fix(html): fix hashCode for triangle

The bug caused HTML class and CSS selector to have different IDs, breaking triangle rendering.

src/test/java/ovh/gasser/newshapes/SelectionTest.java

@@ -0,0 +1,144 @@
+package ovh.gasser.newshapes;
+
+import org.junit.jupiter.api.Test;
+import ovh.gasser.newshapes.attributes.SelectionAttributes;
+import ovh.gasser.newshapes.shapes.SCircle;
+import ovh.gasser.newshapes.shapes.SRectangle;
+import ovh.gasser.newshapes.shapes.STriangle;
+import ovh.gasser.newshapes.ui.listeners.SelectionListener;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class SelectionTest {
+
+    @Test
+    void testIsEmptyInitially() {
+        Selection selection = new Selection();
+        assertTrue(selection.isEmpty());
+    }
+
+    @Test
+    void testAdd() {
+        Selection selection = new Selection();
+        SCircle circle = SCircle.create(0, 0, 50);
+
+        selection.add(circle);
+
+        assertFalse(selection.isEmpty());
+        assertEquals(1, selection.getSelectedShapes().size());
+        assertTrue(selection.getSelectedShapes().contains(circle));
+
+        // Verify shape is marked as selected
+        SelectionAttributes attrs = (SelectionAttributes) circle.getAttributes(SelectionAttributes.ID);
+        assertNotNull(attrs);
+        assertTrue(attrs.selected);
+    }
+
+    @Test
+    void testAddAll() {
+        Selection selection = new Selection();
+        SCircle circle1 = SCircle.create(0, 0, 50);
+        SRectangle rect = SRectangle.create(10, 10, 100, 50);
+        STriangle triangle = STriangle.create(50, 50, 30, java.awt.Color.BLACK, java.awt.Color.BLACK);
+
+        List<ovh.gasser.newshapes.shapes.Shape> shapes = Arrays.asList(circle1, rect, triangle);
+        selection.addAll(shapes);
+
+        assertEquals(3, selection.getSelectedShapes().size());
+        assertTrue(selection.getSelectedShapes().contains(circle1));
+        assertTrue(selection.getSelectedShapes().contains(rect));
+        assertTrue(selection.getSelectedShapes().contains(triangle));
+    }
+
+    @Test
+    void testClear() {
+        Selection selection = new Selection();
+        SCircle circle = SCircle.create(0, 0, 50);
+        SRectangle rect = SRectangle.create(10, 10, 100, 50);
+
+        selection.add(circle);
+        selection.add(rect);
+
+        assertFalse(selection.isEmpty());
+        assertEquals(2, selection.getSelectedShapes().size());
+
+        selection.clear();
+
+        assertTrue(selection.isEmpty());
+        assertEquals(0, selection.getSelectedShapes().size());
+
+        // Verify shapes are marked as unselected
+        SelectionAttributes circleAttrs = (SelectionAttributes) circle.getAttributes(SelectionAttributes.ID);
+        SelectionAttributes rectAttrs = (SelectionAttributes) rect.getAttributes(SelectionAttributes.ID);
+
+        assertNotNull(circleAttrs);
+        assertNotNull(rectAttrs);
+        assertFalse(circleAttrs.selected);
+        assertFalse(rectAttrs.selected);
+    }
+
+    @Test
+    void testGetSelectedShapesReturnsCopy() {
+        Selection selection = new Selection();
+        SCircle circle = SCircle.create(0, 0, 50);
+        selection.add(circle);
+
+        List<ovh.gasser.newshapes.shapes.Shape> copy = selection.getSelectedShapes();
+
+        // Try to modify the copy
+        assertThrows(UnsupportedOperationException.class, () -> copy.add(SCircle.create(10, 10, 20)));
+
+        // Original should be unchanged
+        assertEquals(1, selection.getSelectedShapes().size());
+    }
+
+    @Test
+    void testAddListener() {
+        Selection selection = new Selection();
+        AtomicBoolean listenerNotified = new AtomicBoolean(false);
+        AtomicInteger notificationCount = new AtomicInteger(0);
+
+        SelectionListener listener = (selectedShapes) -> {
+            listenerNotified.set(true);
+            notificationCount.incrementAndGet();
+        };
+
+        selection.addListener(listener);
+
+        // Adding a shape should notify listener
+        SCircle circle = SCircle.create(0, 0, 50);
+        selection.add(circle);
+
+        assertTrue(listenerNotified.get());
+        assertEquals(1, notificationCount.get());
+
+        // Adding another shape should notify listener again
+        SRectangle rect = SRectangle.create(10, 10, 100, 50);
+        selection.add(rect);
+
+        assertEquals(2, notificationCount.get());
+
+        // Clearing should notify listener
+        selection.clear();
+
+        assertEquals(3, notificationCount.get());
+    }
+
+    @Test
+    void testNullAddAllDoesNothing() {
+        Selection selection = new Selection();
+
+        // Should not throw
+        assertDoesNotThrow(() -> selection.addAll(null));
+
+        // Selection should still be empty
+        assertTrue(selection.isEmpty());
+    }
+}