SDK drift: filterMarkets/filter_markets treat a market missing resolutionDate oppositely — included in TypeScript, excluded in Python #1555

Drift

When a resolutionDate filter criterion is supplied and the candidate market's resolutionDate/resolution_date is falsy/missing, TypeScript keeps the market in the result set (the guard short-circuits and no exclusion happens), while Python explicitly excludes it. Same filter criteria + same market data yields opposite inclusion decisions across languages. This is the same category of bug as already-filed #1524 (priceChange24h), but on a different field (resolutionDate) not mentioned by that or any other filed issue.

TypeScript SDK

sdks/typescript/pmxt/client.ts:2948-2957:

// ResolutionDate filter
if (criteria.resolutionDate && market.resolutionDate) {
    const resDate = market.resolutionDate;
    if (criteria.resolutionDate.before && resDate >= criteria.resolutionDate.before) {
        return false;
    }
    if (criteria.resolutionDate.after && resDate <= criteria.resolutionDate.after) {
        return false;
    }
}

criteria.resolutionDate && market.resolutionDate short-circuits when the market's date is missing — the market is not rejected and proceeds to the remaining checks.

Python SDK

sdks/python/pmxt/client.py:2108-2119:

# Resolution Date
if "resolution_date" in params:
    f = params["resolution_date"]
    val = market.resolution_date

    if not val:
         continue

    if "before" in f and val >= f["before"]: continue
    if "after" in f and val <= f["after"]: continue

if not val: continue explicitly excludes the market from the results.

Expected

Both languages should apply the same rule for markets missing a resolution date under a resolutionDate filter — either both should keep them (treat filter as inapplicable) or both should exclude them.

Impact

Callers filtering markets by resolution-date range get silently different result sets in TypeScript vs. Python whenever some markets lack a resolution date (e.g. still-open/perpetual markets).

Found by automated SDK cross-language drift audit