feat(hot-reload): Implement HotReloader.reload and reload_all

tests/test_hot_reloader.py

@@ -1,6 +1,9 @@
 from __future__ import annotations
 import pytest
 from src.hot_reloader import HotModule, HotReloader
+from unittest.mock import MagicMock, patch
+import sys
+import types
 
 def test_hot_module_dataclass_fields():
     hm = HotModule(
@@ -32,4 +35,66 @@ def test_hot_reloader_is_error_state():
     HotReloader.HOT_MODULES.clear()
     HotReloader.last_error = None
     HotReloader.is_error_state = False
-    assert HotReloader.is_error_state is False
+    assert HotReloader.is_error_state is False
+
+def test_reload_unknown_module_returns_false():
+    HotReloader.HOT_MODULES.clear()
+    HotReloader.register(HotModule(name="nonexistent_mod", file_path="/nonexistent.py", state_keys=[], delegation_targets=[]))
+    app = MagicMock()
+    result = HotReloader.reload("nonexistent_mod", app)
+    assert result is False
+    assert HotReloader.is_error_state is True
+    assert HotReloader.last_error is not None
+
+def test_reload_success_clears_error_state():
+    HotReloader.HOT_MODULES.clear()
+    test_mod = types.ModuleType("src._test_reload_mod_src")
+    sys.modules["src._test_reload_mod_src"] = test_mod
+    HotReloader.register(HotModule(name="src._test_reload_mod_src", file_path="/fake.py", state_keys=[], delegation_targets=[]))
+    app = MagicMock()
+    HotReloader.is_error_state = True
+    HotReloader.last_error = "previous error"
+    with patch("importlib.reload", return_value=test_mod):
+        result = HotReloader.reload("src._test_reload_mod_src", app)
+    assert result is True
+    assert HotReloader.is_error_state is False
+    assert HotReloader.last_error is None
+    del sys.modules["src._test_reload_mod_src"]
+
+def test_reload_captures_and_restores_state_on_failure():
+    HotReloader.HOT_MODULES.clear()
+    HotReloader.register(HotModule(name="bad_mod", file_path="/bad.py", state_keys=["_test_attr"], delegation_targets=[]))
+    app = MagicMock()
+    app._test_attr = "preserved_value"
+    result = HotReloader.reload("bad_mod", app)
+    assert result is False
+    assert HotReloader.is_error_state is True
+    assert app._test_attr == "preserved_value"
+
+def test_reload_all_success():
+    HotReloader.HOT_MODULES.clear()
+    mod1 = types.ModuleType("hr_test_mod1")
+    mod2 = types.ModuleType("hr_test_mod2")
+    sys.modules["hr_test_mod1"] = mod1
+    sys.modules["hr_test_mod2"] = mod2
+    HotReloader.register(HotModule(name="hr_test_mod1", file_path="/fake1.py", state_keys=[], delegation_targets=[]))
+    HotReloader.register(HotModule(name="hr_test_mod2", file_path="/fake2.py", state_keys=[], delegation_targets=[]))
+    app = MagicMock()
+    with patch("importlib.reload", return_value=mod1):
+        result = HotReloader.reload_all(app)
+    assert result is True
+    assert HotReloader.is_error_state is False
+    del sys.modules["hr_test_mod1"]
+    del sys.modules["hr_test_mod2"]
+
+def test_reload_all_partial_failure():
+    HotReloader.HOT_MODULES.clear()
+    mod1 = types.ModuleType("hr_test_mod1")
+    sys.modules["hr_test_mod1"] = mod1
+    HotReloader.register(HotModule(name="hr_test_mod1", file_path="/fake1.py", state_keys=[], delegation_targets=[]))
+    HotReloader.register(HotModule(name="hr_nonexistent", file_path="/nonexistent.py", state_keys=[], delegation_targets=[]))
+    app = MagicMock()
+    result = HotReloader.reload_all(app)
+    assert result is False
+    assert HotReloader.is_error_state is True
+    del sys.modules["hr_test_mod1"]