corrected express middleware testing suite with refactor redis connect util and associated mock

Author: shalarewicz

package.json

@@ -5,11 +5,12 @@
     "main": "index.js",
     "type": "module",
     "scripts": {
-        "test": "jest --passWithNoTests --coverage",
+        "test": "jest --passWithNoTests --coverage --detectOpenHandles",
         "lint": "eslint src test",
         "lint:fix": "eslint --fix src test @types",
         "prettier": "prettier --write .",
-        "prepare": "husky install"
+        "prepare": "husky install",
+        "build": "tsc"
     },
     "repository": {
         "type": "git",
@@ -26,9 +27,9 @@
         "@babel/core": "^7.17.12",
         "@babel/preset-env": "^7.17.12",
         "@babel/preset-typescript": "^7.17.12",
+        "@types/express": "^4.17.13",
         "@types/ioredis": "^4.28.10",
         "@types/ioredis-mock": "^5.6.0",
-        "@types/express": "^4.17.13",
         "@types/jest": "^27.5.1",
         "@typescript-eslint/eslint-plugin": "^5.24.0",
         "@typescript-eslint/parser": "^5.24.0",
@@ -56,4 +57,4 @@
         "graphql": "^16.5.0",
         "ioredis": "^5.0.5"
     }
-}
+}

src/middleware/index.ts

@@ -1,5 +1,5 @@
-import Redis, { RedisOptions } from 'ioredis';
 import { parse, validate } from 'graphql';
+import { RedisOptions } from 'ioredis';
 import { GraphQLSchema } from 'graphql/type/schema';
 import { Request, Response, NextFunction, RequestHandler } from 'express';
 
@@ -8,6 +8,7 @@ import setupRateLimiter from './rateLimiterSetup';
 import getQueryTypeComplexity from '../analysis/typeComplexityAnalysis';
 import { RateLimiterOptions, RateLimiterSelection } from '../@types/rateLimit';
 import { TypeWeightConfig } from '../@types/buildTypeWeights';
+import { connect } from '../utils/redis';
 
 // FIXME: Will the developer be responsible for first parsing the schema from a file?
 // Can consider accepting a string representing a the filepath to a schema
@@ -40,7 +41,9 @@ export function expressRateLimiter(
     // TODO: Throw ValidationError if schema is invalid
     const typeWeightObject = buildTypeWeightsFromSchema(schema, typeWeightConfig);
     // TODO: Throw error if connection is unsuccessful
-    const redisClient = new Redis(redisClientOptions); // Default port is 6379 automatically
+    // Default connection timeout is 10000 ms of inactivity
+    // FIXME: Do we need to re-establish connection?
+    const redisClient = connect(redisClientOptions); // Default port is 6379 automatically
     const rateLimiter = setupRateLimiter(rateLimiterAlgo, rateLimiterOptions, redisClient);
 
     // return the rate limiting middleware
@@ -66,7 +69,7 @@ export function expressRateLimiter(
          * req.ip and req.ips will worx in express but not with other frameworks
          */
         // check for a proxied ip address before using the ip address on request
-        const ip: string = req.ips[0] || req.ip;
+        const ip: string = req.ips ? req.ips[0] : req.ip;
 
         // FIXME: this will only work with type complexity
         const queryAST = parse(query);
@@ -80,8 +83,8 @@ export function expressRateLimiter(
 
         const queryComplexity = getQueryTypeComplexity(queryAST, variables, typeWeightObject);
         try {
-            // process the request and conditinoally respond to client with status code 429 o
-            // r pass the request onto the next middleware function
+            // process the request and conditinoally respond to client with status code 429 or
+            // pass the request onto the next middleware function
             const rateLimiterResponse = await rateLimiter.processRequest(
                 ip,
                 requestTimestamp,

src/rateLimiters/tokenBucket.ts

@@ -51,7 +51,7 @@ class TokenBucket implements RateLimiter {
         const bucketJSON = await this.client.get(uuid);
 
         // if the response is null, we need to create a bucket for the user
-        if (bucketJSON === null) {
+        if (!bucketJSON) {
             const newUserBucket: RedisBucket = {
                 // conditionally set tokens depending on how many are requested comapred to the capacity
                 tokens: tokens > this.capacity ? this.capacity : this.capacity - tokens,

src/utils/__mocks__/redis.ts

@@ -0,0 +1,23 @@
+import Redis from 'ioredis';
+
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const RedisMock = require('ioredis-mock');
+
+const clients: Redis[] = [];
+
+/**
+ * Connects to a client returning the client and a spe
+ * @param options
+ */
+export function connect(): Redis {
+    const client = new RedisMock();
+    clients.push(client);
+    return client;
+}
+
+/**
+ * Shutsdown all redis client connections
+ */
+export async function shutdown(): Promise<'OK'[]> {
+    return Promise.all(clients.map((client: Redis) => client.quit()));
+}

src/utils/redis.ts

@@ -0,0 +1,24 @@
+import Redis, { RedisOptions } from 'ioredis';
+
+const clients: Redis[] = [];
+
+/**
+ * Connects to a client returning the client and a spe
+ * @param options
+ */
+export function connect(options: RedisOptions): Redis {
+    // TODO: Figure out what other options we should set (timeouts, etc)
+    // TODO: pass on connection error
+    const client: Redis = new Redis(options);
+    clients.push(client);
+    return client;
+}
+
+/**
+ * Shutsdown all redis client connections
+ */
+export async function shutdown(): Promise<'OK'[]> {
+    // TODO: Add functinoality to shutdown a client by an id
+    // TODO: Error handling
+    return Promise.all(clients.map((client: Redis) => client.quit()));
+}