Improve progressive results loading

tests/test_app.py

@@ -1,4 +1,7 @@
+from datetime import datetime
+
 import app as app_module
+import trip_planner as trip_planner_module
 
 
 def _client():
@@ -72,7 +75,7 @@ def test_search_redirects_return_with_return_date():
 
     assert resp.status_code == 302
     assert resp.headers['Location'].endswith(
-        '/results/BRI/paris/2026-04-10?journey_type=return&return_date=2026-04-17'
+        '/results/BRI/paris/2026-04-10/return/2026-04-17'
     )
 
 
@@ -91,6 +94,23 @@ def test_results_shows_same_day_destination_switcher(monkeypatch):
     assert 'ES 9014' in html
 
 
+def test_results_progressive_shell_loads_without_scraping(monkeypatch):
+    def fail_fetch(*args, **kwargs):
+        raise AssertionError("progressive shell should not fetch data")
+
+    monkeypatch.setattr(app_module.rtt_scraper, 'fetch', fail_fetch)
+    monkeypatch.setattr(app_module.eurostar_scraper, 'fetch', fail_fetch)
+    monkeypatch.setattr(app_module.gwr_fares_scraper, 'fetch', fail_fetch)
+    client = _client()
+
+    resp = client.get('/results/BRI/paris/2026-04-10?progressive=1')
+    html = resp.get_data(as_text=True)
+
+    assert resp.status_code == 200
+    assert 'Loading train times and fares' in html
+    assert 'render=full' in html
+
+
 def test_results_title_and_social_meta_include_destination(monkeypatch):
     _stub_data(monkeypatch)
     client = _client()
@@ -380,14 +400,39 @@ def test_results_return_renders_outbound_and_inbound_tables(monkeypatch):
             ],
         },
     )
+    monkeypatch.setattr(
+        trip_planner_module.circle_line,
+        'upcoming_services',
+        lambda earliest_board, count=2, direction='pad_to_kx': (
+            [
+                (datetime(2026, 4, 10, 9, 10), datetime(2026, 4, 10, 9, 25)),
+                (datetime(2026, 4, 10, 9, 15), datetime(2026, 4, 10, 9, 30)),
+            ]
+            if direction == 'pad_to_kx'
+            else [
+                (datetime(2026, 4, 17, 16, 40), datetime(2026, 4, 17, 16, 55)),
+                (datetime(2026, 4, 17, 16, 45), datetime(2026, 4, 17, 17, 0)),
+            ]
+        ),
+    )
     client = _client()
 
-    resp = client.get('/results/BRI/paris/2026-04-10?journey_type=return&return_date=2026-04-17')
+    resp = client.get('/results/BRI/paris/2026-04-10/return/2026-04-17')
     html = resp.get_data(as_text=True)
 
     assert resp.status_code == 200
     assert 'Outbound: Bristol Temple Meads → Paris Gare du Nord' in html
     assert 'Return: Paris Gare du Nord → Bristol Temple Meads' in html
+    assert '/results/BRI/paris/2026-04-09/return/2026-04-17' in html
+    assert '/results/BRI/paris/2026-04-11/return/2026-04-17' in html
+    assert "/results/BRI/paris/2026-04-10/return/2026-04-17" in html
+    assert 'journey_type=return' not in html
+    assert 'return_date=2026-04-17' not in html
+    assert 'Circle 09:10 → KX 09:25' in html
+    assert 'next 09:15 → KX 09:30' in html
+    assert 'Circle 16:40 → PAD 16:55' in html
+    assert 'next 16:45 → PAD 17:00' in html
+    assert 'title="Tight connection">⚠️</span>' in html
     assert 'ES 9014' in html
     assert 'ES 9035' in html