Implement get_path and add tests

devchat/namespace.py

@@ -0,0 +1,31 @@
+import os
+from typing import List, Optional
+
+
+class Namespace:
+    def __init__(self, root_path: str,
+                 branches: List[str] = None):
+        """
+        :param root_path: The root path of the namespace.
+        :param branches: The hidden branches with descending order of priority.
+        """
+        self.root_path = root_path
+        self.branches = branches if branches else ['usr', 'org', 'sys']
+
+    def get_path(self, name: str) -> Optional[str]:
+        """
+        :param name: The command name in the namespace.
+        :return: The relative path of the command directory.
+        """
+        if not name:
+            return None
+        # Convert the dot-separated name to a path
+        path = os.path.join(*name.split('.'))
+
+        for branch in self.branches:
+            full_path = os.path.join(self.root_path, branch, path)
+            if os.path.exists(full_path):
+                # If it exists, return the branch/path part
+                return os.path.join(branch, path)
+        # If no existing path is found, return None
+        return None

tests/test_namespace.py

@@ -0,0 +1,26 @@
+import os
+from devchat.namespace import Namespace
+
+
+def test_get_path(tmp_path):
+    # Create a Namespace instance with the temporary directory as the root path
+    namespace = Namespace(str(tmp_path))
+
+    # Test case 1: a path that exists
+    # Create a file in the 'usr' branch
+    os.makedirs(os.path.join(tmp_path, 'usr', 'a', 'b', 'c'), exist_ok=True)
+    assert namespace.get_path('a.b.c') == os.path.join('usr', 'a', 'b', 'c')
+
+    # Test case 2: a path that doesn't exist
+    assert namespace.get_path('d.e.f') is None
+
+    # Test case 3: a path that exists in a later branch
+    # Create a file in the 'sys' branch
+    os.makedirs(os.path.join(tmp_path, 'sys', 'g', 'h', 'i'), exist_ok=True)
+    assert namespace.get_path('g.h.i') == os.path.join('sys', 'g', 'h', 'i')
+
+    # Test case 4: a path in 'usr' overwrites the same in 'sys'
+    # Create the same file in the 'usr' and 'sys' branches
+    os.makedirs(os.path.join(tmp_path, 'usr', 'j', 'k', 'l'), exist_ok=True)
+    os.makedirs(os.path.join(tmp_path, 'sys', 'j', 'k', 'l'), exist_ok=True)
+    assert namespace.get_path('j.k.l') == os.path.join('usr', 'j', 'k', 'l')