fix(data): keep future/undated news out of historical windows

The yfinance news date filter only ran when an article had a parsed date, so
flat-format and undated articles bypassed it and leaked future news into
historical/backtest runs. Parse the flat providerPublishTime, apply one
look-ahead-safe window rule across ticker and global news (undated kept only
when the window reaches the present), and return an informative message when
everything is filtered out.

tests/test_news_lookahead.py

@@ -0,0 +1,80 @@
+"""yfinance news must not leak future-dated (or undated, in a backtest) articles
+into a historical window.
+
+Regressions for #992 (flat articles bypassed the date filter), #1007 (global
+news injected future articles), #993 (empty-after-filter returned a blank body).
+"""
+import time
+from datetime import datetime
+from unittest import mock
+
+import pytest
+
+import tradingagents.dataflows.yfinance_news as ynews
+
+
+def _epoch(date_str):
+    return int(time.mktime(datetime.strptime(date_str, "%Y-%m-%d").timetuple()))
+
+
+@pytest.mark.unit
+def test_flat_article_publish_time_is_parsed():
+    # #992: flat articles now carry a pub_date (was always None -> unfilterable).
+    data = ynews._extract_article_data(
+        {"title": "X", "publisher": "P", "link": "l", "providerPublishTime": _epoch("2025-05-09")}
+    )
+    assert data["pub_date"] is not None
+    assert data["pub_date"].strftime("%Y-%m-%d") == "2025-05-09"
+
+
+@pytest.mark.unit
+def test_window_excludes_future_and_undated_in_backtest():
+    start = datetime(2025, 5, 1)
+    end = datetime(2025, 5, 9)  # historical window (well in the past)
+    inside = datetime(2025, 5, 5)
+    future = datetime(2025, 6, 1)
+    assert ynews._in_news_window(inside, start, end) is True
+    assert ynews._in_news_window(future, start, end) is False     # look-ahead blocked
+    assert ynews._in_news_window(None, start, end) is False        # undated -> excluded in backtest
+
+
+@pytest.mark.unit
+def test_window_keeps_undated_in_live_window():
+    # Live window (reaches today): undated articles can't be "future", so keep them.
+    start = datetime.now()
+    end = datetime.now()
+    assert ynews._in_news_window(None, start, end) is True
+
+
+@pytest.mark.unit
+def test_global_news_future_flat_article_excluded(monkeypatch):
+    # #1007: a flat, future-dated global article must not appear in a historical run.
+    future_article = {"title": "FUTURE EVENT", "publisher": "P", "link": "l",
+                      "providerPublishTime": _epoch("2025-06-01")}
+    past_article = {"title": "PAST EVENT", "publisher": "P", "link": "l",
+                    "providerPublishTime": _epoch("2025-05-05")}
+
+    class FakeSearch:
+        def __init__(self, *a, **k):
+            self.news = [future_article, past_article]
+
+    monkeypatch.setattr(ynews.yf, "Search", FakeSearch)
+    out = ynews.get_global_news_yfinance("2025-05-09", look_back_days=7, limit=10)
+    assert "PAST EVENT" in out
+    assert "FUTURE EVENT" not in out  # #1007
+
+
+@pytest.mark.unit
+def test_global_news_empty_after_filter_is_informative(monkeypatch):
+    # #993: everything filtered out -> a clear message, not a blank-bodied report.
+    only_future = {"title": "FUTURE", "publisher": "P", "link": "l",
+                   "providerPublishTime": _epoch("2025-06-01")}
+
+    class FakeSearch:
+        def __init__(self, *a, **k):
+            self.news = [only_future]
+
+    monkeypatch.setattr(ynews.yf, "Search", FakeSearch)
+    out = ynews.get_global_news_yfinance("2025-05-09", look_back_days=7, limit=10)
+    assert "No global news found" in out
+    assert "###" not in out  # no empty article body

tradingagents/dataflows/yfinance_news.py

@@ -41,16 +41,39 @@ def _extract_article_data(article: dict) -> dict:
             "pub_date": pub_date,
         }
     else:
-        # Fallback for flat structure
+        # Fallback for flat structure. Parse the epoch publish time so flat
+        # articles are date-filterable too (otherwise they bypass the
+        # historical window and leak future news, #992/#1007).
+        pub_date = None
+        ts = article.get("providerPublishTime")
+        if ts:
+            try:
+                pub_date = datetime.fromtimestamp(ts)
+            except (ValueError, OSError, TypeError):
+                pass
         return {
             "title": article.get("title", "No title"),
             "summary": article.get("summary", ""),
             "publisher": article.get("publisher", "Unknown"),
             "link": article.get("link", ""),
-            "pub_date": None,
+            "pub_date": pub_date,
         }
 
 
+def _in_news_window(pub_date, start_dt, end_dt) -> bool:
+    """Whether an article belongs in the [start_dt, end_dt] window.
+
+    Dated articles are kept only if they fall in the window. An undated article
+    is kept only when the window reaches the present (live run) — in a
+    historical/backtest window it's excluded, since we can't prove it isn't
+    future news (look-ahead safety, #992/#1007).
+    """
+    if pub_date is not None:
+        naive = pub_date.replace(tzinfo=None) if hasattr(pub_date, "replace") else pub_date
+        return start_dt <= naive <= end_dt + relativedelta(days=1)
+    return end_dt >= datetime.now() - relativedelta(days=1)
+
+
 def get_news_yfinance(
     ticker: str,
     start_date: str,
@@ -85,10 +108,8 @@ def get_news_yfinance(
         for article in news:
             data = _extract_article_data(article)
 
-            # Filter by date if publish time is available
-            if data["pub_date"]:
-                pub_date_naive = data["pub_date"].replace(tzinfo=None)
-                if not (start_dt <= pub_date_naive <= end_dt + relativedelta(days=1)):
+            # Keep only articles within the requested window (look-ahead safe).
+            if not _in_news_window(data["pub_date"], start_dt, end_dt):
                 continue
 
             news_str += f"### {data['title']} (source: {data['publisher']})\n"
@@ -170,31 +191,25 @@ def get_global_news_yfinance(
         start_date = start_dt.strftime("%Y-%m-%d")
 
         news_str = ""
+        kept = 0
         for article in all_news[:limit]:
-            # Handle both flat and nested structures
-            if "content" in article:
+            # Extract uniformly (flat + nested) and apply the same look-ahead-safe
+            # window filter, so flat articles can't leak future news (#1007).
             data = _extract_article_data(article)
-                # Skip articles published after curr_date (look-ahead guard)
-                if data.get("pub_date"):
-                    pub_naive = data["pub_date"].replace(tzinfo=None) if hasattr(data["pub_date"], "replace") else data["pub_date"]
-                    if pub_naive > curr_dt + relativedelta(days=1):
+            if not _in_news_window(data["pub_date"], start_dt, curr_dt):
                 continue
-                title = data["title"]
-                publisher = data["publisher"]
-                link = data["link"]
-                summary = data["summary"]
-            else:
-                title = article.get("title", "No title")
-                publisher = article.get("publisher", "Unknown")
-                link = article.get("link", "")
-                summary = ""
-
-            news_str += f"### {title} (source: {publisher})\n"
-            if summary:
-                news_str += f"{summary}\n"
-            if link:
-                news_str += f"Link: {link}\n"
+            news_str += f"### {data['title']} (source: {data['publisher']})\n"
+            if data["summary"]:
+                news_str += f"{data['summary']}\n"
+            if data["link"]:
+                news_str += f"Link: {data['link']}\n"
             news_str += "\n"
+            kept += 1
+
+        # All candidates fell outside the window -> say so rather than return an
+        # empty-bodied report (#993).
+        if kept == 0:
+            return f"No global news found between {start_date} and {curr_date}"
 
         return f"## Global Market News, from {start_date} to {curr_date}:\n\n{news_str}"