Fix #688: routes/controllers auto-import crash when app is installed as a package

blacksheep/utils/meta.py

@@ -15,6 +15,22 @@ def get_parent_file():
         return ""
 
 
+def _get_dotted_path(root_path: Path) -> str:
+    """
+    Builds the dotted module path for a package folder by walking up its
+    parent directories while they contain an `__init__.py` file, so the
+    package can be imported by its fully qualified name regardless of the
+    current working directory of the running process.
+    """
+    root_path = root_path.resolve()
+    parts = [root_path.name]
+    current = root_path.parent
+    while (current / "__init__.py").is_file():
+        parts.append(current.name)
+        current = current.parent
+    return ".".join(reversed(parts))
+
+
 def import_child_modules(root_path: Path):
     """
     Import automatically all modules defined
@@ -26,7 +42,7 @@ def import_child_modules(root_path: Path):
         for f in glob.glob(path + "/*.py")
         if not os.path.basename(f).startswith("_")
     ]
-    stripped_path = os.path.relpath(path).replace("/", ".").replace("\\", ".")
+    stripped_path = _get_dotted_path(root_path)
     for module in modules:
         __import__(stripped_path + "." + module)
 

tests/test_utils.py

@@ -1,8 +1,10 @@
+import sys
 from typing import AnyStr, Sequence
 
 import pytest
 
 from blacksheep.utils import ensure_bytes, ensure_str, join_fragments
+from blacksheep.utils.meta import import_child_modules
 
 
 @pytest.mark.parametrize(
@@ -45,3 +47,38 @@ def test_ensure_bytes_throws_for_invalid_value():
 def test_ensure_str_throws_for_invalid_value():
     with pytest.raises(ValueError):
         ensure_str(True)  # type: ignore
+
+
+def test_import_child_modules_independent_of_cwd(tmp_path, monkeypatch):
+    """
+    import_child_modules must resolve the dotted module path of a package
+    folder from its own location on disk, not from the current working
+    directory of the process. This reproduces the crash reported when a
+    blacksheep app is installed as a package (e.g. with `uv tool install`)
+    and started from an unrelated working directory: os.getcwd()-based
+    relative paths produced bogus dotted paths such as ".local.share...",
+    raising ModuleNotFoundError.
+    """
+    package_root = tmp_path / "myapp_pkg"
+    package = package_root / "myapp"
+    routes_folder = package / "routes"
+    routes_folder.mkdir(parents=True)
+
+    (package / "__init__.py").write_text("")
+    (routes_folder / "__init__.py").write_text("")
+    (routes_folder / "home.py").write_text("imported = True\n")
+
+    unrelated_cwd = tmp_path / "somewhere_else"
+    unrelated_cwd.mkdir()
+
+    monkeypatch.chdir(unrelated_cwd)
+    monkeypatch.syspath_prepend(str(package_root))
+
+    try:
+        import_child_modules(routes_folder)
+        assert "myapp.routes.home" in sys.modules
+        assert sys.modules["myapp.routes.home"].imported is True
+    finally:
+        for name in list(sys.modules):
+            if name == "myapp" or name.startswith("myapp."):
+                del sys.modules[name]