Improve stop search and add documentation

tests/test_uk_bus_stops.py

@@ -25,9 +25,13 @@ def test_geocode_limits_search_to_great_britain_and_identifies_app() -> None:
         json=[{"lat": "51.45", "lon": "-2.59", "display_name": "Bristol, England"}],
     )
     result = core.geocode("Bristol")
-    assert result == {"lat": 51.45, "lon": -2.59, "label": "Bristol, England"}
+    assert result == [{
+        "lat": 51.45, "lon": -2.59, "label": "Bristol, England", "type": None,
+    }]
     request = responses.calls[0].request
     assert "countrycodes=gb" in request.url
+    assert "limit=20" in request.url
+    assert "bounded=0" in request.url
     assert request.headers["User-Agent"].startswith("uk-bus-stops/")
     assert "edward@4angle.com" in request.headers["User-Agent"]
 
@@ -143,6 +147,7 @@ def test_place_name_is_not_mistaken_for_atco_code() -> None:
     """Long alphabetic place names still go through Nominatim geocoding."""
     assert ATCO_PATTERN.fullmatch("Manchester") is None
     assert ATCO_PATTERN.fullmatch("0100BRP90314") is not None
+    assert ATCO_PATTERN.fullmatch("010000056") is not None
 
 
 def test_parse_coordinates_accepts_valid_pair_and_rejects_invalid_pair() -> None:
@@ -165,6 +170,45 @@ def test_search_coordinates_bypasses_nominatim(client: Any) -> None:
     assert responses.calls[0].request.url.startswith(core.OVERPASS_URL)
 
 
+@responses.activate
+def test_geocode_uses_unbounded_map_bias() -> None:
+    """The map view biases Nominatim ranking without restricting its results."""
+    responses.get(core.NOMINATIM_URL, json=[])
+    assert core.geocode("North Street", viewbox=(-2.7, 51.4, -2.5, 51.5)) == []
+    url = responses.calls[0].request.url
+    assert "viewbox=-2.7%2C51.5%2C-2.5%2C51.4" in url
+    assert "bounded=0" in url
+
+
+@responses.activate
+def test_place_search_returns_uk_choices_before_loading_stops(client: Any) -> None:
+    """Ambiguous place searches return UK Nominatim choices without querying Overpass."""
+    responses.get(core.NOMINATIM_URL, json=[
+        {"lat": "51.1", "lon": "-1.3", "display_name": "North Street, Winchester",
+         "type": "residential"},
+        {"lat": "51.4", "lon": "-2.6", "display_name": "North Street, Bristol",
+         "type": "secondary"},
+    ])
+    response = client.get(
+        "/api/search?q=North+Street&west=-2.7&south=51.4&east=-2.5&north=51.5"
+    )
+    assert response.status_code == 200
+    data = response.get_json()
+    assert data["kind"] == "geocode"
+    assert [item["label"] for item in data["locations"]] == [
+        "North Street, Winchester", "North Street, Bristol",
+    ]
+    assert len(responses.calls) == 1
+    assert "viewbox=-2.7%2C51.5%2C-2.5%2C51.4" in responses.calls[0].request.url
+
+
+def test_search_rejects_partial_viewbox(client: Any) -> None:
+    """Search-bias bounds must contain all four valid coordinates."""
+    response = client.get("/api/search?q=North+Street&west=-2.7")
+    assert response.status_code == 400
+    assert response.get_json()["error"] == "invalid_viewbox"
+
+
 def test_location_coordinates_are_validated(client: Any) -> None:
     """Latitude and longitude must be numeric and within geographic ranges."""
     assert client.get("/api/stops?lat=hello&lon=1").status_code == 400
@@ -211,3 +255,16 @@ def test_index_contains_search_and_map(client: Any) -> None:
     assert b"Find a UK bus stop code" in response.data
     assert b'id="search-input"' in response.data
     assert b'id="map"' in response.data
+    assert b'href="/about"' in response.data
+
+
+def test_about_documents_urls_and_services(client: Any) -> None:
+    """The About page documents shareable links, APIs, and OSM data sources."""
+    response = client.get("/about")
+    assert response.status_code == 200
+    assert b"Shareable URL parameters" in response.data
+    assert b"?q=Bristol+Temple+Meads" in response.data
+    assert b"?node=485403178" in response.data
+    assert b"?lat=51.4545&lon=-2.5879" in response.data
+    assert b"overpass.atownsend.org.uk" in response.data
+    assert b"JSON endpoints" in response.data