Initial release: cd-browser v0.1.0

src/app/filesystem.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from pathlib import Path
+
+
+@dataclass(frozen=True, slots=True)
+class DirectoryEntry:
+    """Directory metadata used by the navigator layer."""
+
+    name: str
+    path: Path
+    has_children: bool
+
+
+def list_directories(path: Path) -> list[DirectoryEntry]:
+    """Return direct child directories sorted by name."""
+
+    directory_path = path.expanduser().resolve()
+    entries: list[DirectoryEntry] = []
+
+    for child in directory_path.iterdir():
+        if child.is_dir():
+            entries.append(
+                DirectoryEntry(
+                    name=child.name,
+                    path=child,
+                    has_children=has_subdirectories(child),
+                )
+            )
+
+    return sorted(entries, key=lambda entry: entry.name.casefold())
+
+
+def has_subdirectories(path: Path) -> bool:
+    """Return whether the directory contains at least one subdirectory."""
+
+    directory_path = path.expanduser().resolve()
+
+    return any(child.is_dir() for child in directory_path.iterdir())