fixes #34

	will set a new item in database if ttl is -1 or less which indicates the key has been decreased after ttl has expired

index.js

@@ -91,6 +91,12 @@ function ratelimit(opts) {
           ctx.set(headers);
           return next();
         }
+        if (expires < 0) {
+          debug(`${name} is stuck. Resetting.`);
+          debug('remaining %s/%s %s', opts.max - 1, opts.max, id);
+          opts.db.set(name, opts.max - 1, 'PX', opts.duration || 3600000, 'NX');
+          return next();
+        }
         // user maxed
         headers['Retry-After'] = t;
         headers[opts.headers.remaining] = n;

package.json

@@ -5,7 +5,7 @@
     "type": "git",
     "url": "git+https://github.com/scttcper/koa-simple-ratelimit.git"
   },
-  "version": "2.1.0",
+  "version": "2.1.1",
   "keywords": [
     "koa",
     "middleware",

test/ratelimit.js

@@ -10,7 +10,7 @@ const ratelimit = require('..');
 const db = redis.createClient();
 
 describe('ratelimit middleware', () => {
-  const rateLimitDuration = 1000;
+  const rateLimitDuration = 300;
   const goodBody = 'Num times hit: ';
 
   before((done) => {
@@ -55,7 +55,7 @@ describe('ratelimit middleware', () => {
       }, rateLimitDuration);
     });
 
-    it('responds with 429 when rate limit is exceeded', (done) => {
+    it('should respond with 429 when rate limit is exceeded', (done) => {
       request(app.listen())
         .get('/')
         .expect('X-RateLimit-Remaining', '0')
@@ -74,6 +74,42 @@ describe('ratelimit middleware', () => {
     });
   });
 
+  describe('shortlimit', () => {
+    let guard;
+    let app;
+
+    const routeHitOnlyOnce = () => {
+      guard.should.be.equal(1);
+    };
+
+    beforeEach((done) => {
+      app = new Koa();
+
+      app.use(ratelimit({
+        duration: 1,
+        db: db,
+        max: 1,
+      }));
+
+      app.use((ctx, next) => {
+        guard += 1;
+        ctx.body = goodBody + guard;
+        return next();
+      });
+
+      guard = 0;
+      done();
+    });
+
+    it('should respond with 429 when rate limit is exceeded', (done) => {
+      request(app.listen())
+        .get('/')
+        .expect('X-RateLimit-Remaining', '0')
+        .expect(429)
+        .end(done);
+    });
+  });
+
   describe('limit with throw', () => {
     let guard;
     let app;