feat: add comprehensive tests for Story 2.3 View Exchange Details

Add integration tests covering all acceptance criteria:
- Clicking an exchange opens detail view
- Shows all exchange information
- Shows list of registered participants
- Shows current state
- Shows registration link (when applicable)
- Handle missing optional fields gracefully
- Navigation back to dashboard

Story: 2.3

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/integration/test_view_exchange_details.py

@@ -0,0 +1,330 @@
+"""Integration tests for Story 2.3: View Exchange Details."""
+
+from datetime import datetime, timedelta
+
+from src.models import Exchange
+
+
+class TestViewExchangeDetails:
+    """Test cases for viewing exchange details (Story 2.3)."""
+
+    def test_view_exchange_details_page(self, client, db, admin):  # noqa: ARG002
+        """Test that exchange detail page loads.
+
+        Acceptance Criteria:
+        - Clicking an exchange opens detail view
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Create an exchange
+        future_close_date = datetime.utcnow() + timedelta(days=7)
+        future_exchange_date = datetime.utcnow() + timedelta(days=14)
+
+        exchange = Exchange(
+            slug=Exchange.generate_slug(),
+            name="Test Exchange",
+            description="Test description",
+            budget="$20-30",
+            max_participants=10,
+            registration_close_date=future_close_date,
+            exchange_date=future_exchange_date,
+            timezone="America/New_York",
+            state=Exchange.STATE_DRAFT,
+        )
+
+        db.session.add(exchange)
+        db.session.commit()
+
+        # View exchange details
+        response = client.get(f"/admin/exchange/{exchange.id}")
+        assert response.status_code == 200
+
+    def test_exchange_details_shows_all_information(self, client, db, admin):  # noqa: ARG002
+        """Test that all exchange information is displayed.
+
+        Acceptance Criteria:
+        - Shows all exchange information
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Create an exchange with all fields
+        future_close_date = datetime.utcnow() + timedelta(days=7)
+        future_exchange_date = datetime.utcnow() + timedelta(days=14)
+
+        exchange = Exchange(
+            slug=Exchange.generate_slug(),
+            name="Family Christmas 2025",
+            description="Annual family gift exchange",
+            budget="$20-30",
+            max_participants=20,
+            registration_close_date=future_close_date,
+            exchange_date=future_exchange_date,
+            timezone="America/New_York",
+            state=Exchange.STATE_REGISTRATION_OPEN,
+        )
+
+        db.session.add(exchange)
+        db.session.commit()
+
+        # View exchange details
+        response = client.get(f"/admin/exchange/{exchange.id}")
+        assert response.status_code == 200
+
+        # Verify all exchange information is displayed
+        assert b"Family Christmas 2025" in response.data
+        assert b"Annual family gift exchange" in response.data
+        assert b"$20-30" in response.data
+        assert b"20" in response.data  # max_participants
+        assert b"America/New_York" in response.data
+        assert b"registration_open" in response.data
+
+    def test_exchange_details_shows_current_state(self, client, db, admin):  # noqa: ARG002
+        """Test that current state is displayed.
+
+        Acceptance Criteria:
+        - Shows current state
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Create exchanges in different states
+        future_close_date = datetime.utcnow() + timedelta(days=7)
+        future_exchange_date = datetime.utcnow() + timedelta(days=14)
+
+        draft_exchange = Exchange(
+            slug=Exchange.generate_slug(),
+            name="Draft Exchange",
+            budget="$20-30",
+            max_participants=10,
+            registration_close_date=future_close_date,
+            exchange_date=future_exchange_date,
+            timezone="America/New_York",
+            state=Exchange.STATE_DRAFT,
+        )
+
+        db.session.add(draft_exchange)
+        db.session.commit()
+
+        # View details
+        response = client.get(f"/admin/exchange/{draft_exchange.id}")
+        assert response.status_code == 200
+        assert b"draft" in response.data
+
+    def test_exchange_details_shows_registration_link(self, client, db, admin):  # noqa: ARG002
+        """Test that registration link is shown.
+
+        Acceptance Criteria:
+        - Shows registration link (when applicable)
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Create an exchange
+        future_close_date = datetime.utcnow() + timedelta(days=7)
+        future_exchange_date = datetime.utcnow() + timedelta(days=14)
+
+        exchange = Exchange(
+            slug=Exchange.generate_slug(),
+            name="Test Exchange",
+            budget="$20-30",
+            max_participants=10,
+            registration_close_date=future_close_date,
+            exchange_date=future_exchange_date,
+            timezone="America/New_York",
+            state=Exchange.STATE_DRAFT,
+        )
+
+        db.session.add(exchange)
+        db.session.commit()
+
+        # View exchange details
+        response = client.get(f"/admin/exchange/{exchange.id}")
+        assert response.status_code == 200
+
+        # Verify registration link is displayed with the exchange slug
+        assert exchange.slug.encode() in response.data
+        assert b"/exchange/" in response.data
+        assert b"/register" in response.data
+
+    def test_exchange_details_shows_participant_list(self, client, db, admin):  # noqa: ARG002
+        """Test that participant list is shown (empty initially).
+
+        Acceptance Criteria:
+        - Shows list of registered participants
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Create an exchange
+        future_close_date = datetime.utcnow() + timedelta(days=7)
+        future_exchange_date = datetime.utcnow() + timedelta(days=14)
+
+        exchange = Exchange(
+            slug=Exchange.generate_slug(),
+            name="Test Exchange",
+            budget="$20-30",
+            max_participants=10,
+            registration_close_date=future_close_date,
+            exchange_date=future_exchange_date,
+            timezone="America/New_York",
+            state=Exchange.STATE_DRAFT,
+        )
+
+        db.session.add(exchange)
+        db.session.commit()
+
+        # View exchange details
+        response = client.get(f"/admin/exchange/{exchange.id}")
+        assert response.status_code == 200
+
+        # Verify participant section exists
+        assert b"Participants" in response.data or b"participants" in response.data
+        # Since no participants yet, should show empty message
+        assert (
+            b"No participants yet" in response.data
+            or b"no participants" in response.data.lower()
+        )
+
+    def test_exchange_details_not_found(self, client, db, admin):  # noqa: ARG002
+        """Test that 404 is returned for non-existent exchange.
+
+        Acceptance Criteria:
+        - Handle non-existent exchange gracefully
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Try to view non-existent exchange
+        response = client.get("/admin/exchange/99999")
+        assert response.status_code == 404
+
+    def test_exchange_details_handles_missing_description(self, client, db, admin):  # noqa: ARG002
+        """Test that missing optional fields are handled gracefully.
+
+        Acceptance Criteria:
+        - Shows all exchange information
+        - Handle optional fields (description)
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Create exchange without description
+        future_close_date = datetime.utcnow() + timedelta(days=7)
+        future_exchange_date = datetime.utcnow() + timedelta(days=14)
+
+        exchange = Exchange(
+            slug=Exchange.generate_slug(),
+            name="Test Exchange",
+            description=None,  # No description
+            budget="$20-30",
+            max_participants=10,
+            registration_close_date=future_close_date,
+            exchange_date=future_exchange_date,
+            timezone="America/New_York",
+            state=Exchange.STATE_DRAFT,
+        )
+
+        db.session.add(exchange)
+        db.session.commit()
+
+        # View exchange details
+        response = client.get(f"/admin/exchange/{exchange.id}")
+        assert response.status_code == 200
+
+        # Should handle missing description gracefully
+        assert (
+            b"No description" in response.data
+            or b"no description" in response.data.lower()
+        )
+
+    def test_exchange_details_navigation(self, client, db, admin):  # noqa: ARG002
+        """Test that navigation back to dashboard exists.
+
+        Acceptance Criteria:
+        - Provide navigation back to dashboard
+        """
+        # Login first
+        client.post(
+            "/admin/login",
+            data={
+                "email": "admin@example.com",
+                "password": "testpassword123",
+            },
+            follow_redirects=True,
+        )
+
+        # Create an exchange
+        future_close_date = datetime.utcnow() + timedelta(days=7)
+        future_exchange_date = datetime.utcnow() + timedelta(days=14)
+
+        exchange = Exchange(
+            slug=Exchange.generate_slug(),
+            name="Test Exchange",
+            budget="$20-30",
+            max_participants=10,
+            registration_close_date=future_close_date,
+            exchange_date=future_exchange_date,
+            timezone="America/New_York",
+            state=Exchange.STATE_DRAFT,
+        )
+
+        db.session.add(exchange)
+        db.session.commit()
+
+        # View exchange details
+        response = client.get(f"/admin/exchange/{exchange.id}")
+        assert response.status_code == 200
+
+        # Verify back link to dashboard exists
+        assert b"dashboard" in response.data.lower() or b"back" in response.data.lower()