Close door after walking through again, and add more test coverage

src/core/__tests__/math.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect } from 'vitest';
+import { seededRandom, manhattan, lerp } from '../math';
+
+describe('Math Utilities', () => {
+  describe('seededRandom', () => {
+    it('should return consistent results for the same seed', () => {
+      const rng1 = seededRandom(12345);
+      const rng2 = seededRandom(12345);
+      
+      expect(rng1()).toBe(rng2());
+      expect(rng1()).toBe(rng2());
+      expect(rng1()).toBe(rng2());
+    });
+
+    it('should return different results for different seeds', () => {
+      const rng1 = seededRandom(12345);
+      const rng2 = seededRandom(67890);
+      
+      expect(rng1()).not.toBe(rng2());
+    });
+  });
+
+  describe('manhattan', () => {
+    it('should calculate correct distance', () => {
+      expect(manhattan({ x: 0, y: 0 }, { x: 3, y: 4 })).toBe(7);
+      expect(manhattan({ x: 1, y: 1 }, { x: 4, y: 5 })).toBe(7);
+      expect(manhattan({ x: -1, y: -1 }, { x: -2, y: -2 })).toBe(2);
+    });
+  });
+
+  describe('lerp', () => {
+    it('should interpolate correctly', () => {
+      expect(lerp(0, 10, 0.5)).toBe(5);
+      expect(lerp(0, 10, 0)).toBe(0);
+      expect(lerp(0, 10, 1)).toBe(10);
+      expect(lerp(10, 20, 0.5)).toBe(15);
+    });
+  });
+});

src/core/__tests__/terrain.test.ts

@@ -0,0 +1,54 @@
+import { describe, it, expect } from 'vitest';
+import { 
+  TileType, 
+  isBlocking, 
+  isDestructible, 
+  blocksSight, 
+  getDestructionResult,
+  isDestructibleByWalk
+} from '../terrain';
+
+describe('Terrain', () => {
+  describe('Tile Definitions', () => {
+    it('should correctly identify blocking tiles', () => {
+      expect(isBlocking(TileType.WALL)).toBe(true);
+      expect(isBlocking(TileType.WALL_DECO)).toBe(true);
+      expect(isBlocking(TileType.WATER)).toBe(true);
+      
+      expect(isBlocking(TileType.EMPTY)).toBe(false);
+      expect(isBlocking(TileType.GRASS)).toBe(false);
+      expect(isBlocking(TileType.EXIT)).toBe(false);
+    });
+
+    it('should correctly identify destructible tiles', () => {
+      expect(isDestructible(TileType.GRASS)).toBe(true);
+      expect(isDestructible(TileType.DOOR_CLOSED)).toBe(true);
+      
+      expect(isDestructible(TileType.WALL)).toBe(false);
+      expect(isDestructible(TileType.EMPTY)).toBe(false);
+    });
+
+    it('should correctly identify tiles blocking sight', () => {
+      expect(blocksSight(TileType.WALL)).toBe(true);
+      expect(blocksSight(TileType.WALL_DECO)).toBe(true);
+      expect(blocksSight(TileType.DOOR_CLOSED)).toBe(true);
+      expect(blocksSight(TileType.GRASS)).toBe(true); // Grass blocks vision in this game logic
+      
+      expect(blocksSight(TileType.EMPTY)).toBe(false);
+      expect(blocksSight(TileType.EXIT)).toBe(false);
+    });
+
+    it('should return correct destruction result', () => {
+      expect(getDestructionResult(TileType.GRASS)).toBe(TileType.GRASS_SAPLINGS);
+      expect(getDestructionResult(TileType.DOOR_CLOSED)).toBe(TileType.DOOR_OPEN);
+      
+      expect(getDestructionResult(TileType.WALL)).toBeUndefined();
+    });
+    
+    it('should correctly identify tiles destructible by walk', () => {
+        expect(isDestructibleByWalk(TileType.GRASS)).toBe(true);
+        expect(isDestructibleByWalk(TileType.DOOR_CLOSED)).toBe(true);
+        expect(isDestructibleByWalk(TileType.WALL)).toBe(false);
+    });
+  });
+});

src/core/__tests__/utils.test.ts

@@ -0,0 +1,12 @@
+import { describe, it, expect } from 'vitest';
+import { key } from '../utils';
+
+describe('Utils', () => {
+  describe('key', () => {
+    it('should generate correct key string', () => {
+      expect(key(1, 2)).toBe('1,2');
+      expect(key(0, 0)).toBe('0,0');
+      expect(key(-5, 10)).toBe('-5,10');
+    });
+  });
+});

src/core/terrain.ts

@@ -32,7 +32,7 @@ export const TILE_DEFINITIONS: Record<number, TileBehavior> = {
   [TileType.EXIT]: { id: TileType.EXIT, isBlocking: false, isDestructible: false },
   [TileType.WATER]: { id: TileType.WATER, isBlocking: true, isDestructible: false },
   [TileType.DOOR_CLOSED]: { id: TileType.DOOR_CLOSED, isBlocking: false, isDestructible: true, isDestructibleByWalk: true, blocksVision: true, destructsTo: TileType.DOOR_OPEN },
-  [TileType.DOOR_OPEN]: { id: TileType.DOOR_OPEN, isBlocking: false, isDestructible: false }
+  [TileType.DOOR_OPEN]: { id: TileType.DOOR_OPEN, isBlocking: false, isDestructible: true, isDestructibleByWalk: true, blocksVision: false, destructsTo: TileType.DOOR_CLOSED }
 };
 
 export function isBlocking(tile: number): boolean {

src/core/types.ts

@@ -6,7 +6,7 @@ export type Tile = number;
 export type EnemyType = "rat" | "bat";
 export type ActorType = "player" | EnemyType;
 
-export type EnemyAIState = "wandering" | "alerted" | "pursuing";
+export type EnemyAIState = "wandering" | "alerted" | "pursuing" | "searching";
 
 export type Action =
   | { type: "move"; dx: number; dy: number }

src/engine/__tests__/generator.test.ts

@@ -174,5 +174,53 @@ describe('World Generator', () => {
       const avgHp5 = enemies5.reduce((sum, e) => sum + (e.stats.hp || 0), 0) / enemies5.length;
       expect(avgHp5).toBeGreaterThan(avgHp1);
     });
+    it('should generate doors on dungeon floors', () => {
+      const runState = {
+        stats: { 
+          maxHp: 20, hp: 20, attack: 5, defense: 2, level: 1, exp: 0, expToNextLevel: 10, maxMana: 20, mana: 20,
+          statPoints: 0, skillPoints: 0, strength: 10, dexterity: 10, intelligence: 10,
+          critChance: 5, critMultiplier: 150, accuracy: 90, lifesteal: 0, evasion: 5, blockChance: 0, luck: 0,
+          passiveNodes: [] 
+        },
+        inventory: { gold: 0, items: [] }
+      };
+
+      // Generate a few worlds to ensure we hit the 50% door chance at least once
+      let foundDoor = false;
+      for (let i = 0; i < 5; i++) {
+        const { world } = generateWorld(1, runState); // Floor 1 is Uniform (Dungeon)
+        if (world.tiles.some(t => t === 5 || t === 6)) { // 5=DOOR_CLOSED, 6=DOOR_OPEN
+          foundDoor = true;
+          break;
+        }
+      }
+      
+      expect(foundDoor).toBe(true);
+    });
+
+    it('should ensure player spawns on safe tile (not grass)', () => {
+      const runState = {
+        stats: { 
+          maxHp: 20, hp: 20, attack: 5, defense: 2, level: 1, exp: 0, expToNextLevel: 10, maxMana: 20, mana: 20,
+          statPoints: 0, skillPoints: 0, strength: 10, dexterity: 10, intelligence: 10,
+          critChance: 5, critMultiplier: 150, accuracy: 90, lifesteal: 0, evasion: 5, blockChance: 0, luck: 0,
+          passiveNodes: [] 
+        },
+        inventory: { gold: 0, items: [] }
+      };
+
+      // Generate multiple worlds to stress test spawn placement
+      for (let i = 0; i < 10; i++) {
+        const { world, playerId } = generateWorld(1, runState);
+        const player = world.actors.get(playerId)!;
+        
+        // Check tile under player
+        const tileIdx = player.pos.y * world.width + player.pos.x;
+        const tile = world.tiles[tileIdx];
+
+        // Should be EMPTY (1), specifically NOT GRASS (15) which blocks vision
+        expect(tile).toBe(1); // TileType.EMPTY
+      }
+    });
   });
 });

src/engine/__tests__/pathfinding.test.ts

@@ -0,0 +1,83 @@
+import { describe, it, expect } from 'vitest';
+import { findPathAStar } from '../world/pathfinding';
+import { type World } from '../../core/types';
+import { TileType } from '../../core/terrain';
+
+describe('Pathfinding', () => {
+    const createTestWorld = (width: number, height: number, tileType: number = TileType.EMPTY): World => ({
+        width,
+        height,
+        tiles: new Array(width * height).fill(tileType),
+        actors: new Map(),
+        exit: { x: 0, y: 0 }
+    });
+
+    it('should find a path between two reachable points', () => {
+        const world = createTestWorld(10, 10);
+        const seen = new Uint8Array(100).fill(1);
+        
+        const path = findPathAStar(world, seen, { x: 0, y: 0 }, { x: 0, y: 3 });
+        
+        expect(path.length).toBe(4); // 0,0 -> 0,1 -> 0,2 -> 0,3
+        expect(path[0]).toEqual({ x: 0, y: 0 });
+        expect(path[3]).toEqual({ x: 0, y: 3 });
+    });
+
+    it('should return empty array if target is a wall', () => {
+        const world = createTestWorld(10, 10);
+        world.tiles[30] = TileType.WALL; // Wall at 0,3
+        const seen = new Uint8Array(100).fill(1);
+        
+        const path = findPathAStar(world, seen, { x: 0, y: 0 }, { x: 0, y: 3 });
+        
+        expect(path).toEqual([]);
+    });
+
+    it('should return empty array if no path exists', () => {
+        const world = createTestWorld(10, 10);
+        // Create a wall blockage
+        for(let x=0; x<10; x++) world.tiles[10 + x] = TileType.WALL;
+        
+        const seen = new Uint8Array(100).fill(1);
+        
+        const path = findPathAStar(world, seen, { x: 0, y: 0 }, { x: 0, y: 5 });
+        
+        expect(path).toEqual([]);
+    });
+
+    it('should respect ignoreBlockedTarget option', () => {
+        const world = createTestWorld(10, 10);
+        // Place an actor at target
+        world.actors.set(1, { id: 1, pos: { x: 0, y: 3 }, type: 'rat' } as any);
+        
+        const seen = new Uint8Array(100).fill(1);
+        
+        // Without option, it should be blocked (because actor is there)
+        // Wait, default pathfinding might treat actors as blocking unless specified. 
+        // Let's check `isBlocked` usage in `pathfinding.ts`.
+        // It calls `isBlocked` which checks actors.
+        
+        // However, findPathAStar has logic:
+        // if (!options.ignoreBlockedTarget && isBlocked(w, end.x, end.y, options.em)) return [];
+        
+        const pathBlocked = findPathAStar(world, seen, { x: 0, y: 0 }, { x: 0, y: 3 });
+        expect(pathBlocked).toEqual([]);
+
+        const pathIgnored = findPathAStar(world, seen, { x: 0, y: 0 }, { x: 0, y: 3 }, { ignoreBlockedTarget: true });
+        expect(pathIgnored.length).toBeGreaterThan(0);
+        expect(pathIgnored[pathIgnored.length - 1]).toEqual({ x: 0, y: 3 });
+    });
+
+    it('should respect ignoreSeen option', () => {
+        const world = createTestWorld(10, 10);
+        const seen = new Uint8Array(100).fill(0); // Nothing seen
+        
+        // Without ignoreSeen, should fail because target/path is unseen
+        const pathUnseen = findPathAStar(world, seen, { x: 0, y: 0 }, { x: 0, y: 3 });
+        expect(pathUnseen).toEqual([]);
+        
+        // With ignoreSeen, should succeed
+        const pathSeenIgnored = findPathAStar(world, seen, { x: 0, y: 0 }, { x: 0, y: 3 }, { ignoreSeen: true });
+        expect(pathSeenIgnored.length).toBe(4);
+    });
+});

src/engine/__tests__/simulation.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { applyAction, decideEnemyAction } from '../simulation/simulation';
+import { applyAction, decideEnemyAction, stepUntilPlayerTurn } from '../simulation/simulation';
 import { type World, type Actor, type EntityId, type CombatantActor } from '../../core/types';
 import { EntityManager } from '../EntityManager';
 
@@ -126,5 +126,115 @@ describe('Combat Simulation', () => {
           const decision = decideEnemyAction(world, enemy, player, entityManager);
           expect(decision.action).toEqual({ type: "attack", targetId: 1 });
       });
+
+      it("should transition to alerted when spotting player", () => {
+          const actors = new Map<EntityId, Actor>();
+          const player = { id: 1, category: "combatant", isPlayer: true, pos: { x: 5, y: 0 }, stats: createTestStats() } as any;
+          const enemy = { 
+              id: 2, 
+              category: "combatant", 
+              isPlayer: false, 
+              pos: { x: 0, y: 0 }, 
+              stats: createTestStats(),
+              aiState: "wandering"
+          } as any;
+          actors.set(1, player);
+          actors.set(2, enemy);
+          const world = createTestWorld(actors);
+          
+          const decision = decideEnemyAction(world, enemy, player, new EntityManager(world));
+          
+          expect(enemy.aiState).toBe("alerted");
+          expect(decision.justAlerted).toBe(true);
+      });
+
+      it("should transition from pursuing to searching when sight is lost", () => {
+          const actors = new Map<EntityId, Actor>();
+          // Player far away (unseen)
+          const player = { id: 1, category: "combatant", isPlayer: true, pos: { x: 9, y: 9 }, stats: createTestStats() } as any;
+          const enemy = { 
+              id: 2, 
+              category: "combatant", 
+              isPlayer: false, 
+              pos: { x: 0, y: 0 }, 
+              stats: createTestStats(),
+              aiState: "pursuing", // Currently pursuing
+              lastKnownPlayerPos: { x: 5, y: 5 }
+          } as any;
+          actors.set(1, player);
+          actors.set(2, enemy);
+          const world = createTestWorld(actors);
+          
+          // Should switch to searching because can't see player
+          decideEnemyAction(world, enemy, player, new EntityManager(world));
+          
+          expect(enemy.aiState).toBe("searching");
+      });
+
+      it("should transition from searching to alerted when sight regained", () => {
+          const actors = new Map<EntityId, Actor>();
+          // Player adjacent (visible)
+          const player = { id: 1, category: "combatant", isPlayer: true, pos: { x: 1, y: 0 }, stats: createTestStats() } as any;
+          const enemy = { 
+              id: 2, 
+              category: "combatant", 
+              isPlayer: false, 
+              pos: { x: 0, y: 0 }, 
+              stats: createTestStats(),
+              aiState: "searching", 
+              lastKnownPlayerPos: { x: 5, y: 5 }
+          } as any;
+          actors.set(1, player);
+          actors.set(2, enemy);
+          const world = createTestWorld(actors);
+          
+          const decision = decideEnemyAction(world, enemy, player, new EntityManager(world));
+          
+          expect(enemy.aiState).toBe("alerted");
+          expect(decision.justAlerted).toBe(true);
+      });
+
+      it("should transition from searching to wandering when reached target", () => {
+          const actors = new Map<EntityId, Actor>();
+          // Player far away (unseen) - Manhattan dist > 8
+          // Enemy at 9,9. Player at 0,0. Dist = 18.
+          const player = { id: 1, category: "combatant", isPlayer: true, pos: { x: 0, y: 0 }, stats: createTestStats() } as any;
+          const enemy = { 
+              id: 2, 
+              category: "combatant", 
+              isPlayer: false, 
+              pos: { x: 9, y: 9 }, // At target
+              stats: createTestStats(),
+              aiState: "searching", 
+              lastKnownPlayerPos: { x: 9, y: 9 }
+          } as any;
+          actors.set(1, player);
+          actors.set(2, enemy);
+          const world = createTestWorld(actors);
+          
+          decideEnemyAction(world, enemy, player, new EntityManager(world));
+          
+          expect(enemy.aiState).toBe("wandering");
+      });
+  });
+
+  describe("stepUntilPlayerTurn", () => {
+      it("should process enemy turns", () => {
+          const actors = new Map<EntityId, Actor>();
+          // Player is slow, enemy is fast. Enemy should move before player returns.
+          const player = { id: 1, category: "combatant", isPlayer: true, pos: { x: 0, y: 0 }, speed: 10, stats: createTestStats() } as any;
+          const enemy = { id: 2, category: "combatant", isPlayer: false, pos: { x: 5, y: 5 }, speed: 100, stats: createTestStats() } as any;
+          
+          actors.set(1, player);
+          actors.set(2, enemy);
+          const world = createTestWorld(actors);
+          const em = new EntityManager(world);
+
+          const result = stepUntilPlayerTurn(world, 1, em);
+          
+          // Enemy should have taken at least one action
+          expect(result.events.length).toBeGreaterThan(0);
+          expect(result.awaitingPlayerId).toBe(1);
+      });
   });
 });

src/engine/__tests__/world.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { idx, inBounds, isWall, isBlocked } from '../world/world-logic';
+import { idx, inBounds, isWall, isBlocked, tryDestructTile, isPlayerOnExit } from '../world/world-logic';
 import { type World, type Tile } from '../../core/types';
 import { TileType } from '../../core/terrain';
 
@@ -114,4 +114,65 @@ describe('World Utilities', () => {
       expect(isBlocked(world, 10, 10)).toBe(true);
     });
   });
+  describe('tryDestructTile', () => {
+    it('should destruct a destructible tile', () => {
+      const tiles = new Array(100).fill(TileType.EMPTY);
+      tiles[0] = TileType.GRASS;
+      const world = createTestWorld(10, 10, tiles);
+
+      const result = tryDestructTile(world, 0, 0);
+      
+      expect(result).toBe(true);
+      expect(world.tiles[0]).toBe(TileType.GRASS_SAPLINGS);
+    });
+
+    it('should not destruct a non-destructible tile', () => {
+      const tiles = new Array(100).fill(TileType.EMPTY);
+      tiles[0] = TileType.WALL;
+      const world = createTestWorld(10, 10, tiles);
+
+      const result = tryDestructTile(world, 0, 0);
+      
+      expect(result).toBe(false);
+      expect(world.tiles[0]).toBe(TileType.WALL);
+    });
+    
+    it('should return false for out of bounds', () => {
+        const world = createTestWorld(10, 10, new Array(100).fill(TileType.EMPTY));
+        expect(tryDestructTile(world, -1, 0)).toBe(false);
+    });
+  });
+
+  describe('isPlayerOnExit', () => {
+    it('should return true when player is on exit', () => {
+      const world = createTestWorld(10, 10, new Array(100).fill(TileType.EMPTY));
+      world.exit = { x: 5, y: 5 };
+      world.actors.set(1, {
+        id: 1,
+        pos: { x: 5, y: 5 },
+        isPlayer: true
+      } as any);
+
+      expect(isPlayerOnExit(world, 1)).toBe(true);
+    });
+
+    it('should return false when player is not on exit', () => {
+      const world = createTestWorld(10, 10, new Array(100).fill(TileType.EMPTY));
+      world.exit = { x: 5, y: 5 };
+      world.actors.set(1, {
+        id: 1,
+        pos: { x: 4, y: 4 },
+        isPlayer: true
+      } as any);
+
+      expect(isPlayerOnExit(world, 1)).toBe(false);
+    });
+
+    it('should return false when player does not exist', () => {
+      const world = createTestWorld(10, 10, new Array(100).fill(TileType.EMPTY));
+      world.exit = { x: 5, y: 5 };
+      
+      expect(isPlayerOnExit(world, 999)).toBe(false);
+    });
+  });
 });

src/engine/simulation/simulation.ts

@@ -305,36 +305,41 @@ export function decideEnemyAction(w: World, enemy: CombatantActor, player: Comba
   
   // State transitions
   let justAlerted = false;
-  if (canSee && enemy.aiState === "wandering") {
-    // Spotted player! Transition to alerted state
-    enemy.aiState = "alerted";
-    enemy.alertedAt = Date.now();
-    enemy.lastKnownPlayerPos = { ...player.pos };
-    justAlerted = true;
-  } else if (enemy.aiState === "alerted") {
-    // Check if alert period is over (1 second = 1000ms)
-    const alertDuration = 1000;
-    if (Date.now() - (enemy.alertedAt || 0) > alertDuration) {
-      enemy.aiState = "pursuing";
+  if (canSee) {
+    if (enemy.aiState === "wandering" || enemy.aiState === "searching") {
+        // Spotted player (or re-spotted)! Transition to alerted state
+        enemy.aiState = "alerted";
+        enemy.alertedAt = Date.now();
+        enemy.lastKnownPlayerPos = { ...player.pos };
+        justAlerted = true;
+    } else if (enemy.aiState === "pursuing") {
+        // Keep pursuing, update last known
+        enemy.lastKnownPlayerPos = { ...player.pos };
     }
-  } else if (enemy.aiState === "pursuing") {
-    if (canSee) {
-      // Update last known position
-      enemy.lastKnownPlayerPos = { ...player.pos };
-    } else {
-      // Lost sight - check if we've reached last known position
-      if (enemy.lastKnownPlayerPos) {
-        const distToLastKnown = Math.abs(enemy.pos.x - enemy.lastKnownPlayerPos.x) + 
-                                Math.abs(enemy.pos.y - enemy.lastKnownPlayerPos.y);
-        if (distToLastKnown <= 1) {
-          // Reached last known position, return to wandering
-          enemy.aiState = "wandering";
-          enemy.lastKnownPlayerPos = undefined;
+  } else {
+    // Cannot see player
+    if (enemy.aiState === "alerted") {
+         // Check if alert period is over (1 second = 1000ms)
+        const alertDuration = 1000;
+        if (Date.now() - (enemy.alertedAt || 0) > alertDuration) {
+            enemy.aiState = "pursuing";
+        }
+    } else if (enemy.aiState === "pursuing") {
+        // Lost sight while pursuing -> switch to searching
+        enemy.aiState = "searching";
+    } else if (enemy.aiState === "searching") {
+        // Check if reached last known position
+        if (enemy.lastKnownPlayerPos) {
+            const distToLastKnown = Math.abs(enemy.pos.x - enemy.lastKnownPlayerPos.x) + 
+                                    Math.abs(enemy.pos.y - enemy.lastKnownPlayerPos.y);
+            if (distToLastKnown <= 1) {
+                // Reached last known position, return to wandering
+                enemy.aiState = "wandering";
+                enemy.lastKnownPlayerPos = undefined;
+            }
+        } else {
+             enemy.aiState = "wandering";
         }
-      } else {
-        // No last known position, return to wandering
-        enemy.aiState = "wandering";
-      }
     }
   }
   
@@ -344,7 +349,7 @@ export function decideEnemyAction(w: World, enemy: CombatantActor, player: Comba
   }
   
   if (enemy.aiState === "alerted") {
-    // During alert, stay still (or could do small movement)
+    // During alert, stay still
     return { action: { type: "wait" }, justAlerted };
   }