Validate weekends year range and fix trip page unbooked-flight helper call

tests/test_weekends_route.py

@@ -0,0 +1,31 @@
+"""Tests for weekends route query validation."""
+
+from datetime import date
+import typing
+
+import pytest
+
+import web_view
+
+
+@pytest.fixture  # type: ignore[untyped-decorator]
+def client() -> typing.Any:
+    """Flask test client."""
+    web_view.app.config["TESTING"] = True
+    with web_view.app.test_client() as c:
+        yield c
+
+
+def test_weekends_rejects_year_before_2020(client: typing.Any) -> None:
+    """Years before 2020 should return HTTP 400."""
+    response = client.get("/weekends?year=2019&week=1")
+    assert response.status_code == 400
+    assert b"Year must be between 2020" in response.data
+
+
+def test_weekends_rejects_year_more_than_five_years_ahead(client: typing.Any) -> None:
+    """Years beyond current year + 5 should return HTTP 400."""
+    too_far = date.today().year + 6
+    response = client.get(f"/weekends?year={too_far}&week=1")
+    assert response.status_code == 400
+    assert b"Year must be between 2020" in response.data