Clear up remaining truthiness issues.

CHANGELOG.md

@@ -15,9 +15,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 - Organized default metrics
 - perf: Histogram rendering builds its export list straight from the store iterator instead of an intermediate array. Faster at high series counts on Node 24 and 26, can be slightly slower on Node 22
 - fix: Correct content type exported for cluster and worker mode.
-- perf: Remove truthy conditionals from default metric collectors
+- perf: Remove truthy conditionals from the codebase
 - fix: Preserve zero-valued Counter exemplars
-- perf: Remove object and array fallback truthiness from core metric paths
 
 ### Added
 

lib/cluster.js

@@ -347,7 +347,7 @@ async function primaryListener(worker, event) {
 		}
 		request.responseHandlers.delete(worker.id);
 
-		if (event.error) {
+		if (event.error !== undefined) {
 			response.reject(new Error(event.error));
 		} else {
 			response.resolve({
@@ -409,8 +409,7 @@ function scanListeners(messageType, emitter, fn) {
 	const functionString = fn.toString();
 
 	for (const listener of emitter.listeners(messageType)) {
-		// eslint-disable-next-line eqeqeq
-		if (functionString == listener) {
+		if (functionString === `${listener}`) {
 			if (['test', 'development'].includes(process.env.NODE_ENV)) {
 				debug('removing duplicate listener', messageType);
 				emitter.off(messageType, listener);

lib/counter.js

@@ -109,7 +109,7 @@ class Counter extends Metric {
 	}
 
 	async get() {
-		if (this.collect) {
+		if (this.collect !== undefined) {
 			const v = this.collect();
 			if (v instanceof Promise) await v;
 		}

lib/gauge.js

@@ -110,7 +110,7 @@ class Gauge extends Metric {
 	}
 
 	async get() {
-		if (this.collect) {
+		if (this.collect !== undefined) {
 			const v = this.collect();
 			if (v instanceof Promise) await v;
 		}

lib/histogram.js

@@ -116,7 +116,7 @@ class Histogram extends Metric {
 	}
 
 	async getForPromString() {
-		if (this.collect) {
+		if (this.collect !== undefined) {
 			const v = this.collect();
 			if (v instanceof Promise) await v;
 		}

lib/metric.js

@@ -37,10 +37,10 @@ class Metric {
 			defaults,
 			config,
 		);
-		if (!this.registers) {
-			// in case config.registers is `undefined`
-			this.registers = [Registry.globalRegistry];
-		}
+
+		// in case config.registers is `undefined`
+		this.registers ??= [Registry.globalRegistry];
+
 		if (!this.help) {
 			throw new Error('Missing mandatory help parameter');
 		}

lib/pushgateway.js

@@ -108,10 +108,7 @@ async function useGateway(method, job, groupings) {
 			this.registry
 				.metrics()
 				.then(metrics => {
-					if (
-						options.headers &&
-						options.headers['Content-Encoding'] === 'gzip'
-					) {
+					if (options.headers?.['Content-Encoding'] === 'gzip') {
 						metrics = gzipSync(metrics);
 					}
 					req.write(metrics);

lib/registry.js

@@ -110,12 +110,12 @@ class Registry {
 				val.value,
 			)}`;
 
-			const { exemplar } = val;
-			if (exemplar && isOpenMetrics) {
-				const formattedExemplars = formatLabels(exemplar.labelSet);
-				fullMetricLine += ` # {${formattedExemplars.join(
-					',',
-				)}} ${getValueAsString(exemplar.value)} ${exemplar.timestamp}`;
+			if (isOpenMetrics) {
+				const { exemplar } = val;
+				if (exemplar) {
+					const formattedExemplars = formatLabels(exemplar.labelSet).join(',');
+					fullMetricLine += ` # {${formattedExemplars}} ${getValueAsString(exemplar.value)} ${exemplar.timestamp}`;
+				}
 			}
 			values.push(fullMetricLine);
 		}

lib/timeWindowQuantiles.js

@@ -18,8 +18,8 @@ const { TDigest } = require('tdigest');
 
 class TimeWindowQuantiles {
 	constructor(maxAgeSeconds, ageBuckets) {
-		this.maxAgeSeconds = maxAgeSeconds || 0;
-		this.ageBuckets = ageBuckets || 0;
+		this.maxAgeSeconds = maxAgeSeconds ?? 0;
+		this.ageBuckets = ageBuckets ?? 0;
 
 		this.shouldRotate = maxAgeSeconds && ageBuckets;
 

lib/util.js

@@ -134,7 +134,7 @@ function hashObject(labels, labelNames) {
 	// is unique for each possible labels object and consistent across
 	// calls with equivalent labels objects.
 
-	if (labelNames) {
+	if (labelNames !== undefined) {
 		return fastHashObject(labelNames, labels);
 	}
 

test/clusterTest.js

@@ -342,7 +342,7 @@ describe.each([
 			} finally {
 				jest.dontMock('cluster');
 				gauge.remove();
-				if (connectedDescriptor) {
+				if (connectedDescriptor !== undefined) {
 					Object.defineProperty(process, 'connected', connectedDescriptor);
 				} else {
 					delete process.connected;
@@ -418,7 +418,7 @@ describe('worker message handling', () => {
 			jest.resetModules();
 			jest.dontMock('cluster');
 			process.removeListener('message', listener);
-			if (connectedDescriptor) {
+			if (connectedDescriptor !== undefined) {
 				Object.defineProperty(process, 'connected', connectedDescriptor);
 			} else {
 				delete process.connected;

test/defaultMetricsTest.js

@@ -27,7 +27,7 @@ describe.each([
 	beforeAll(() => {
 		cpuUsage = process.cpuUsage;
 
-		if (cpuUsage) {
+		if (cpuUsage !== undefined) {
 			Object.defineProperty(process, 'cpuUsage', {
 				value() {
 					return { user: 1000, system: 10 };
@@ -43,7 +43,7 @@ describe.each([
 	});
 
 	afterAll(() => {
-		if (cpuUsage) {
+		if (cpuUsage !== undefined) {
 			Object.defineProperty(process, 'cpuUsage', {
 				value: cpuUsage,
 			});

test/exemplarsTest.js

@@ -280,17 +280,18 @@ describe('Exemplars', () => {
 				});
 			});
 
-			function getValueByLabel(label, values, key) {
+			function getValueByLabel(label, values, key = 'le') {
 				return values.reduce((acc, val) => {
-					if (val.labels && val.labels[key || 'le'] === label) {
+					if (val.labels?.[key] === label) {
 						acc = val;
 					}
 					return acc;
 				}, {});
 			}
-			function getValuesByLabel(label, values, key) {
+
+			function getValuesByLabel(label, values, key = 'le') {
 				return values.reduce((acc, val) => {
-					if (val.labels && val.labels[key || 'le'] === label) {
+					if (val.labels?.[key] === label) {
 						acc.push(val);
 					}
 					return acc;

test/histogramTest.js

@@ -503,17 +503,17 @@ describe.each([
 			return acc;
 		}, {});
 	}
-	function getValueByLabel(label, values, key) {
+	function getValueByLabel(label, values, key = 'le') {
 		return values.reduce((acc, val) => {
-			if (val.labels && val.labels[key || 'le'] === label) {
+			if (val.labels?.[key] === label) {
 				acc = val;
 			}
 			return acc;
 		}, {});
 	}
-	function getValuesByLabel(label, values, key) {
+	function getValuesByLabel(label, values, key = 'le') {
 		return values.reduce((acc, val) => {
-			if (val.labels && val.labels[key || 'le'] === label) {
+			if (val.labels?.[key] === label) {
 				acc.push(val);
 			}
 			return acc;

test/metrics/gcTest.js

@@ -50,7 +50,7 @@ describe.each([
 			// node version is too old
 		}
 
-		if (perf_hooks) {
+		if (perf_hooks !== undefined) {
 			expect(metrics).toHaveLength(1);
 
 			expect(metrics[0].help).toEqual(