CHANGELOG.md

@@ -8,6 +8,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 ### Changed
 ### Added
 
+## [10.2.1] - 2017-10-27
+### Changed
+- Only resolve/reject `clusterMetrics` promise if no callback is provided
+
 ## [10.2.0] - 2017-10-16
 ### Changed
 - Don't add event listeners if cluster module is not used.
@@ -84,7 +88,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 - Creating metrics with one argument per parameter - use object literals instead.
 
 
-[Unreleased]: https://github.com/siimon/prom-client/compare/v10.2.0...HEAD
+[Unreleased]: https://github.com/siimon/prom-client/compare/v10.2.1...HEAD
+[10.2.1]: https://github.com/siimon/prom-client/compare/v10.2.0...v10.2.1
 [10.2.0]: https://github.com/siimon/prom-client/compare/v10.1.1...v10.2.0
 [10.1.1]: https://github.com/siimon/prom-client/compare/v10.1.0...v10.1.1
 [10.1.0]: https://github.com/siimon/prom-client/compare/v10.0.4...v10.1.0

lib/cluster.js

@@ -37,29 +37,31 @@ class AggregatorRegistry extends Registry {
 	clusterMetrics(callback) {
 		const requestId = requestCtr++;
 
-		callback = callback || function() {};
-
 		return new Promise((resolve, reject) => {
 			const nWorkers = Object.keys(cluster.workers).length;
 
+			function done(err, result) {
+				// Don't resolve/reject the promise if a callback is provided
+				if (typeof callback === 'function') {
+					callback(err, result);
+				} else {
+					if (err) reject(err);
+					else resolve(result);
+				}
+			}
+
 			if (nWorkers === 0) {
-				return process.nextTick(() => {
-					callback(null, '');
-					resolve('');
-				});
+				return process.nextTick(() => done(null, ''));
 			}
 
 			const request = {
 				responses: [],
 				pending: nWorkers,
-				callback,
-				resolve,
-				reject,
+				done,
 				errorTimeout: setTimeout(() => {
 					request.failed = true;
 					const err = new Error('Operation timed out.');
-					request.callback(err);
-					reject(err);
+					request.done(err);
 				}, 5000),
 				failed: false
 			};
@@ -166,8 +168,7 @@ function addListeners() {
 
 					const registry = AggregatorRegistry.aggregate(request.responses);
 					const promString = registry.metrics();
-					request.callback(null, promString);
-					request.resolve(promString);
+					request.done(null, promString);
 				}
 			}
 		});

package.json

@@ -1,6 +1,6 @@
 {
   "name": "prom-client",
-  "version": "10.2.0",
+  "version": "10.2.1",
   "description": "Client for prometheus",
   "main": "index.js",
   "files": [

test/clusterTest.js

@@ -21,27 +21,15 @@ describe('AggregatorRegistry', () => {
 		it('works properly if there are no cluster workers', done => {
 			const AggregatorRegistry = require('../lib/cluster');
 			const ar = new AggregatorRegistry();
-			let cbCalled = false;
-			let promiseResolved = false;
 			let tickElapsed = false;
 			process.nextTick(() => {
 				tickElapsed = true;
 			});
-			const maybeDone = () => {
-				if (cbCalled && promiseResolved) done();
-			};
-			const ret = ar.clusterMetrics((err, metrics) => {
-				cbCalled = true;
+			ar.clusterMetrics((err, metrics) => {
 				expect(tickElapsed).toBe(true);
 				expect(err).toBeNull();
 				expect(metrics).toEqual('');
-				maybeDone();
-			});
-			ret.then(metrics => {
-				promiseResolved = true;
-				expect(tickElapsed).toBe(true);
-				expect(metrics).toEqual('');
-				maybeDone();
+				done();
 			});
 		});
 	});