Allow same-day return journeys in the date selector

Select the outbound date again to complete a day trip, with a clear hint and summary and no misleading range highlight. Cover desktop and mobile selection, submission, and reselection with Playwright.

Closes #9

templates/index.html

@@ -122,7 +122,7 @@
           <button type="button" id="cal-next" class="cal-nav-btn" aria-label="Next month">&#8250;</button>
         </div>
         <div id="cal-months"></div>
-        <div id="cal-hint" class="cal-hint"></div>
+        <div id="cal-hint" class="cal-hint" aria-live="polite"></div>
       </div>
       <!-- Hidden inputs submitted with the form -->
       <input type="hidden" id="travel_date" name="travel_date">
@@ -258,12 +258,7 @@
         retPhase = true;
       } else {
         /* selecting return date */
-        if (sameDay(d, outDate)) {
+        if (d < outDate) {
-          /* tapped same day → reset */
-          outDate  = null;
-          retDate  = null;
-          retPhase = false;
-        } else if (d < outDate) {
           /* earlier than outbound → new outbound, keep retPhase */
           outDate = d;
         } else {
@@ -309,7 +304,7 @@
     function buildMonth(year, month) {
       /* effective range (includes hover preview) */
       var rangeA = null, rangeB = null;
-      if (outDate && retDate) {
+      if (outDate && retDate && !sameDay(outDate, retDate)) {
         rangeA = outDate < retDate ? outDate : retDate;
         rangeB = outDate < retDate ? retDate : outDate;
       } else if (outDate && retPhase && hoverDate && hoverDate > outDate) {
@@ -419,6 +414,9 @@
     /* ── hover range: update cell styles in-place (no DOM rebuild) ───── */
 
     function applyHoverStyles(rangeA, rangeB) {
+      if (!rangeA || !rangeB || rangeB <= rangeA) {
+        rangeA = rangeB = null;
+      }
       document.querySelectorAll('.cal-cell[data-date]').forEach(function (cell) {
         var d   = new Date(cell.getAttribute('data-date') + 'T00:00:00');
         var col = parseInt(cell.getAttribute('data-col'), 10);
@@ -451,7 +449,10 @@
         el.innerHTML = '<span class="cal-cta">Select outbound date</span>';
       } else if (retPhase) {
         el.innerHTML = 'Outbound: <strong>' + dispDate(outDate) +
-          '</strong> &nbsp;&middot;&nbsp; <span class="cal-cta">Now select return date</span>';
+          '</strong> &nbsp;&middot;&nbsp; <span class="cal-cta">Now select return date</span>' +
+          ' — select the same date for a day trip.';
+      } else if (sameDay(outDate, retDate)) {
+        el.innerHTML = 'Day trip: <strong>' + dispDate(outDate) + '</strong> (out and back)';
       } else {
         el.innerHTML = 'Outbound: <strong>' + dispDate(outDate) +
           '</strong> &nbsp;&middot;&nbsp; Return: <strong>' + dispDate(retDate) + '</strong>';

tests/test_playwright_return_fares.py

@@ -1,4 +1,5 @@
 import threading
+from datetime import date, timedelta
 from typing import Any, Generator
 
 import pytest
@@ -647,29 +648,91 @@ def test_return_advance_first_standard_premier_totals(local_server: str) -> None
         browser.close()
 
 
-def test_return_calendar_selects_outbound_before_return(local_server: str) -> None:
+@pytest.mark.parametrize("return_days", [0, 7], ids=["day-trip", "longer-trip"])
+@pytest.mark.parametrize("mobile", [False, True], ids=["desktop", "mobile"])
+def test_return_calendar_selects_outbound_before_return(
+    local_server: str, return_days: int, mobile: bool
+) -> None:
     with sync_playwright() as p:
         browser = _launch_browser(p)
-        page = browser.new_page()
+        page = browser.new_page(
+            viewport={"width": 390 if mobile else 1280, "height": 844},
+            has_touch=mobile,
+        )
         page.goto(f"{local_server}/", wait_until="domcontentloaded")
+        today = date.fromisoformat(page.locator("#travel_date").input_value())
+        outbound = (today + timedelta(days=1)).isoformat()
+        returning = (today + timedelta(days=1 + return_days)).isoformat()
 
-        page.locator("#journey-return").check(force=True)
+        def select_day(value: str) -> None:
+            button = page.locator(f'.cal-cell[data-date="{value}"] button')
+            if mobile:
+                button.tap()
+            else:
+                button.click()
+
+        page.locator("#journey-return").check()
         assert page.locator("#cal-hint").inner_text() == "Select outbound date"
         assert page.locator("#travel_date").input_value() == ""
         assert page.locator("#return_date").input_value() == ""
 
-        page.get_by_role("button", name="10 June 2026").click()
+        select_day(outbound)
-        assert page.locator("#travel_date").input_value() == "2026-06-10"
+        assert page.locator("#travel_date").input_value() == outbound
         assert page.locator("#return_date").input_value() == ""
         assert "Now select return date" in page.locator("#cal-hint").inner_text()
+        assert "same date for a day trip" in page.locator("#cal-hint").inner_text()
 
-        page.get_by_role("button", name="17 June 2026").click()
+        select_day(returning)
-        assert page.locator("#travel_date").input_value() == "2026-06-10"
+        assert page.locator("#travel_date").input_value() == outbound
-        assert page.locator("#return_date").input_value() == "2026-06-17"
+        assert page.locator("#return_date").input_value() == returning
-        assert "Return: Wed 17 Jun" in page.locator("#cal-hint").inner_text()
+        assert page.locator("#return_date").get_attribute("name") == "return_date"
+        hint = page.locator("#cal-hint").inner_text()
+        assert ("Day trip:" if return_days == 0 else "Return:") in hint
+        if return_days == 0:
+            assert page.locator(".cal-selected").count() == 1
+            # A day trip must not show a range extending into the next day,
+            # including after the pointer leaves the calendar.
+            page.locator("h2").hover()
+            assert page.locator(".cal-in-range").count() == 0
+            assert page.locator(f'.cal-cell[data-date="{outbound}"]').evaluate(
+                "el => el.style.background"
+            ) == ""
+        assert page.evaluate(
+            "document.documentElement.scrollWidth <= window.innerWidth"
+        )
 
         page.locator('button[type="submit"]').click()
-        page.wait_for_url("**/results/BRI/paris/return/2026-06-10/2026-06-17", timeout=10000)
+        page.wait_for_url(
+            f"**/results/BRI/paris/return/{outbound}/{returning}", timeout=10000
+        )
+        browser.close()
+
+
+def test_return_calendar_can_restart_and_move_outbound_earlier(local_server: str) -> None:
+    with sync_playwright() as p:
+        browser = _launch_browser(p)
+        page = browser.new_page()
+        page.goto(f"{local_server}/", wait_until="domcontentloaded")
+        today = date.fromisoformat(page.locator("#travel_date").input_value())
+        tomorrow = (today + timedelta(days=1)).isoformat()
+        page.locator("#journey-return").check()
+        day = page.locator(f'.cal-cell[data-date="{tomorrow}"] button')
+        day.click()
+        day.click()
+        assert page.locator("#return_date").input_value() == tomorrow
+
+        # The next click starts a fresh selection, even on the selected date.
+        day.click()
+        assert page.locator("#return_date").input_value() == ""
+        page.locator(f'.cal-cell[data-date="{today}"] button').click()
+        assert page.locator("#travel_date").input_value() == today.isoformat()
+        assert page.locator("#return_date").input_value() == ""
+        day.click()
+        assert page.locator("#return_date").input_value() == tomorrow
+
+        page.locator("#journey-outbound").check()
+        assert page.locator("#travel_date").input_value() == today.isoformat()
+        assert page.locator("#return_date").get_attribute("name") == ""
         browser.close()