mintel.me/apps/web/src/domain/pageview-decision.spec.ts

import { describe, expect, it } from "vitest";
import {
  decidePageview,
  type IncomingPageviewRequest,
} from "./pageview-decision";

const humanRequest = (
  overrides: Partial<IncomingPageviewRequest> = {},
): IncomingPageviewRequest => ({
  method: "GET",
  secFetchDest: "document",
  pathname: "/",
  search: "",
  hostname: "mintel.me",
  referrer: "",
  language: "de-DE",
  userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) Chrome/131.0.0.0",
  clientIp: "84.117.2.55",
  ...overrides,
});

describe("decidePageview", () => {
  it("tracks a browser navigation for the homepage", () => {
    const decision = decidePageview(humanRequest());
    expect(decision).toEqual({
      track: true,
      facts: {
        url: "/",
        hostname: "mintel.me",
        referrer: "",
        language: "de-DE",
        userAgent: humanRequest().userAgent,
        clientIp: "84.117.2.55",
      },
    });
  });

  it("keeps the query string in the tracked url", () => {
    const decision = decidePageview(
      humanRequest({ pathname: "/imprint", search: "?from=footer" }),
    );
    expect(decision).toMatchObject({
      track: true,
      facts: { url: "/imprint?from=footer" },
    });
  });

  it("tracks a blog-style slug that merely contains a file-like segment", () => {
    const decision = decidePageview(
      humanRequest({ pathname: "/blog/next.js-vs-remix" }),
    );
    expect(decision).toMatchObject({ track: true });
  });

  it("tracks a slug that merely starts like a metadata image route", () => {
    const decision = decidePageview(
      humanRequest({ pathname: "/notes/opengraph-image-deep-dive" }),
    );
    expect(decision).toMatchObject({ track: true });
  });

  it("accepts the method in lower case", () => {
    const decision = decidePageview(humanRequest({ method: "get" }));
    expect(decision).toMatchObject({ track: true });
  });

  it.each([
    ["a form submission", { method: "POST" }],
    ["a head request", { method: "HEAD" }],
    ["an options probe", { method: "OPTIONS" }],
  ])("skips %s", (_label, overrides) => {
    const decision = decidePageview(humanRequest(overrides));
    expect(decision).toEqual({ track: false, reason: "non-get-method" });
  });

  it.each([
    ["a router prefetch payload", "empty"],
    ["a script subresource", "script"],
    ["an image subresource", "image"],
    ["a request without fetch metadata", ""],
  ])("skips %s", (_label, secFetchDest) => {
    const decision = decidePageview(humanRequest({ secFetchDest }));
    expect(decision).toEqual({
      track: false,
      reason: "non-navigation-request",
    });
  });

  it.each([
    ["a next build chunk", "/_next/static/chunks/main-abc123.js"],
    ["a next image request", "/_next/image"],
    ["a public image", "/images/portrait.webp"],
    ["a jpeg photo", "/images/photo.jpg"],
    ["a woff font", "/fonts/inter.woff"],
    ["a font", "/fonts/inter.woff2"],
    ["a feed document", "/rss.xml"],
    ["the sitemap", "/sitemap.xml"],
    ["the robots file", "/robots.txt"],
    ["the web manifest", "/manifest.webmanifest"],
    ["an open graph image route", "/opengraph-image"],
    ["a twitter image route", "/twitter-image"],
    ["a favicon", "/favicon.ico"],
  ])("skips %s at %s", (_label, pathname) => {
    const decision = decidePageview(humanRequest({ pathname }));
    expect(decision).toEqual({ track: false, reason: "static-asset" });
  });

  it.each([
    ["the analytics proxy", "/stats/api/send"],
    ["the error relay", "/errors/api/relay"],
    ["an api route", "/api/contact"],
    ["the api health check", "/api/health"],
    ["the health check", "/health"],
    ["the gatekeeper", "/gatekeeper/api/verify"],
    ["a well-known challenge", "/.well-known/acme-challenge/token"],
  ])("skips %s at %s", (_label, pathname) => {
    const decision = decidePageview(humanRequest({ pathname }));
    expect(decision).toEqual({ track: false, reason: "infrastructure-path" });
  });

  it.each([
    ["curl", "curl/8.1.2"],
    ["wget", "Wget/1.21"],
    ["python requests", "python-requests/2.31"],
    ["go http", "Go-http-client/2.0"],
    ["uptime kuma", "Uptime-Kuma/1.23.11"],
    ["a crawler", "Googlebot/2.1 (+http://www.google.com/bot.html)"],
    ["a link preview", "WhatsApp/2.23.20.0"],
  ])("skips the %s user agent", (_label, userAgent) => {
    const decision = decidePageview(humanRequest({ userAgent }));
    expect(decision).toEqual({ track: false, reason: "bot-user-agent" });
  });

  it("skips a bot even when its request looks like a navigation", () => {
    const decision = decidePageview(
      humanRequest({ userAgent: "curl/8.1.2", secFetchDest: "document" }),
    );
    expect(decision).toEqual({ track: false, reason: "bot-user-agent" });
  });
});