibleRedisClient {
+    multi: () => any;
+  }
+
+  type InMemoryOptions = GeneralOptions;
+  type WithRedisOptions = GeneralOptions & RedisOptions;
+
+  type AsyncLimiterWithToken = (token: string, callback: AsyncLimiterCallback) => void;
+  type AsyncLimiterWithoutToken = (callback: AsyncLimiterCallback) => void;
+  type AsyncLimiterCallback = (err: any, timeLeft: number, actionsLeft: number) => void;
+  type AsyncLimiter = AsyncLimiterWithToken & AsyncLimiterWithToken;
+
+  type SyncLimiter = (token?: string) => number;
+
+  type SyncOrAsyncLimiter = SyncLimiter & AsyncLimiter;
+}

types/rolling-rate-limiter/rolling-rate-limiter-tests.ts

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+import * as RateLimiter from 'rolling-rate-limiter';
+
+/*
+  Setup:
+*/
+
+const limiter = RateLimiter({
+  // in miliseconds
+  interval: 1000,
+  maxInInterval: 10,
+  // optional: the minimum time (in miliseconds) between any two actions
+  minDifference: 100
+});
+
+/*
+  Action:
+*/
+
+function attemptAction(userId: string) {
+  // Argument should be a unique identifier for a user if one exists.
+  // If none is provided, the limiter will not differentiate between users.
+  const timeLeft = limiter(userId);
+
+  if (timeLeft > 0) {
+    // limit was exceeded, action should not be allowed
+    // timeLeft is the number of ms until the next action will be allowed
+    // note that this can be treated as a boolean, since 0 is falsy
+  } else {
+    // limit was not exceeded, action should be allowed
+  }
+}
+
+/*
+  Note that the in-memory version can also operate asynchronously.
+  The syntax is identical to the redis implementation below.
+*/

types/rolling-rate-limiter/tsconfig.json

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+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "rolling-rate-limiter-tests.ts"
+    ]
+}

types/rolling-rate-limiter/tslint.json

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+{ "extends": "dtslint/dt.json" }