@flarelabs-net/workers-observability-utils/dist/metrics.test.js

A collection of Utilities for Capturing Logs and Metrics from Cloudflare Workers

import { describe, it, expect, beforeEach, beforeAll, afterAll, } from "vitest";
import { subscribe, unsubscribe } from "node:diagnostics_channel";
import { metrics } from "./index";
import { MetricType, METRICS_CHANNEL_NAME, } from "./types";
describe("metrics", () => {
    let receivedMessages = [];
    const subscriber = (message) => {
        receivedMessages.push(message);
    };
    beforeAll(() => {
        subscribe(METRICS_CHANNEL_NAME, subscriber);
    });
    beforeEach(() => {
        receivedMessages = [];
    });
    afterAll(() => {
        unsubscribe(METRICS_CHANNEL_NAME, subscriber);
    });
    describe("count", () => {
        it("should publish count metric with custom value and tags", () => {
            metrics.count("test.counter", 5, { service: "api", version: 1 });
            expect(receivedMessages).toHaveLength(1);
            expect(receivedMessages[0]).toEqual({
                type: MetricType.COUNT,
                name: "test.counter",
                value: 5,
                tags: { service: "api", version: 1 },
            });
        });
    });
    describe("gauge", () => {
        it("should publish gauge metric with tags", () => {
            metrics.gauge("test.gauge", 100, { region: "us-east-1", active: true });
            expect(receivedMessages).toHaveLength(1);
            expect(receivedMessages[0]).toEqual({
                type: MetricType.GAUGE,
                name: "test.gauge",
                value: 100,
                tags: { region: "us-east-1", active: true },
            });
        });
    });
    describe("histogram", () => {
        it("should publish histogram metric with options and tags", () => {
            const options = {
                aggregates: ["max", "min", "avg"],
                percentiles: [0.5, 0.95, 0.99],
            };
            metrics.histogram("test.histogram", 150, options, { endpoint: "/api/users" });
            expect(receivedMessages).toHaveLength(1);
            expect(receivedMessages[0]).toEqual({
                type: MetricType.HISTOGRAM,
                name: "test.histogram",
                value: 150,
                tags: { endpoint: "/api/users" },
                options,
            });
        });
    });
});