Issue #35 limiter is not working - sample with promise

samples/rateLimitPromise.js

@@ -0,0 +1,71 @@
+console.log(' ### Sample - rateLimiter with promise')
+
+var RateLimiter = require('../index.js').RateLimiter;
+// from outside the module, you have to use:
+// var RateLimiter = require('limiter').RateLimiter;
+
+const MAX_PER_SECONDS=10;
+
+console.log(`new RateLimiter(${MAX_PER_SECONDS}, 'second')`)
+const limiter = new RateLimiter(MAX_PER_SECONDS, 'second');
+
+var nbDoneAll = 0;
+var nbDone = 0;
+
+function waitDone(nbDone, expected) {
+  do {}
+  while (nbDone<expected);
+}
+
+function businessCode(extra) {
+  nbDone++;nbDoneAll++;
+  // console.log(`${nbDone} : businessCode(${extra})`);
+  return Promise.resolve("RESULT:"+extra);
+}
+
+
+function asyncRemoveTokens(count) {// hurliman/node-rate-limiter/issues/63 by sunknudsen
+  return new Promise((resolve, reject) => {
+    limiter.removeTokens(count, (error, remainingRequests) => {
+      if (error) return reject(error)
+      resolve(remainingRequests)
+    })
+  })
+}
+
+async function limitedCallPromiseWithResult(extra) {
+  await asyncRemoveTokens(1)
+  .then((remainingRequests) => {
+    businessCode(extra)
+     .then((result)=>console.log("PromiseWithResult==>" + result));
+  })
+  .catch((limiterErr) => {
+    console.log("PromiseWithResult error==>" + limiterErr);
+  });
+}
+
+var nbDone = 0;
+const start = new Date();
+
+async function countEachSecond() {
+  if (nbDone < 0) {
+    return;
+  }
+  const duration = new Date() - start;
+  console.log(`duration: ${duration}ms => ${nbDone} / ${nbDoneAll}`)
+  nbDone = 0;
+  setTimeout(countEachSecond, 1000);
+}
+
+async function testPromise() {
+  await countEachSecond();
+  for (var i=0;i<200;i++) {
+       await limitedCallPromiseWithResult("promiseWithResult"+i);
+  }
+  const duration = new Date() - start;
+  console.log(`duration: ${duration}ms ${nbDone} / ${nbDoneAll}`);
+  nbDone = -1;
+}
+
+
+testPromise();