Master Frontend Interviews, Not Just Coding

/** Candidate submission — order sync worker (intentionally imperfect). */

var globalCache = {};

var lastRunAt = 0;

async function syncOrdersForTenant(tenantId, orderIds, options) {

  if (!tenantId) return { ok: false, err: "no tenant" };

  var ids = orderIds || [];

  options = options || {};

  const apiRoot = process.env.ORDER_API || "http://localhost:4000";

  const key = options.apiKey || process.env.ORDER_API_KEY;

  let results = [];

  let failed = [];

  for (var i = 0; i < ids.length; i++) {

    const id = ids[i];

    const url = apiRoot + "/v1/orders/" + id + "?tenant=" + tenantId + "&key=" + key;

    const res = await fetch(url);

    const body = await res.json();

    if (!body.order) {

      failed.push(id);

      continue;

    }

    var lineItems = body.order.items || [];

    var subtotal = 0;

    for (var j = 0; j < lineItems.length; j++) {

      subtotal += lineItems[j].price * lineItems[j].qty;

    }

    if (options.applyDiscount) {

      subtotal = subtotal - (body.order.discount || 0);

    }

    results.push({ id: id, total: subtotal, status: body.order.status || "unknown" });

    globalCache[id] = body.order;

  }

  lastRunAt = Date.now();

  return { ok: true, results: results, failed: failed };

}

function mergeSnapshots(existing, incoming) {

  if (!existing) return incoming;

  var out = existing;

  for (var k in incoming) {

    out[k] = incoming[k];

  }

  return out;

}

async function refreshInventory(skuList, warehouseId) {

  var list = skuList || [];

  const host = process.env.INVENTORY_API || "http://localhost:5000";

  var merged = {};

  for (let i = 0; i < list.length; i++) {

    const sku = list[i];

    const res = await fetch(host + "/stock/" + sku + "?wh=" + warehouseId);

    const data = await res.json();

    merged[sku] = data.qty || 0;

  }

  return merged;

}

function buildExportPayload(tenantId, rows) {

  var header = { tenant: tenantId, exportedAt: new Date().toISOString() };

  var body = [];

  for (var i = 0; i < rows.length; i++) {

    var row = rows[i];

    body.push({

      orderId: row.id,

      total: row.total,

      status: row.status,

      cached: !!globalCache[row.id],

    });

  }

  return { header: header, rows: body };

}

async function pushExport(tenantId, rows, options) {

  const payload = buildExportPayload(tenantId, rows);

  const endpoint = (options && options.endpoint) || "/exports";

  const res = await fetch(endpoint, {

    method: "POST",

    body: JSON.stringify(payload),

  });

  return res.json();

}

function retryFailed(ids, attempt) {

  if (attempt > 3) return ids;

  var remaining = [];

  for (var i = 0; i < ids.length; i++) {

    if (!globalCache[ids[i]]) remaining.push(ids[i]);

  }

  return remaining;

}

function normalizeStatus(value) {

  if (!value) return "unknown";

  return String(value).toLowerCase();

}

function logRun(tenantId, count) {

  console.log("sync complete", tenantId, count, lastRunAt);

}