test(coverage): add FuzzyAnchor and HistoryManager unit tests

- test_fuzzy_anchor.py: 6 tests for fuzzy slice resolution
- test_history_manager.py: 8 tests for undo/redo and UISnapshot roundtrip

conductor/tracks/phase6_review_20260510/plan.md

@@ -7,7 +7,7 @@
 - [x] Task: Conductor - User Manual Verification 'Phase 1' (Protocol in workflow.md)
 
 ## Phase 2: Feature Coverage (Core Logic)
-- [~] Task: Write unit tests for C++ AST Tree Masking logic using samples from `gencpp/base/components`.
+- [x] Task: Write unit tests for C++ AST Tree Masking logic using samples from `gencpp/base/components`.
 - [ ] Task: Write unit tests for 'Fuzzy Anchor' resolution across simulated file edits.
 - [ ] Task: Write unit tests for `HistoryManager` context snapshot roundtrips.
 - [ ] Task: Conductor - User Manual Verification 'Phase 2' (Protocol in workflow.md)

tests/test_fuzzy_anchor.py

@@ -0,0 +1,59 @@
+import pytest
+from src.fuzzy_anchor import FuzzyAnchor
+
+
+class TestFuzzyAnchor:
+    def test_create_slice_basic(self):
+        text = "line0\nline1\nline2\nline3\nline4\n"
+        result = FuzzyAnchor.create_slice(text, 2, 4)
+        assert "start_line" in result
+        assert "end_line" in result
+        assert "content_hash" in result
+        assert "start_context" in result
+        assert "end_context" in result
+        assert result["start_line"] == 2
+        assert result["end_line"] == 4
+        assert result["start_context"] == result["end_context"]
+
+    def test_resolve_slice_exact_match(self):
+        text = "line0\nline1\nline2\nline3\nline4\n"
+        slc = FuzzyAnchor.create_slice(text, 2, 4)
+        result = FuzzyAnchor.resolve_slice(text, slc)
+        assert result is not None
+        start, end = result
+        assert start == 2
+        assert end == 4
+
+    def test_resolve_slice_line_inserted_before(self):
+        original = "line0\nline1\nline2\nline3\nline4\n"
+        modified = "NEW\nline0\nline1\nline2\nline3\nline4\n"
+        slc = FuzzyAnchor.create_slice(original, 2, 4)
+        result = FuzzyAnchor.resolve_slice(modified, slc)
+        assert result is not None
+        start, end = result
+        assert start == 3
+        assert end == 5
+
+    def test_resolve_slice_line_deleted_before_returns_none(self):
+        original = "line0\nline1\nline2\nline3\nline4\n"
+        modified = "line0\nline2\nline3\nline4\n"
+        slc = FuzzyAnchor.create_slice(original, 2, 4)
+        result = FuzzyAnchor.resolve_slice(modified, slc)
+        assert result is None
+
+    def test_resolve_slice_multiple_lines_changed(self):
+        original = "line0\nline1\nline2\nline3\nline4\n"
+        modified = "a\nb\nc\nd\ne\nline0\nline1\nline2\nline3\nline4\n"
+        slc = FuzzyAnchor.create_slice(original, 1, 2)
+        result = FuzzyAnchor.resolve_slice(modified, slc)
+        assert result is not None
+        start, end = result
+        assert start == 6
+        assert end == 7
+
+    def test_resolve_slice_anchor_mismatch_returns_none(self):
+        original = "alpha\nbeta\ngamma\ndelta\nepsilon\n"
+        modified = "foo\nbar\nbaz\ndelta\nepsilon\n"
+        slc = FuzzyAnchor.create_slice(original, 2, 3)
+        result = FuzzyAnchor.resolve_slice(modified, slc)
+        assert result is None

tests/test_history_manager.py

@@ -0,0 +1,97 @@
+import pytest
+from src.history import HistoryManager, UISnapshot
+
+
+class TestHistoryManager:
+    def test_push_and_undo(self):
+        hm = HistoryManager(max_capacity=10)
+        hm.push({"value": 1}, "initial")
+        hm.push({"value": 2}, "change to 2")
+        assert hm.can_undo is True
+        result = hm.undo(current_state={"value": 2})
+        assert result is not None
+        assert result.state["value"] == 2
+        assert hm.can_undo is True
+
+    def test_undo_and_redo(self):
+        hm = HistoryManager(max_capacity=10)
+        hm.push({"value": 1}, "initial")
+        hm.push({"value": 2}, "change to 2")
+        assert hm.can_redo is False
+        hm.undo(current_state={"value": 2})
+        assert hm.can_redo is True
+        redone = hm.redo(current_state={"value": 1})
+        assert redone is not None
+        assert redone.state["value"] == 2
+
+    def test_undo_no_history_returns_none(self):
+        hm = HistoryManager(max_capacity=10)
+        assert hm.can_undo is False
+        result = hm.undo(current_state={"value": 1})
+        assert result is None
+
+    def test_redo_no_history_returns_none(self):
+        hm = HistoryManager(max_capacity=10)
+        assert hm.can_redo is False
+        result = hm.redo(current_state={"value": 1})
+        assert result is None
+
+    def test_jump_to_undo(self):
+        hm = HistoryManager(max_capacity=10)
+        hm.push({"value": 1}, "initial")
+        hm.push({"value": 2}, "change to 2")
+        hm.push({"value": 3}, "change to 3")
+        result = hm.jump_to_undo(0, current_state={"value": 3})
+        assert result is not None
+        assert result.state["value"] == 1
+        assert hm.can_redo is True
+
+    def test_get_history_returns_descriptions(self):
+        hm = HistoryManager(max_capacity=10)
+        hm.push({"value": 1}, "first")
+        hm.push({"value": 2}, "second")
+        hm.push({"value": 3}, "third")
+        history = hm.get_history()
+        assert len(history) == 3
+        assert history[0]["description"] == "first"
+        assert history[1]["description"] == "second"
+        assert "timestamp" in history[0]
+
+    def test_snapshot_roundtrip(self):
+        snap = UISnapshot(
+            ai_input="test input",
+            project_system_prompt="project prompt",
+            global_system_prompt="global prompt",
+            base_system_prompt="base prompt",
+            use_default_base_prompt=True,
+            temperature=0.5,
+            top_p=0.9,
+            max_tokens=8192,
+            auto_add_history=True,
+            disc_entries=[{"role": "user", "content": "hello"}],
+            files=[{"path": "a.txt"}],
+            screenshots=["screenshot.png"],
+        )
+        d = snap.to_dict()
+        restored = UISnapshot.from_dict(d)
+        assert restored.ai_input == snap.ai_input
+        assert restored.project_system_prompt == snap.project_system_prompt
+        assert restored.global_system_prompt == snap.global_system_prompt
+        assert restored.base_system_prompt == snap.base_system_prompt
+        assert restored.use_default_base_prompt == snap.use_default_base_prompt
+        assert restored.temperature == snap.temperature
+        assert restored.top_p == snap.top_p
+        assert restored.max_tokens == snap.max_tokens
+        assert restored.auto_add_history == snap.auto_add_history
+        assert restored.disc_entries == snap.disc_entries
+        assert restored.files == snap.files
+        assert restored.screenshots == snap.screenshots
+
+    def test_push_clears_redo_stack(self):
+        hm = HistoryManager(max_capacity=10)
+        hm.push({"value": 1}, "initial")
+        hm.push({"value": 2}, "change to 2")
+        hm.undo(current_state={"value": 2})
+        assert hm.can_redo is True
+        hm.push({"value": 3}, "change to 3")
+        assert hm.can_redo is False