korting/test/checkProducts.test.js

const test = require('node:test');
const assert = require('node:assert/strict');
const { checkProduct, checkAllProducts } = require('../src/checkProducts');

function makeDeps(overrides = {}) {
  const failures = [];
  const successes = [];
  const mailCalls = [];
  const deps = {
    fetchAndExtractPrice: async () => ({ price: 10, method: 'meta', error: null }),
    sendMail: async (payload) => { mailCalls.push(payload); },
    recordCheckFailure: (id, status) => failures.push({ id, status }),
    recordCheckSuccess: (id, data) => successes.push({ id, ...data }),
    now: () => '2026-09-05T08:00:00.000Z',
    ...overrides,
  };
  return { deps, failures, successes, mailCalls };
}

// Failure paths log to stderr; capture it so the test output stays clean
// while still proving the logging happened.
function captureErrorLog(t) {
  const logged = [];
  t.mock.method(console, 'error', (...args) => { logged.push(args.join(' ')); });
  return logged;
}

test('checkProduct stores baseline price without sending mail', async () => {
  const { deps, successes, mailCalls } = makeDeps();
  const product = { id: 1, name: 'X', url: 'https://x', last_price: null };
  const result = await checkProduct(product, deps);
  assert.equal(result.status, 'ok');
  assert.equal(result.changed, false);
  assert.equal(mailCalls.length, 0);
  assert.deepEqual(successes, [{ id: 1, price: 10, checkedAt: '2026-09-05T08:00:00.000Z' }]);
});

test('checkProduct sends mail and updates price when price changed', async () => {
  const { deps, successes, mailCalls } = makeDeps();
  const product = { id: 2, name: 'X', url: 'https://x', last_price: 15 };
  const result = await checkProduct(product, deps);
  assert.equal(result.status, 'ok');
  assert.equal(result.changed, true);
  assert.equal(mailCalls.length, 1);
  assert.deepEqual(mailCalls[0], { name: 'X', url: 'https://x', oldPrice: 15, newPrice: 10 });
  assert.equal(successes.length, 1);
});

test('checkProduct does not send mail or update when price unchanged', async () => {
  const { deps, successes, mailCalls } = makeDeps();
  const product = { id: 3, name: 'X', url: 'https://x', last_price: 10 };
  const result = await checkProduct(product, deps);
  assert.equal(result.status, 'ok');
  assert.equal(result.changed, false);
  assert.equal(mailCalls.length, 0);
  assert.equal(successes.length, 1);
});

test('checkProduct records fetch_error and does not touch price on network failure', async (t) => {
  const logged = captureErrorLog(t);
  const { deps, failures, successes } = makeDeps({
    fetchAndExtractPrice: async () => ({ price: null, method: null, error: new Error('down') }),
  });
  const product = { id: 4, name: 'X', url: 'https://x', last_price: 10 };
  const result = await checkProduct(product, deps);
  assert.equal(result.status, 'fetch_error');
  assert.deepEqual(failures, [{ id: 4, status: 'fetch_error' }]);
  assert.equal(successes.length, 0);
  assert.equal(logged.length, 1);
  assert.match(logged[0], /fetch_error.*https:\/\/x.*down/);
});

test('checkProduct records not_found when no price could be extracted', async (t) => {
  const logged = captureErrorLog(t);
  const { deps, failures, successes } = makeDeps({
    fetchAndExtractPrice: async () => ({ price: null, method: null, error: null }),
  });
  const product = { id: 5, name: 'X', url: 'https://x', last_price: 10 };
  const result = await checkProduct(product, deps);
  assert.equal(result.status, 'not_found');
  assert.deepEqual(failures, [{ id: 5, status: 'not_found' }]);
  assert.equal(successes.length, 0);
  assert.equal(logged.length, 1);
  assert.match(logged[0], /not_found.*https:\/\/x/);
});

test('checkProduct records mail_error and keeps old price when sending mail fails', async (t) => {
  const logged = captureErrorLog(t);
  const { deps, failures, successes } = makeDeps({
    sendMail: async () => { throw new Error('smtp down'); },
  });
  const product = { id: 6, name: 'X', url: 'https://x', last_price: 15 };
  const result = await checkProduct(product, deps);
  assert.equal(result.status, 'mail_error');
  assert.deepEqual(failures, [{ id: 6, status: 'mail_error' }]);
  assert.equal(successes.length, 0);
  assert.equal(logged.length, 1);
  assert.match(logged[0], /mail_error.*https:\/\/x.*smtp down/);
});

test('checkAllProducts processes every product independently, isolating failures', async (t) => {
  captureErrorLog(t);
  const { deps } = makeDeps();
  let calls = 0;
  const throwingDeps = {
    ...deps,
    fetchAndExtractPrice: async () => {
      calls += 1;
      if (calls === 1) throw new Error('boom');
      return { price: 10, method: 'meta', error: null };
    },
  };
  const products = [
    { id: 1, name: 'A', url: 'https://a', last_price: null },
    { id: 2, name: 'B', url: 'https://b', last_price: null },
  ];
  const results = await checkAllProducts(products, throwingDeps);
  assert.equal(results.length, 2);
  assert.equal(results[0].status, 'error');
  assert.equal(results[1].status, 'ok');
});