Support inexact conference dates

Closes: #188

tests/test_conference_list.py

@@ -0,0 +1,55 @@
+"""Tests for conference list date handling."""
+
+from datetime import date
+import typing
+
+import yaml
+
+import agenda.trip
+import web_view
+
+
+def test_build_conference_list_supports_inexact_dates(
+    tmp_path: typing.Any, monkeypatch: typing.Any
+) -> None:
+    """Conference list should include tentative and approximate dates."""
+    conferences = [
+        {
+            "name": "PyCascades 2027",
+            "topic": "Python",
+            "location": "TBC",
+            "dates": {
+                "status": "approximate",
+                "label": "March 2027",
+                "earliest": date(2027, 3, 1),
+                "latest": date(2027, 3, 31),
+            },
+        },
+        {
+            "name": "FOSDEM 2027",
+            "topic": "FOSDEM",
+            "location": "Brussels",
+            "dates": {
+                "status": "tentative",
+                "start": date(2027, 1, 30),
+                "end": date(2027, 1, 31),
+                "label": "likely first weekend of February 2027",
+            },
+        },
+    ]
+    (tmp_path / "conferences.yaml").write_text(
+        yaml.safe_dump(conferences), encoding="utf-8"
+    )
+
+    monkeypatch.setitem(web_view.app.config, "PERSONAL_DATA", str(tmp_path))
+    monkeypatch.setattr(agenda.trip, "build_trip_list", lambda: [])
+
+    items = web_view.build_conference_list()
+
+    assert [item["name"] for item in items] == ["FOSDEM 2027", "PyCascades 2027"]
+    assert items[0]["date_status"] == "tentative"
+    assert items[0]["display_date"] == "likely first weekend of February 2027"
+    assert items[0]["sort_date"] == date(2027, 1, 30)
+    assert items[1]["date_status"] == "approximate"
+    assert items[1]["display_date"] == "March 2027"
+    assert items[1]["latest_date"] == date(2027, 3, 31)