diff --git a/Writing-Tests.-.md b/Writing-Tests.-.md
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+# Writing Tests
+
+Guide to creating automated tests for McRogueFace using Python and the automation API.
+
+## Quick Reference
+
+**Test Location:** `tests/` directory (NOT `build/tests/` - that gets shipped!)
+
+**Test Types:**
+1. **Direct Execution** - No game loop, immediate results
+2. **Timer-Based** - Requires rendering/game loop
+
+**Key Tools:**
+- `mcrfpy.automation` - Screenshot and input automation
+- `--headless` flag - Run without display
+- `--exec` flag - Execute specific script
+
+**Format:** See CLAUDE.md "Testing Guidelines" section
+
+---
+
+## Test Type 1: Direct Execution
+
+For tests that don't need rendering or game state.
+
+### Template
+
+```python
+"""Test description goes here."""
+import mcrfpy
+import sys
+
+def test_feature():
+    # Setup
+    scene = mcrfpy.Scene("test")
+    frame = mcrfpy.Frame(pos=(0, 0), size=(100, 100))
+    scene.children.append(frame)
+
+    # Test
+    frame.x = 42
+    assert frame.x == 42, f"Expected 42, got {frame.x}"
+
+    return True
+
+if __name__ == "__main__":
+    try:
+        if test_feature():
+            print("PASS")
+            sys.exit(0)
+    except Exception as e:
+        print(f"FAIL: {e}")
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+```
+
+### Running
+
+```bash
+cd build
+./mcrogueface --headless --exec ../tests/unit/test_myfeature.py
+```
+
+---
+
+## Test Type 2: Timer-Based Tests
+
+For tests requiring rendering, screenshots, or elapsed time.
+
+### Template
+
+```python
+"""Test requiring game loop."""
+import mcrfpy
+from mcrfpy import automation
+import sys
+
+# Setup scene BEFORE game loop starts
+scene = mcrfpy.Scene("test")
+ui = scene.children
+
+frame = mcrfpy.Frame(pos=(100, 100), size=(200, 150),
+                      fill_color=mcrfpy.Color(255, 0, 0))
+ui.append(frame)
+mcrfpy.current_scene = scene
+
+def run_test(timer, runtime):
+    """Timer callback receives (timer_object, runtime_ms)."""
+    automation.screenshot("test_output.png")
+
+    # Verify results
+    assert frame.x == 100
+
+    print("PASS")
+    sys.exit(0)  # MUST exit!
+
+# Schedule test to run after game loop starts
+test_timer = mcrfpy.Timer("test_runner", run_test, 100)
+```
+
+**Important:** Timer callbacks receive `(timer, runtime_ms)`. Screenshots only work after rendering starts.
+
+### Example: Testing Click Events
+
+```python
+import mcrfpy
+from mcrfpy import automation
+import sys
+
+clicks_received = []
+
+scene = mcrfpy.Scene("test")
+frame = mcrfpy.Frame(pos=(100, 100), size=(200, 150),
+                      fill_color=mcrfpy.Color(0, 255, 0))
+
+def on_click(pos, button, action):
+    clicks_received.append((pos, button, action))
+
+frame.on_click = on_click
+scene.children.append(frame)
+mcrfpy.current_scene = scene
+
+def run_test(timer, runtime):
+    # Simulate click on frame center
+    automation.click(200, 175)
+    # Give it a frame to process
+    verify_timer = mcrfpy.Timer("verify", verify_results, 32)
+
+def verify_results(timer, runtime):
+    assert len(clicks_received) > 0, "No clicks received!"
+    pos, button, action = clicks_received[0]
+    print(f"Click received at ({pos.x}, {pos.y})")
+    print("PASS")
+    sys.exit(0)
+
+test_timer = mcrfpy.Timer("test", run_test, 100)
+```
+
+---
+
+## Automation API
+
+### Screenshots
+
+```python
+from mcrfpy import automation
+
+# Take screenshot (synchronous in headless mode)
+automation.screenshot("output.png")
+```
+
+### Mouse Input
+
+```python
+from mcrfpy import automation
+
+automation.click(x, y)         # Left click at position
+automation.move(x, y)          # Move mouse to position
+```
+
+### Keyboard Input
+
+```python
+from mcrfpy import automation
+
+automation.keypress(key_code)  # Simulate key press
+```
+
+---
+
+## Testing Patterns
+
+### Pattern 1: Property Round-Trip
+
+```python
+def test_property_roundtrip():
+    obj = mcrfpy.Frame(pos=(0, 0), size=(100, 100))
+    test_values = [0, 50, 100, 255, 127]
+    for value in test_values:
+        obj.x = value
+        assert obj.x == value, f"Failed for {value}"
+```
+
+### Pattern 2: Exception Testing
+
+```python
+def test_invalid_input():
+    grid = mcrfpy.Grid(grid_size=(10, 10), pos=(0, 0), size=(160, 160))
+    try:
+        grid.at(-1, -1)
+        assert False, "Should have raised exception"
+    except Exception:
+        pass  # Expected
+```
+
+### Pattern 3: Grid Operations
+
+```python
+def test_grid_walkable():
+    grid = mcrfpy.Grid(grid_size=(10, 10), pos=(0, 0), size=(160, 160))
+    grid.at(5, 5).walkable = True
+    assert grid.at(5, 5).walkable == True
+
+    grid.at(5, 5).walkable = False
+    assert grid.at(5, 5).walkable == False
+```
+
+### Pattern 4: Entity Lifecycle
+
+```python
+def test_entity_lifecycle():
+    grid = mcrfpy.Grid(grid_size=(20, 20), pos=(0, 0), size=(320, 320))
+
+    # Create and add
+    entity = mcrfpy.Entity(grid_pos=(5, 5), sprite_index=0)
+    assert entity.grid is None
+    grid.entities.append(entity)
+    assert entity.grid is not None
+
+    # Move
+    entity.grid_x = 10
+    assert entity.grid_x == 10
+
+    # Remove
+    entity.die()
+    assert entity.grid is None
+```
+
+### Pattern 5: Callback Setup
+
+```python
+def test_click_callbacks():
+    frame = mcrfpy.Frame(pos=(100, 100), size=(200, 150))
+    clicks = []
+
+    # on_click receives (pos: Vector, button: MouseButton, action: InputState)
+    def on_click(pos, button, action):
+        if button == mcrfpy.MouseButton.LEFT and action == mcrfpy.InputState.PRESSED:
+            clicks.append((pos.x, pos.y))
+
+    frame.on_click = on_click
+    # on_enter/on_exit receive (pos: Vector)
+    frame.on_enter = lambda pos: None
+    frame.on_exit = lambda pos: None
+```
+
+### Pattern 6: Timer Usage
+
+```python
+def test_timer():
+    fired = [False]
+
+    def on_timer(timer, runtime):
+        fired[0] = True
+
+    t = mcrfpy.Timer("test_timer", on_timer, 100)
+
+    # In headless mode, use step() to advance time
+    mcrfpy.step(0.2)  # 200ms
+    assert fired[0], "Timer should have fired"
+
+    t.stop()  # Clean up
+```
+
+### Pattern 7: Animation Testing
+
+```python
+def test_animation():
+    frame = mcrfpy.Frame(pos=(0, 0), size=(100, 100))
+    frame.animate("x", 500.0, 2.0, mcrfpy.Easing.EASE_IN_OUT)
+
+    # In headless mode, advance time to test
+    mcrfpy.step(1.0)  # Halfway through
+    assert frame.x > 0  # Should have moved
+
+    mcrfpy.step(1.0)  # Complete
+    # frame.x should be at or near 500
+```
+
+---
+
+## Test-Driven Development (TDD)
+
+### TDD Workflow
+
+1. **Write failing test** - Demonstrates the bug/missing feature
+2. **Run test** - Verify it fails
+3. **Implement fix** - Make minimum change to pass
+4. **Run test** - Verify it passes
+5. **Refactor** - Clean up
+6. **Run full suite** - `cd tests && python3 run_tests.py`
+
+---
+
+## Testing Best Practices
+
+### DO:
+
+- **Test one thing at a time** - Each test function covers one behavior
+- **Use descriptive names** - `test_entity_moves_to_valid_position()`
+- **Always exit** - Use `sys.exit(0)` for pass, `sys.exit(1)` for fail
+- **Test edge cases** - Boundaries, empty states, invalid input
+- **Clean up timers** - Call `timer.stop()` when done
+
+### DON'T:
+
+- **Rely on timing** - Use `step()` in headless mode, not `time.sleep()`
+- **Forget sys.exit()** in timer tests - Will hang indefinitely
+- **Test multiple unrelated things** in one test function
+- **Put tests in build/** - They get shipped with the game
+
+---
+
+## Running the Test Suite
+
+```bash
+# Full suite
+cd tests && python3 run_tests.py
+
+# Single test
+cd build && ./mcrogueface --headless --exec ../tests/unit/my_test.py
+
+# Inline test
+cd build && ./mcrogueface --headless -c "import mcrfpy; print('OK')"
+```
+
+---
+
+## Related Documentation
+
+- [[Headless-Mode]] - step() function and headless operation
+- [[Input-and-Events]] - Event handler signatures
+- [[Animation-System]] - Animation testing
+- CLAUDE.md - Testing guidelines section
+
+---
+
+*Last updated: 2026-02-07*
\ No newline at end of file
diff --git a/Writing-Tests.md b/Writing-Tests.md
deleted file mode 100644
index e41fafd..0000000
--- a/Writing-Tests.md
+++ /dev/null
@@ -1,512 +0,0 @@
-# Writing Tests
-
-Guide to creating automated tests for McRogueFace using Python and the automation API.
-
-## Quick Reference
-
-**Test Location:** `tests/` directory (NOT `build/tests/` - that gets shipped!)
-
-**Test Types:**
-1. **Direct Execution** - No game loop, immediate results
-2. **Timer-Based** - Requires rendering/game loop
-
-**Key Tools:**
-- `mcrfpy.automation` - Screenshot and input automation
-- `--headless` flag - Run without display
-- `--exec` flag - Execute specific script
-
-**Format:** See CLAUDE.md "Testing Guidelines" section
-
----
-
-## Test Type 1: Direct Execution
-
-For tests that don't need rendering or game state.
-
-### Template
-
-```python
-#!/usr/bin/env python3
-"""Test description goes here."""
-
-import mcrfpy
-import sys
-
-def test_feature():
-    # Setup
-    obj = mcrfpy.SomeClass()
-    
-    # Test
-    obj.property = 42
-    
-    # Verify
-    assert obj.property == 42, f"Expected 42, got {obj.property}"
-    
-    # More tests...
-    return True
-
-if __name__ == "__main__":
-    try:
-        if test_feature():
-            print("PASS")
-            sys.exit(0)
-        else:
-            print("FAIL")
-            sys.exit(1)
-    except Exception as e:
-        print(f"FAIL: {e}")
-        import traceback
-        traceback.print_exc()
-        sys.exit(1)
-```
-
-### Running
-
-```bash
-cd build
-./mcrogueface --headless --exec ../tests/test_myfeature.py
-```
-
-### Example: Testing Vector Operations
-
-```python
-import mcrfpy
-import sys
-
-def test_vector():
-    # Create vector
-    v = mcrfpy.Vector(3.0, 4.0)
-    
-    # Test properties
-    assert v.x == 3.0
-    assert v.y == 4.0
-    
-    # Test tuple access
-    assert v[0] == 3.0
-    assert v[1] == 4.0
-    
-    # Test modification
-    v.x = 10.0
-    assert v.x == 10.0
-    
-    print("All vector tests passed")
-    return True
-
-if __name__ == "__main__":
-    if test_vector():
-        print("PASS")
-        sys.exit(0)
-    else:
-        print("FAIL")
-        sys.exit(1)
-```
-
----
-
-## Test Type 2: Timer-Based Tests
-
-For tests requiring rendering, screenshots, or game loop.
-
-### Template
-
-```python
-#!/usr/bin/env python3
-"""Test description - requires game loop."""
-
-import mcrfpy
-from mcrfpy import automation
-import sys
-
-# Setup scene BEFORE game loop starts
-mcrfpy.createScene("test")
-
-# Create UI elements
-frame = mcrfpy.Frame(100, 100, 200, 150)
-frame.fill_color = mcrfpy.Color(255, 0, 0)
-mcrfpy.sceneUI("test").append(frame)
-
-# Switch to test scene
-mcrfpy.setScene("test")
-
-def run_test(runtime_ms):
-    """Timer callback - runs AFTER game loop starts."""
-    
-    # Take screenshot
-    automation.screenshot("test_output.png")
-    
-    # Perform interactions
-    automation.click(150, 150)  # Click on frame
-    
-    # Verify results
-    # ... check state, take more screenshots, etc ...
-    
-    # Report results
-    print("PASS")
-    sys.exit(0)  # MUST exit!
-
-# Schedule test to run after game loop starts
-mcrfpy.setTimer("test_runner", run_test, 100)  # 100ms delay
-```
-
-### Running
-
-```bash
-cd build
-./mcrogueface --headless --exec ../tests/test_rendering.py
-```
-
-**Important:** Timer callbacks are essential! Screenshots only work after rendering starts.
-
-### Example: Testing Click Events
-
-```python
-import mcrfpy
-from mcrfpy import automation
-import sys
-
-# Track clicks
-clicks_received = []
-
-def on_frame_click(x, y, button, state):
-    clicks_received.append((x, y, button, state))
-
-# Setup scene
-mcrfpy.createScene("test")
-
-frame = mcrfpy.Frame(100, 100, 200, 150)
-frame.fill_color = mcrfpy.Color(0, 255, 0)
-frame.click = on_frame_click
-
-mcrfpy.sceneUI("test").append(frame)
-mcrfpy.setScene("test")
-
-def run_test(runtime_ms):
-    # Simulate click on frame center
-    automation.click(200, 175)
-    
-    # Give it a frame to process
-    mcrfpy.setTimer("verify", verify_results, 32)
-
-def verify_results(runtime_ms):
-    # Check click was received
-    assert len(clicks_received) > 0, "No clicks received!"
-    
-    x, y, button, state = clicks_received[0]
-    assert button == 1, f"Wrong button: {button}"
-    assert state == True, "Wrong state"
-    
-    print(f"Click received at ({x}, {y})")
-    print("PASS")
-    sys.exit(0)
-
-mcrfpy.setTimer("test", run_test, 100)
-```
-
----
-
-## Automation API
-
-### Screenshots
-
-```python
-from mcrfpy import automation
-
-# Take screenshot
-automation.screenshot("output.png")
-
-# Screenshots saved to current directory
-# Use for visual regression testing
-```
-
-### Mouse Input
-
-```python
-from mcrfpy import automation
-
-# Click at position
-automation.click(x, y, button=1)  # button: 1=left, 2=middle, 3=right
-
-# Move mouse
-automation.move(x, y)
-```
-
-### Keyboard Input
-
-```python
-from mcrfpy import automation
-
-# Key press
-automation.keypress(key_code, pressed=True)
-
-# Key release
-automation.keypress(key_code, pressed=False)
-```
-
-**Key codes:** See `mcrfpy.Key.*` constants
-
----
-
-## Test-Driven Development (TDD)
-
-### TDD Workflow
-
-1. **Write failing test** - Demonstrates the bug/missing feature
-2. **Run test** - Verify it fails
-3. **Implement fix** - Make minimum change to pass
-4. **Run test** - Verify it passes
-5. **Refactor** - Clean up if needed
-6. **Run test** - Verify still passes
-
-### Example: TDD for New Feature
-
-**Step 1: Write failing test**
-
-`tests/test_sprite_rotation.py`:
-```python
-import mcrfpy
-
-def test_sprite_rotation():
-    sprite = mcrfpy.Sprite("test.png", 0, 0)
-    
-    # This should work but doesn't yet
-    sprite.rotation = 90
-    assert sprite.rotation == 90
-    
-    return True
-
-if __name__ == "__main__":
-    if test_sprite_rotation():
-        print("PASS")
-    else:
-        print("FAIL")
-```
-
-**Step 2: Run test - it fails**
-
-```bash
-$ ./mcrogueface --headless --exec tests/test_sprite_rotation.py
-AttributeError: 'Sprite' object has no attribute 'rotation'
-FAIL
-```
-
-**Step 3: Implement feature**
-
-Add `rotation` property to `src/UISprite.cpp` (see [[Adding-Python-Bindings]])
-
-**Step 4: Run test - it passes**
-
-```bash
-$ ./mcrogueface --headless --exec tests/test_sprite_rotation.py
-PASS
-```
-
----
-
-## Testing Best Practices
-
-### DO:
-
-✅ **Test one thing at a time**
-```python
-def test_grid_walkable_setter():
-    grid = mcrfpy.Grid(10, 10, 16, 16)
-    grid.walkable((5, 5), True)
-    # Test only walkable setter, nothing else
-```
-
-✅ **Use descriptive test names**
-```python
-# Good
-def test_entity_moves_to_valid_position()
-
-# Bad
-def test1()
-```
-
-✅ **Clean up after tests**
-```python
-def test_feature():
-    # Setup
-    obj = create_test_object()
-    
-    try:
-        # Test
-        obj.do_thing()
-    finally:
-        # Cleanup
-        obj.cleanup()
-```
-
-✅ **Test edge cases**
-```python
-def test_grid_bounds():
-    grid = mcrfpy.Grid(10, 10, 16, 16)
-    
-    # Test boundaries
-    grid.at((0, 0))  # Min
-    grid.at((9, 9))  # Max
-    
-    # Test out of bounds
-    try:
-        grid.at((10, 10))
-        assert False, "Should have raised exception"
-    except ValueError:
-        pass  # Expected
-```
-
-### DON'T:
-
-❌ **Test multiple unrelated things**
-```python
-# Bad - testing grid, entity, AND animation
-def test_everything():
-    grid = mcrfpy.Grid(10, 10, 16, 16)
-    entity = mcrfpy.Entity(5, 5, 0)
-    mcrfpy.animate(entity, "x", 10, 1000, "linear")
-    # Too much!
-```
-
-❌ **Forget to exit in timer-based tests**
-```python
-def run_test(runtime_ms):
-    automation.screenshot("test.png")
-    print("PASS")
-    # MISSING: sys.exit(0) - will hang!
-```
-
-❌ **Rely on timing**
-```python
-# Bad - fragile
-time.sleep(0.5)  # Hope animation finished
-assert entity.x == 100
-
-# Good - check state
-while entity.x < 100 and timeout < 1000:
-    time.sleep(0.016)
-    timeout += 16
-assert entity.x == 100
-```
-
----
-
-## Common Testing Patterns
-
-### Pattern 1: Property Round-Trip
-
-```python
-def test_property_roundtrip():
-    obj = mcrfpy.Frame(0, 0, 100, 100)
-    
-    # Set various values
-    test_values = [0, 50, 100, 255, 127]
-    
-    for value in test_values:
-        obj.x = value
-        assert obj.x == value, f"Failed for {value}"
-```
-
-### Pattern 2: Visual Regression
-
-```python
-def run_test(runtime_ms):
-    # Render scene
-    automation.screenshot("current.png")
-    
-    # Compare with golden image
-    # (Manual comparison or use image diff tool)
-    
-    print("Check current.png against golden/expected.png")
-    sys.exit(0)
-```
-
-### Pattern 3: Exception Testing
-
-```python
-def test_invalid_input():
-    grid = mcrfpy.Grid(10, 10, 16, 16)
-    
-    # Test exception is raised
-    try:
-        grid.at((-1, -1))  # Invalid coords
-        assert False, "Should have raised ValueError"
-    except ValueError as e:
-        assert "out of bounds" in str(e).lower()
-```
-
-### Pattern 4: State Machine Testing
-
-```python
-def test_entity_states():
-    entity = mcrfpy.Entity(0, 0, 0)
-    
-    # Initial state
-    assert entity.state == "idle"
-    
-    # Transition
-    entity.attack()
-    assert entity.state == "attacking"
-    
-    # Complete action
-    entity.finish_attack()
-    assert entity.state == "idle"
-```
-
----
-
-## Debugging Failed Tests
-
-### Get More Information
-
-```python
-def test_feature():
-    try:
-        obj.do_thing()
-    except Exception as e:
-        print(f"Exception: {e}")
-        print(f"Object state: {obj}")
-        print(f"Type: {type(obj)}")
-        raise  # Re-raise to fail test
-```
-
-### Visual Debugging
-
-```python
-def run_test(runtime_ms):
-    # Take screenshot before action
-    automation.screenshot("before.png")
-    
-    # Perform action
-    do_something()
-    
-    # Take screenshot after
-    automation.screenshot("after.png")
-    
-    # Now you can compare visually
-```
-
-### Print Debugging
-
-```python
-def test_complex_operation():
-    print("Starting test...")
-    
-    obj = create_object()
-    print(f"Created: {obj}")
-    
-    result = obj.process()
-    print(f"Result: {result}")
-    
-    assert result == expected
-```
-
----
-
-## Related Documentation
-
-- CLAUDE.md - Testing guidelines section
-- [[Performance-Optimization-Workflow]] - Creating benchmarks
-- `tests/` directory - Example tests
-
-**Testing Pattern Examples:**
-- `tests/test_grid_operations.py` - Direct execution
-- `tests/issue_78_middle_click_test.py` - Timer-based with automation
\ No newline at end of file