checkpoint: 0.3.0 ui header, history persistence and history filter

tests/test_history.py

@@ -2,7 +2,7 @@ from pathlib import Path
 
 import pytest
 
-from app.history import SessionHistory
+from app.history import SessionHistory, default_history_path
 
 
 def test_visit_records_current_directory(tmp_path: Path) -> None:
@@ -82,3 +82,48 @@ def test_select_raises_for_invalid_index() -> None:
 
     with pytest.raises(IndexError):
         history.select(0)
+
+
+def test_persistent_history_loads_entries_from_disk(tmp_path: Path) -> None:
+    first = tmp_path / "first"
+    second = tmp_path / "second"
+    for directory in (first, second):
+        directory.mkdir()
+    history_file = tmp_path / "history.txt"
+    history_file.write_text(f"{first}\n{second}\n", encoding="utf-8")
+
+    history = SessionHistory.persistent(storage_path=history_file)
+
+    assert history.entries() == (first.resolve(), second.resolve())
+    assert history.current == second.resolve()
+
+
+def test_persistent_history_visit_writes_to_disk_and_applies_limit(
+    tmp_path: Path,
+) -> None:
+    first = tmp_path / "first"
+    second = tmp_path / "second"
+    third = tmp_path / "third"
+    for directory in (first, second, third):
+        directory.mkdir()
+    history_file = tmp_path / "state" / "history.txt"
+
+    history = SessionHistory.persistent(storage_path=history_file, max_entries=2)
+    history.visit(first)
+    history.visit(second)
+    history.visit(third)
+
+    assert history.entries() == (second.resolve(), third.resolve())
+    assert history_file.read_text(encoding="utf-8").splitlines() == [
+        str(second.resolve()),
+        str(third.resolve()),
+    ]
+
+
+def test_default_history_path_uses_override_env(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+) -> None:
+    override = tmp_path / "custom-history.txt"
+    monkeypatch.setenv("CD_BROWSER_HISTORY_FILE", str(override))
+
+    assert default_history_path() == override