fix: handle ValueError from parse_occurrence and add edge-case occurrence tests

- Wrap parse_occurrence() call in try/except ValueError; return skipped with reason instead of crashing
- Remove redundant `or {}` guard on sub_row (already defaulted to {} via next(..., {}))
- Strengthen test_occurrence_passes assertion to check status == "success"
- Add 3 edge-case tests: occurrence="every", missing occurrence key, invalid occurrence string

app/services/poster.py

@@ -39,8 +39,11 @@ def _run_post(db_path: str, campaign_id: int, target: str,
         sub_row = next((s for s in all_subs if s["sub"] == target), {})
 
         # Occurrence check — skip if not the right week of the month
-        occurrence_str = (sub_row or {}).get("occurrence")
+        occurrence_str = sub_row.get("occurrence")
+        try:
             parsed = parse_occurrence(occurrence_str)
+        except ValueError as exc:
+            return {"skipped": True, "reason": f"invalid occurrence {occurrence_str!r}: {exc}"}
         if parsed is not None:
             weekday, n = parsed
             if not is_nth_weekday(date.today(), weekday, n):

tests/services/test_poster.py

@@ -160,5 +160,80 @@ def test_occurrence_passes(tmp_path):
                 mock_date.today.return_value = real_date(2026, 5, 3)
                 result = _run_post(db, campaign_id=1, target="selfhosted", triggered_by="scheduler")
 
-    assert result.get("skipped") is not True
+    assert result.get("status") == "success"
     mock_strategy.execute.assert_called_once()
+
+
+def test_occurrence_every_passes_through(tmp_path):
+    """occurrence='every' means post every time — no filtering, execute is called."""
+    db = str(tmp_path / "test.db")
+    # parse_occurrence("every") returns None → no filtering → execute runs
+    mock_store = _make_store(
+        campaign_type="reddit_comment",
+        subs=[{"sub": "selfhosted", "active": 1, "occurrence": "every"}],
+    )
+    mock_result = MagicMock()
+    mock_result.url = "https://reddit.com/r/selfhosted/comments/abc/"
+
+    mock_strategy = MagicMock()
+    mock_strategy.supports_dupe_guard.return_value = False
+    mock_strategy.execute.return_value = mock_result
+
+    with patch("app.services.poster.Store", return_value=mock_store):
+        with patch("app.services.poster.get_client", return_value=mock_strategy):
+            with patch("app.services.poster.date") as mock_date:
+                from datetime import date as real_date
+                mock_date.today.return_value = real_date(2026, 5, 3)
+                result = _run_post(db, campaign_id=1, target="selfhosted", triggered_by="scheduler")
+
+    assert result.get("status") == "success"
+    mock_strategy.execute.assert_called_once()
+
+
+def test_occurrence_none_sub_row_key_passes_through(tmp_path):
+    """Sub row exists but has no occurrence key — should post normally."""
+    db = str(tmp_path / "test.db")
+    # sub_row has no "occurrence" key → .get() returns None → parse_occurrence(None) returns None
+    mock_store = _make_store(
+        campaign_type="reddit_comment",
+        subs=[{"sub": "selfhosted", "active": 1}],
+    )
+    mock_result = MagicMock()
+    mock_result.url = "https://reddit.com/r/selfhosted/comments/abc/"
+
+    mock_strategy = MagicMock()
+    mock_strategy.supports_dupe_guard.return_value = False
+    mock_strategy.execute.return_value = mock_result
+
+    with patch("app.services.poster.Store", return_value=mock_store):
+        with patch("app.services.poster.get_client", return_value=mock_strategy):
+            with patch("app.services.poster.date") as mock_date:
+                from datetime import date as real_date
+                mock_date.today.return_value = real_date(2026, 5, 3)
+                result = _run_post(db, campaign_id=1, target="selfhosted", triggered_by="scheduler")
+
+    assert result.get("status") == "success"
+    mock_strategy.execute.assert_called_once()
+
+
+def test_occurrence_invalid_string_skips(tmp_path):
+    """Malformed occurrence string results in skipped=True, not a crash."""
+    db = str(tmp_path / "test.db")
+    # "weekly" is not a valid occurrence string — parse_occurrence raises ValueError
+    mock_store = _make_store(
+        campaign_type="reddit_comment",
+        subs=[{"sub": "selfhosted", "active": 1, "occurrence": "weekly"}],
+    )
+    mock_strategy = MagicMock()
+    mock_strategy.supports_dupe_guard.return_value = False
+
+    with patch("app.services.poster.Store", return_value=mock_store):
+        with patch("app.services.poster.get_client", return_value=mock_strategy):
+            with patch("app.services.poster.date") as mock_date:
+                from datetime import date as real_date
+                mock_date.today.return_value = real_date(2026, 5, 3)
+                result = _run_post(db, campaign_id=1, target="selfhosted", triggered_by="scheduler")
+
+    assert result.get("skipped") is True
+    assert "invalid occurrence" in result.get("reason", "")
+    mock_strategy.execute.assert_not_called()