Merge pull request #2 from metrics-js/return-metric

feat: return the whole metric object from getResults()

README.md

@@ -7,7 +7,7 @@
 
 
 This module is a memory based consumer for metrics streams to be used in tests. The purpose of the module is to make writing tests and asserting metrics easier.
-It takes a metric stream generated by @metrics/client and makes the collected metrics available as an array. 
+It takes a metric stream generated by @metrics/client and makes the collected metrics available as an array.
 
 ⚠️ You should _never_ use this in produciton code, however it is very convenient when writing tests which produce metrics using [`@metrics/client`](https://metrics-js.github.io/reference/client/)
 
@@ -16,29 +16,28 @@ It takes a metric stream generated by @metrics/client and makes the collected me
 Below is a sample test showing how this could be used:
 
 ```js
-const test = require('tap');
-const Metrics = require('@metrics/client');
-const TestConsumer = require('@metrics/test-consumer');
-
-test('some test case', async () => {
-    const metrics = new Metrics();
-    // This sets up the metrics client to be used
-    const testHelper = new TestConsumer(metrics)
-    // .start sets up the stream
-    testHelper.start();
-
-    // Code which triggers a count metric
-
-    testHelper.stop(); // .stop ends the streams and now we can get the result.
-
-    testHelper.getResults().then(result => {
-        t.equal(result.name, "some_counter"); // Validate our metrics was collected
-        res.labels.forEach((metricLabel) => {
-            if (metricLabel.name === "value") {
-                t.equal(metricLabel.value, 2); // We expect two counts to have happened
-            }
-        });
-    });
+const assert = require("node:assert");
+const { test } = require("node:test");
+const MetricsClient = require("@metrics/client");
+const TestConsumer = require("@metrics/test-consumer");
+
+test("some test case", async () => {
+  // Pass in the metrics client you want to consume.
+  const metrics = new MetricsClient();
+  const testHelper = new TestConsumer(metrics);
+  // Sets up the consumer to capture events.
+  testHelper.start();
+
+  // 👋 Your code which produces some kind of metric goes here.
+
+  // Ends the streams, now we can get the result.
+  testHelper.stop();
+
+  const result = await testHelper.getResults();
+  const metric = result.find((m) => m.name === "some_counter");
+
+  assert.ok(metric, "Expected to find metric some_counter");
+  assert.equal(metric.value, 2);
 });
 ```
 

lib/index.js

@@ -59,14 +59,12 @@ class TestConsumer {
 	}
 
 	/**
-	 * Utility function returning an array of simple metric object.
-	 * @return {Promise<Array<Partial<import("@metrics/metric")>>>} list of simplified metrics
+	 * Utility function returning an array of metric objects.
+	 *
+	 * @return {Promise<Array<import("@metrics/metric")>>} list of metrics
 	 */
 	async getResults() {
-		return (await this.result).map((metric) => ({
-			name: metric.name,
-			labels: metric.labels,
-		}));
+		return await this.result;
 	}
 
 	/**

test/index.js

@@ -43,3 +43,26 @@ test("can create dummy metric for counter & timer", async (t) => {
 	const timer = createMetric.timer({ uri: "/lol2" });
 	t.equal(timer.name, "http_request_duration_seconds");
 });
+
+test("lets you get the value of a counter", async (t) => {
+	// Pass in the metrics client you want to consume.
+	const metrics = new MetricsClient();
+	const testHelper = new TestConsumer(metrics);
+	// Sets up the consumer to capture events.
+	testHelper.start();
+
+	const counter = metrics.counter({
+		name: "a_custom_counter_metric",
+		description: "A custom metric",
+	});
+	counter.inc(2, { labels: { type: "some_label" } });
+
+	// Ends the streams, now we can get the result.
+	testHelper.stop();
+
+	const result = await testHelper.getResults();
+	const metric = result.find((m) => m.name === "a_custom_counter_metric");
+
+	t.ok(metric, "Expected to find metric a_custom_counter_metric");
+	t.equal(metric.value, 2);
+});