Await pending promise from ratelimit result

b2ba537 didn't actually fix the problem of the hanging lambdas. It just
masked the issue by not being applied to GET requests.

By awaiting the pending promise, also the POST invocations are finished
properly.

In addition, and unrelated, we're switching from a sliding to a fixed
window.

Author: unstubbable

src/handler/ratelimit-middleware.ts

@@ -2,8 +2,25 @@ import {Ratelimit} from '@upstash/ratelimit';
 import {Redis} from '@upstash/redis';
 import type {MiddlewareHandler} from 'hono';
 
+let ratelimit: Ratelimit;
+
+try {
+  ratelimit = new Ratelimit({
+    redis: Redis.fromEnv(),
+    limiter: Ratelimit.fixedWindow(10, `10 m`),
+  });
+} catch (error) {
+  if (process.env.UPSTASH_REDIS_REST_URL) {
+    console.error(error);
+  } else {
+    console.warn(
+      `Unable to create Redis instance, no rate limits are applied.`,
+    );
+  }
+}
+
 export const ratelimitMiddleware: MiddlewareHandler = async (context, next) => {
-  if (context.req.method !== `POST`) {
+  if (!ratelimit || context.req.method !== `POST`) {
     return next();
   }
 
@@ -16,14 +33,9 @@ export const ratelimitMiddleware: MiddlewareHandler = async (context, next) => {
   }
 
   try {
-    const ratelimit = new Ratelimit({
-      redis: Redis.fromEnv(),
-      limiter: Ratelimit.slidingWindow(10, `10 m`),
-      analytics: true,
-    });
-
-    const {success, reset, remaining} = await ratelimit.limit(address);
+    const {success, reset, remaining, pending} = await ratelimit.limit(address);
     console.debug(`Rate limit result`, {address, success, remaining});
+    await pending;
 
     if (!success) {
       console.warn(`Too Many Requests by ${address}`);
@@ -33,13 +45,7 @@ export const ratelimitMiddleware: MiddlewareHandler = async (context, next) => {
       });
     }
   } catch (error) {
-    if (process.env.UPSTASH_REDIS_REST_URL) {
-      console.error(error);
-    } else {
-      console.warn(
-        `Unable to create Redis instance, no rate limits are applied.`,
-      );
-    }
+    console.error(error);
   }
 
   return next();