Adding example of Summary metric

CHANGELOG.md

@@ -36,6 +36,7 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 - Expanded benchmarking code
 - new WorkerRegistry to provide equivalent support to AggregatorRegistry
+- Added example for Summary metric
 
 ## [15.1.3] - 2024-06-27
 

example/summary.js

@@ -0,0 +1,66 @@
+'use strict';
+
+// Summary
+// Single Label
+// Multiple Values
+
+const { Summary, register } = require('..');
+
+async function main() {
+	const summ = new Summary({
+		name: 'test_summary',
+		help: 'Example of summary',
+		labelNames: ['code'],
+		percentiles: [0.5, 0.9, 0.99],
+	});
+
+	summ.observe({ code: '200' }, 0.7);
+	summ.observe({ code: '200' }, 0.1);
+	summ.observe({ code: '400' }, 1.5);
+	summ.observe({ code: '500' }, 2.2);
+
+	console.log(await register.metrics());
+	/*
+	# HELP test_summary Example of summary
+	# TYPE test_summary summary
+	test_summary{quantile="0.5",code="200"} 0.4
+	test_summary{quantile="0.9",code="200"} 0.7
+	test_summary{quantile="0.99",code="200"} 0.7
+	test_summary_sum{code="200"} 0.7999999999999999
+	test_summary_count{code="200"} 2
+	test_summary{quantile="0.5",code="400"} 1.5
+	test_summary{quantile="0.9",code="400"} 1.5
+	test_summary{quantile="0.99",code="400"} 1.5
+	test_summary_sum{code="400"} 1.5
+	test_summary_count{code="400"} 1
+	test_summary{quantile="0.5",code="500"} 2.2
+	test_summary{quantile="0.9",code="500"} 2.2
+	test_summary{quantile="0.99",code="500"} 2.2
+	test_summary_sum{code="500"} 2.2
+	test_summary_count{code="500"} 1
+	*/
+
+	summ.observe({ code: '200' }, 0.4);
+	console.log(await register.metrics());
+	/*
+	# HELP test_summary Example of summary
+	# TYPE test_summary summary
+	test_summary{quantile="0.5",code="200"} 0.4
+	test_summary{quantile="0.9",code="200"} 0.7
+	test_summary{quantile="0.99",code="200"} 0.7
+	test_summary_sum{code="200"} 1.2
+	test_summary_count{code="200"} 3
+	test_summary{quantile="0.5",code="400"} 1.5
+	test_summary{quantile="0.9",code="400"} 1.5
+	test_summary{quantile="0.99",code="400"} 1.5
+	test_summary_sum{code="400"} 1.5
+	test_summary_count{code="400"} 1
+	test_summary{quantile="0.5",code="500"} 2.2
+	test_summary{quantile="0.9",code="500"} 2.2
+	test_summary{quantile="0.99",code="500"} 2.2
+	test_summary_sum{code="500"} 2.2
+	test_summary_count{code="500"} 1
+	*/
+}
+
+main();