azon_seeker/scripts/test-amazon-search-pagination.ts

import { JSDOM } from 'jsdom';
import {
  collectAmazonCurrentPage,
  collectAmazonNextPageUrl,
} from '../src/page-worker/web-injectors/amazon-search-pagination';

const withDom = async <T>(url: string, html: string, callback: () => T | Promise<T>) => {
  const dom = new JSDOM(html, { url });
  const previousDocument = globalThis.document;
  const previousWindow = globalThis.window;
  Object.assign(globalThis, { document: dom.window.document, window: dom.window });
  try {
    return await callback();
  } finally {
    Object.assign(globalThis, { document: previousDocument, window: previousWindow });
    dom.window.close();
  }
};

const testNextPage = async (name: string, html: string, expected: string | null) => {
  const actual = await withDom(
    'https://www.amazon.com/s?k=security+camera&page=1',
    html,
    collectAmazonNextPageUrl,
  );
  if (actual !== expected) throw new Error(`${name}: expected ${expected}, received ${actual}`);
};

const testCurrentPage = async (name: string, url: string, html: string, expected: number) => {
  const actual = await withDom(url, html, collectAmazonCurrentPage);
  if (actual !== expected) throw new Error(`${name}: expected ${expected}, received ${actual}`);
};

const main = async () => {
  await testNextPage(
    'active next page',
    '<a class="s-pagination-next" href="/s?k=security+camera&page=2">Next</a>',
    'https://www.amazon.com/s?k=security+camera&page=2',
  );
  await testNextPage(
    'disabled next page',
    '<span class="s-pagination-next s-pagination-disabled">Next</span>',
    null,
  );
  await testNextPage('missing next page', '<main>No pagination</main>', null);
  await testCurrentPage(
    'URL page wins over stale pagination selection',
    'https://www.amazon.com/s?k=home+security&page=11&ref=sr_pg_11',
    '<span class="s-pagination-item s-pagination-selected">12</span>',
    11,
  );
  for (const page of [1, 2, 5, 10, 20]) {
    await testCurrentPage(
      `URL page ${page}`,
      `https://www.amazon.com/s?k=home+security&page=${page}&ref=sr_pg_${page}`,
      `<span class="s-pagination-item s-pagination-selected">${page + 1}</span>`,
      page,
    );
  }
  await testCurrentPage(
    'invalid URL page uses ref fallback',
    'https://www.amazon.com/s?k=home+security&page=invalid&ref=sr_pg_9',
    '<span class="s-pagination-item s-pagination-selected">10</span>',
    9,
  );
  await testCurrentPage(
    'ref page fallback',
    'https://www.amazon.com/s?k=home+security&ref=sr_pg_7',
    '<main>No selected pagination item</main>',
    7,
  );
  await testCurrentPage(
    'selected pagination fallback',
    'https://www.amazon.com/s?k=home+security',
    '<span class="s-pagination-item s-pagination-selected">5</span>',
    5,
  );
  await testCurrentPage(
    'first page fallback',
    'https://www.amazon.com/s?k=home+security',
    '<main>No pagination</main>',
    1,
  );
  console.log('Amazon search pagination tests passed.');
};

void main();