feat: Add comprehensive test coverage for Event model

- Add tests for SEO-friendly slug generation with name, venue, and city
- Add tests for slug uniqueness and fallback behavior
- Add tests for image URL validation and handling
- Add tests for image detection methods (has_image?, display_image)
- Fix duplicate has_image? method in Event model
- Remove duplicate test method to resolve test failures
- All 50 tests now passing

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

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

test/models/event_test.rb

@@ -317,4 +317,157 @@ class EventTest < ActiveSupport::TestCase
     # Check that ticket types were NOT duplicated
     assert_equal 0, duplicated_event.ticket_types.count
   end
+
+  # Test slug generation functionality
+  test "should generate slug from name and venue" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+    event = Event.new(
+      name: "Soirée d'ouverture",
+      description: "Valid description for the event that is long enough",
+      venue_name: "Test Venue",
+      venue_address: "123 Test Street",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0
+    )
+    event.save
+    assert_equal "soiree-d-ouverture-test-venue", event.slug
+  end
+
+  test "should generate slug from name, venue, and city" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+    event = Event.new(
+      name: "Fête de la Musique",
+      venue_name: "Théâtre Principal",
+      venue_address: "15 Rue de la Paix, 75002 Paris",
+      description: "Valid description for the event that is long enough",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0
+    )
+    event.save
+    assert_equal "fete-de-la-musique-theatre-principal-paris", event.slug
+  end
+
+  test "should generate fallback slug when no data available" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+    event = Event.new(
+      description: "Valid description for the event that is long enough",
+      venue_address: "123 Test Street",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0
+    )
+    event.save
+    assert_match /^event-\d+$/, event.slug
+  end
+
+  test "should ensure slug uniqueness" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+
+    # Create first event
+    event1 = Event.create!(
+      name: "Test Event",
+      venue_name: "Venue",
+      venue_address: "123 Test Street",
+      description: "Valid description for the event that is long enough",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0
+    )
+
+    # Create second event with same details
+    event2 = Event.create!(
+      name: "Test Event",
+      venue_name: "Venue",
+      venue_address: "123 Test Street",
+      description: "Valid description for the event that is long enough",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0
+    )
+
+    assert_not_equal event1.slug, event2.slug
+    assert_match /^test-event-venue-1$/, event2.slug
+  end
+
+  test "should extract city from French postal code" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+    event = Event.new(
+      name: "Concert",
+      venue_address: "5 Avenue des Champs-Élysées, 75008 Paris",
+      description: "Valid description for the event that is long enough",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0
+    )
+    event.save
+    assert event.slug.include?("paris")
+  end
+
+  # Test image URL functionality
+  test "should accept valid image URL" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+    event = Event.new(
+      name: "Event with URL Image",
+      slug: "event-url-image",
+      description: "Valid description for the event that is long enough",
+      venue_name: "Venue",
+      venue_address: "123 Test Street",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0,
+      image_url: "https://example.com/image.jpg"
+    )
+    assert event.valid?
+  end
+
+  test "should reject invalid image URL" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+    event = Event.new(
+      name: "Event with Invalid URL",
+      slug: "event-invalid-url",
+      description: "Valid description for the event that is long enough",
+      venue_name: "Venue",
+      venue_address: "123 Test Street",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0,
+      image_url: "not-a-valid-url"
+    )
+    assert_not event.valid?
+    assert_includes event.errors[:image_url], "doit être une URL valide vers une image (JPG, PNG, GIF, WebP)"
+  end
+
+  test "should reject URL with non-image extension" do
+    user = User.create!(email: "test@example.com", password: "password123", password_confirmation: "password123")
+    event = Event.new(
+      name: "Event with Non-image URL",
+      slug: "event-non-image-url",
+      description: "Valid description for the event that is long enough",
+      venue_name: "Venue",
+      venue_address: "123 Test Street",
+      user: user,
+      latitude: 48.0,
+      longitude: 2.0,
+      image_url: "https://example.com/document.pdf"
+    )
+    assert_not event.valid?
+    assert_includes event.errors[:image_url], "doit être une URL valide vers une image (JPG, PNG, GIF, WebP)"
+  end
+
+  test "has_image? should return true for URL image" do
+    event = Event.new(image_url: "https://example.com/image.jpg")
+    assert event.has_image?
+  end
+
+  test "has_image? should return false without image" do
+    event = Event.new
+    assert_not event.has_image?
+  end
+
+  test "display_image should return image URL when no attached image" do
+    event = Event.new(image_url: "https://example.com/image.jpg")
+    assert_equal "https://example.com/image.jpg", event.display_image
+  end
 end