bug: from_json seems to be broken

[mnesarco]

Description of the bug

loading from generated json fails

To Reproduce

mod = loader.load("path/to/x")
s = mod.as_json()
back = Module.from_json(s)

Full traceback

Traceback (most recent call last):
  File "_devel/projects/Marz/FreeCAD/fcdocs/extractor.py", line 46, in <module>
    extract(Path("___fc_root___"), [], Path("FreeCAD.json"))
  File "_devel/projects/Marz/FreeCAD/fcdocs/extractor.py", line 32, in extract
    x = Object.from_json(fc.as_json())
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "_devel/projects/Marz/FreeCAD/fcdocs/.venv/lib/python3.11/site-packages/griffe/_internal/mixins.py", line 247, in from_json
    obj = json.loads(json_string, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "_.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/json/__init__.py", line 359, in loads
    return cls(**kw).decode(s)
           ^^^^^^^^^^^^^^^^^^^
  File "_.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "_.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/json/decoder.py", line 353, in raw_decode
    obj, end = self.scan_once(s, idx)
               ^^^^^^^^^^^^^^^^^^^^^^
  File "_devel/projects/Marz/FreeCAD/fcdocs/.venv/lib/python3.11/site-packages/griffe/_internal/encoders.py", line 367, in json_decoder
    return _loader_map[kind](obj_dict)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "_devel/projects/Marz/FreeCAD/fcdocs/.venv/lib/python3.11/site-packages/griffe/_internal/encoders.py", line 197, in _load_module
    filepath=Path(obj_dict["filepath"]) if "filepath" in obj_dict else None,
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "_.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/pathlib.py", line 871, in __new__
    self = cls._from_parts(args)
           ^^^^^^^^^^^^^^^^^^^^^
  File "_.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/pathlib.py", line 509, in _from_parts
    drv, root, parts = self._parse_args(args)
                       ^^^^^^^^^^^^^^^^^^^^^^
  File "_.local/share/uv/python/cpython-3.11.13-linux-x86_64-gnu/lib/python3.11/pathlib.py", line 493, in _parse_args
    a = os.fspath(a)
        ^^^^^^^^^^^^
TypeError: expected str, bytes or os.PathLike object, not list

Expected behavior

must load the Module back as griffe object.

Environment information

- __System__: Linux-6.14.0-29-generic-x86_64-with-glibc2.39
- __Python__: cpython 3.11.13 (.venv/bin/python3)
- __Environment variables__:
- __Installed packages__:
  - `griffe` v1.14.0

PASTE MARKDOWN OUTPUT HERE

Additional context

[pawamoy]

Thanks for the report 🙂 It looks like from_json() doesn't handle namespace packages (where filepath is a list of directories).

[bswck]

Proper reproduction:

import os

from griffe import GriffeLoader, Object

os.makedirs("ns123", exist_ok=True)

Object.from_json(GriffeLoader().load("ns123").as_json())