feat(03-01): add GravityApplier with native PhysicsValues.invertedGravity toggle (Task 1)

- Service GravityApplier qui toggle PhysicsValues.invertedGravity via CommandBuffer.replaceComponent - Thread-safe tracker ConcurrentHashMap.newKeySet<UUID> pour dedup entre ticks - Second pass O(N) pour restaurer la gravité à la sortie de région (trade-off v1 documenté) - Pure diff static helper + hooks package-private pour tests unitaires sans runtime Hytale - 6 tests verts (diff + tracker semantics)
2026-04-23 10:31:43 +02:00
parent 562f60d343
commit ef3f398c55
2 changed files with 268 additions and 0 deletions
@@ -0,0 +1,80 @@
+package com.mythlane.gravityflip.physics;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Pure-diff + tracker-semantics tests for {@link GravityApplier}.
+ *
+ * <p>Pas de mocks (pattern Phase 02-02 deviation #4). Pas de runtime Hytale requis —
+ * les tests 5 et 6 utilisent le hook package-private {@code __updateTrackerForTest} et
+ * la vue {@code previouslyInvertedView()} pour valider la sémantique du tracker sans
+ * toucher à {@code World} / {@code Store}.
+ */
+class GravityApplierDiffTest {
+
+    @Test
+    void diffComputesToFlipAndToRestore() {
+        UUID a = UUID.randomUUID(), b = UUID.randomUUID(), c = UUID.randomUUID(), d = UUID.randomUUID();
+        Set<UUID> previous = new HashSet<>(Set.of(a, b, c));
+        Set<UUID> current = new HashSet<>(Set.of(b, c, d));
+        GravityApplier.DiffResult res = GravityApplier.diff(previous, current);
+        assertEquals(Set.of(d), res.toFlip);
+        assertEquals(Set.of(a), res.toRestore);
+    }
+
+    @Test
+    void diffEmptyPreviousFlipsAll() {
+        UUID x = UUID.randomUUID(), y = UUID.randomUUID();
+        GravityApplier.DiffResult res = GravityApplier.diff(new HashSet<>(), new HashSet<>(Set.of(x, y)));
+        assertEquals(Set.of(x, y), res.toFlip);
+        assertTrue(res.toRestore.isEmpty());
+    }
+
+    @Test
+    void diffEmptyCurrentRestoresAll() {
+        UUID x = UUID.randomUUID(), y = UUID.randomUUID();
+        GravityApplier.DiffResult res = GravityApplier.diff(new HashSet<>(Set.of(x, y)), new HashSet<>());
+        assertTrue(res.toFlip.isEmpty());
+        assertEquals(Set.of(x, y), res.toRestore);
+    }
+
+    @Test
+    void diffNoChange() {
+        UUID a = UUID.randomUUID();
+        GravityApplier.DiffResult res = GravityApplier.diff(
+                new HashSet<>(Set.of(a)), new HashSet<>(Set.of(a)));
+        assertTrue(res.toFlip.isEmpty());
+        assertTrue(res.toRestore.isEmpty());
+    }
+
+    @Test
+    void trackerInitiallyEmpty() {
+        GravityApplier applier = new GravityApplier(t -> {});
+        assertTrue(applier.previouslyInvertedView().isEmpty());
+    }
+
+    @Test
+    void trackerEvolvesViaPackagePrivateUpdate() {
+        GravityApplier applier = new GravityApplier(t -> {});
+        UUID a = UUID.randomUUID(), b = UUID.randomUUID(), c = UUID.randomUUID();
+
+        applier.__updateTrackerForTest(new HashSet<>(Set.of(a, b)));
+        assertEquals(Set.of(a, b), applier.previouslyInvertedView());
+
+        applier.__updateTrackerForTest(new HashSet<>());
+        assertTrue(applier.previouslyInvertedView().isEmpty());
+
+        applier.__updateTrackerForTest(new HashSet<>(Set.of(c)));
+        assertEquals(Set.of(c), applier.previouslyInvertedView());
+
+        // View is immutable.
+        Set<UUID> view = applier.previouslyInvertedView();
+        assertThrows(UnsupportedOperationException.class, () -> view.add(UUID.randomUUID()));
+    }
+}