webdev-pipeline/tests/pagespeed-insights.test.ts

import assert from "node:assert/strict";
import test from "node:test";

import {
  buildPageSpeedRequestUrl,
  classifyPageSpeedError,
  fetchPageSpeedResult,
  normalizePageSpeedResult,
  type PageSpeedErrorType,
} from "../lib/pagespeed-insights";

const MOBILE_RAW_FIXTURE = {
  analysisUTCTimestamp: "2026-06-01T08:00:00.000Z",
  lighthouseResult: {
    finalUrl: "https://example.com/mobil",
    categories: {
      performance: { score: 0.81 },
      accessibility: { score: 0.96 },
      "best-practices": { score: 0.77 },
      seo: { score: 0.94 },
    },
    audits: {
      "first-contentful-paint": {
        title: "Erste Inhalte",
        numericValue: 2850,
        score: 0.76,
      },
      "largest-contentful-paint": {
        title: "Größtes Inhaltselement",
        numericValue: 4300,
        score: 0.6,
      },
      "cumulative-layout-shift": {
        title: "Layout-Verschiebung",
        numericValue: 0.14,
      },
      "total-blocking-time": {
        title: "Blockierende Skripte",
        numericValue: 420,
      },
      "speed-index": {
        title: "Speed Index",
        numericValue: 4800,
      },
      "unused-css-rules": {
        title: "Nicht verwendetes CSS",
        score: 0.4,
        details: {
          type: "opportunity",
          overallSavingsMs: 380,
        },
      },
      "modern-image-formats": {
        title: "Moderne Bildformate",
        score: 0.55,
        details: {
          type: "opportunity",
          overallSavingsBytes: 52000,
        },
      },
    },
  },
};

const DESKTOP_RAW_FIXTURE = {
  analysisUTCTimestamp: "2026-06-01T09:00:00.000Z",
  lighthouseResult: {
    finalUrl: "https://example.com/desktop",
    categories: {
      performance: { score: 0.93 },
      accessibility: { score: 0.99 },
      "best-practices": { score: 0.85 },
      seo: { score: 0.97 },
    },
    audits: {
      "first-contentful-paint": {
        title: "Erste Inhalte",
        numericValue: 1800,
        score: 0.91,
      },
      "largest-contentful-paint": {
        title: "Größtes Inhaltselement",
        numericValue: 3600,
        score: 0.73,
      },
      "cumulative-layout-shift": {
        title: "Layout-Verschiebung",
        numericValue: 0.08,
      },
      "total-blocking-time": {
        title: "Blockierende Skripte",
        numericValue: 310,
      },
      "speed-index": {
        title: "Speed Index",
        numericValue: 3800,
      },
      "offscreen-images": {
        title: "Außenseiten-Bilder",
        score: 0.9,
        details: {
          type: "opportunity",
          overallSavingsMs: 210,
        },
      },
    },
  },
};

test("buildPageSpeedRequestUrl includes required query params and repeated categories", () => {
  const url = buildPageSpeedRequestUrl({
    url: "https://example.com/landing?x=1&y=2",
    strategy: "mobile",
    locale: "de-DE",
    apiKey: "super-secret",
  });
  const parsed = new URL(url);

  assert.equal(
    parsed.origin + parsed.pathname,
    "https://pagespeedonline.googleapis.com/pagespeedonline/v5/runPagespeed",
  );
  assert.equal(parsed.searchParams.get("url"), "https://example.com/landing?x=1&y=2");
  assert.equal(parsed.searchParams.get("strategy"), "mobile");
  assert.equal(parsed.searchParams.get("locale"), "de-DE");
  assert.equal(parsed.searchParams.get("key"), "super-secret");
  assert.deepEqual(parsed.searchParams.getAll("category"), [
    "performance",
    "accessibility",
    "best-practices",
    "seo",
  ]);
  assert.equal(
    parsed.search.includes("url=https%3A%2F%2Fexample.com%2Flanding%3Fx%3D1%26y%3D2"),
    true,
    "URL input should be encoded",
  );
});

test("buildPageSpeedRequestUrl omits empty API keys", () => {
  const url = buildPageSpeedRequestUrl({
    url: "https://example.com",
    strategy: "desktop",
    apiKey: "",
    locale: "de-DE",
  });
  const parsed = new URL(url);
  assert.equal(parsed.searchParams.has("key"), false);
});

test("normalizePageSpeedResult maps mobile scores, metrics, and implications", () => {
  const normalized = normalizePageSpeedResult({
    strategy: "mobile",
    sourceUrl: "https://example.com",
    raw: MOBILE_RAW_FIXTURE,
  });

  assert.equal(normalized.strategy, "mobile");
  assert.equal(normalized.sourceUrl, "https://example.com");
  assert.equal(normalized.finalUrl, "https://example.com/mobil");
  assert.equal(normalized.analysisTimestamp, "2026-06-01T08:00:00.000Z");
  assert.equal(normalized.scores?.performance, 0.81);
  assert.equal(normalized.scores?.accessibility, 0.96);
  assert.equal(normalized.scores?.bestPractices, 0.77);
  assert.equal(normalized.scores?.seo, 0.94);
  assert.equal(normalized.metrics.firstContentfulPaintMs, 2850);
  assert.equal(normalized.metrics.largestContentfulPaintMs, 4300);
  assert.equal(normalized.metrics.cumulativeLayoutShift, 0.14);
  assert.equal(normalized.metrics.totalBlockingTimeMs, 420);
  assert.equal(normalized.metrics.speedIndexMs, 4800);
  assert.equal(normalized.opportunities.length >= 1, true);
  assert.equal(normalized.implications.length >= 2, true);
  assert.equal(normalized.implications.some((text) => text.includes("Besucher")), true);
  for (const implication of normalized.implications) {
    assert.equal(
      /score\s*\d+/i.test(implication),
      false,
      `Implication should not contain raw score text: ${implication}`,
    );
    assert.equal(implication.length > 0, true);
  }
});

test("normalizePageSpeedResult maps desktop scores and metrics", () => {
  const normalized = normalizePageSpeedResult({
    strategy: "desktop",
    sourceUrl: "https://example.com/landing",
    raw: DESKTOP_RAW_FIXTURE,
  });

  assert.equal(normalized.strategy, "desktop");
  assert.equal(normalized.sourceUrl, "https://example.com/landing");
  assert.equal(normalized.finalUrl, "https://example.com/desktop");
  assert.equal(normalized.analysisTimestamp, "2026-06-01T09:00:00.000Z");
  assert.equal(normalized.scores?.performance, 0.93);
  assert.equal(normalized.scores?.bestPractices, 0.85);
  assert.equal(normalized.metrics.firstContentfulPaintMs, 1800);
  assert.equal(normalized.metrics.speedIndexMs, 3800);
  assert.equal(normalized.metrics.totalBlockingTimeMs, 310);
  assert.equal(normalized.opportunities.length >= 1, true);
  assert.equal(normalized.implications.length >= 2, true);
});

test("classifyPageSpeedError maps status and body signals", () => {
  const quotaByStatus = classifyPageSpeedError({ status: 429 });
  assert.equal(quotaByStatus.errorType, "quota");

  const quotaByBody = classifyPageSpeedError({
    status: 403,
    body: { error: { errors: [{ reason: "userRateLimitExceeded" }] } },
  });
  assert.equal(quotaByBody.errorType, "quota");

  const timeoutError = classifyPageSpeedError({
    error: new DOMException("timed out", "AbortError"),
  });
  assert.equal(timeoutError.errorType, "timeout");

  const unavailableByStatus = classifyPageSpeedError({ status: 404 });
  assert.equal(unavailableByStatus.errorType, "unavailable");

  const unavailableByBody = classifyPageSpeedError({
    status: 500,
    body: { error: { message: "Failed to fetch document from given URL" } },
  });
  assert.equal(unavailableByBody.errorType, "unavailable");

  const invalidUrl = classifyPageSpeedError({
    status: 400,
    body: { error: { message: "Invalid URL: unsupported format" } },
  });
  assert.equal(invalidUrl.errorType, "invalid_url");

  const apiError = classifyPageSpeedError({
    status: 500,
    body: { error: { message: "backend down" } },
  });
  assert.equal(apiError.errorType, "api_error");
  assert.match(apiError.message, /backend down/);
});

test("classifyPageSpeedError returns unknown for non-classified cases", () => {
  const classified = classifyPageSpeedError({
    error: new Error("something odd"),
  });
  const errorType: PageSpeedErrorType = classified.errorType;
  assert.equal(errorType, "unknown");
  assert.match(classified.message, /something odd/);
});

test("fetchPageSpeedResult uses injected fetch and uses the built request URL", async () => {
  const calls: string[] = [];

  const fetchImpl = async (url: string) => {
    calls.push(url);
    return {
      ok: true,
      status: 200,
      async json() {
        return { ok: true };
      },
    } as Response;
  };

  const actual = await fetchPageSpeedResult({
    url: "https://example.com/test?tracking=true",
    strategy: "desktop",
    apiKey: "secret-key",
    fetchImpl,
  });

  assert.deepEqual(actual, { ok: true });
  assert.equal(calls.length, 1);
  const parsed = new URL(calls[0]);
  assert.equal(parsed.searchParams.get("strategy"), "desktop");
  assert.equal(parsed.searchParams.get("locale"), "de-DE");
  assert.deepEqual(
    parsed.searchParams.getAll("category"),
    ["performance", "accessibility", "best-practices", "seo"],
  );
  assert.equal(parsed.searchParams.get("key"), "secret-key");
});

test(
  "fetchPageSpeedResult throws classified api_error when response.ok response has invalid JSON",
  async () => {
    const fetchImpl = async () =>
      ({
        ok: true,
        status: 200,
        async json() {
          throw new SyntaxError("Unexpected token <");
        },
      }) as unknown as Response;

    let caughtError: unknown;
    try {
      await fetchPageSpeedResult({
        url: "https://example.com/broken-json",
        strategy: "mobile",
        fetchImpl,
      });
      assert.fail("Expected fetchPageSpeedResult to throw");
    } catch (error) {
      caughtError = error;
    }

    assert.match(String((caughtError as Error).message), /Unexpected token </i);
    assert.equal((caughtError as Error & { errorType?: string }).errorType, "api_error");
  },
);

test("fetchPageSpeedResult preserves Google API error messages", async () => {
  const fetchImpl = async () =>
    ({
      ok: false,
      status: 403,
      async json() {
        return {
          error: {
            code: 403,
            message: "API key not valid. Please pass a valid API key.",
            status: "PERMISSION_DENIED",
          },
        };
      },
    }) as unknown as Response;

  let caughtError: unknown;
  try {
    await fetchPageSpeedResult({
      url: "https://example.com/key-error",
      strategy: "desktop",
      fetchImpl,
    });
    assert.fail("Expected fetchPageSpeedResult to throw");
  } catch (error) {
    caughtError = error;
  }

  assert.equal((caughtError as Error & { errorType?: string }).errorType, "api_error");
  assert.match(String((caughtError as Error).message), /API key not valid/);
});