Replace deprecated appdirs with platformdirs, fix config path lookup with non conda-based environments

.github/workflows/workflow.yaml

@@ -48,6 +48,12 @@ jobs:
         run: |
           python -m pip install git+https://github.com/emscripten-forge/pyjs-code-runner --no-deps --ignore-installed
 
+      # Remove after https://github.com/emscripten-forge/pyjs-code-runner/pull/15 is merged.
+      - name: Install appdirs
+        shell: bash -l {0}
+        run: |
+          python -m pip install appdirs
+
       - name: Run pytest
         shell: bash -l {0}
         run: |

empack/pack.py

@@ -7,7 +7,7 @@
 from tempfile import TemporaryDirectory
 from typing import Callable, Optional
 
-from appdirs import user_cache_dir
+from platformdirs import user_cache_dir
 
 from .filter_env import filter_env, filter_pkg, iterate_env_pkg_meta
 from .micromamba_wrapper import create_environment
@@ -16,7 +16,88 @@
 EMPACK_CACHE_DIR = Path(user_cache_dir("empack"))
 PACKED_PACKAGES_CACHE_DIR = EMPACK_CACHE_DIR / "packed_packages_cache"
 PACKED_PACKAGES_CACHE_DIR.mkdir(parents=True, exist_ok=True)
-DEFAULT_CONFIG_PATH = Path(sys.prefix) / "share" / "empack" / "empack_config.yaml"
+
+
+def _do_i_own(path: str | Path) -> bool:
+    """Verify if the current user has write access to the given path. Sourced from
+    https://github.com/jupyter/jupyter_core/blob/fa513c1550bbd1ebcc14a4a79eb8c5d95e3e23c9/jupyter_core/paths.py#L75-L99
+    """
+    # Copyright (c) Jupyter Development Team.
+    # Distributed under the terms of the Modified BSD License.
+
+    # Derived from IPython.utils.path, which is
+    # Copyright (c) IPython Development Team.
+    # Distributed under the terms of the Modified BSD License.
+
+    p = Path(path).resolve()
+
+    while not p.exists() and p != p.parent:
+        p = p.parent
+
+    # simplest check: owner by name
+    # not always implemented or available
+    try:
+        return p.owner() == os.getlogin()
+    except Exception:  # noqa: S110
+        pass
+
+    if hasattr(os, "geteuid"):
+        try:
+            st = p.stat()
+            return st.st_uid == os.geteuid()
+        except (NotImplementedError, OSError):
+            # geteuid not always implemented
+            pass
+
+    # no ownership checks worked, check write access
+    return os.access(p, os.W_OK)
+
+
+def get_config_path() -> Path:
+    """Find the empack configuration file by checking common locations.
+
+    This function checks for the config file in the following order:
+    1. Inside the environment's share directory (conda-style environments)
+    2. Inside a share/ directory next to a virtual environment
+
+    Returns:
+        Path: Location of the empack_config.yaml file
+    """
+    # Copyright (c) Jupyter Development Team.
+    # Distributed under the terms of the Modified BSD License.
+
+    # Derived from IPython.utils.path, which is
+    # Copyright (c) IPython Development Team.
+    # Distributed under the terms of the Modified BSD License.
+
+    # 1. Check for config in environment's share directory. This is applicable
+    # for conda/mamba/micromamba style environments.
+    prefix = None
+    if (
+        "CONDA_PREFIX" in os.environ
+        and sys.prefix.startswith(os.environ["CONDA_PREFIX"])
+        and os.environ.get("CONDA_DEFAULT_ENV", "base") != "base"
+        and _do_i_own(sys.prefix)
+    ):
+        prefix = Path(os.environ["CONDA_PREFIX"])
+    else:
+        prefix = Path(sys.prefix)
+
+    config_path = prefix / "share" / "empack" / "empack_config.yaml"
+    if config_path.exists():
+        return config_path
+
+    # 2. For virtual environments via virtualenv/venv/uv, check if share/ is next
+    # to the environment base directory. This is also applicable for the case
+    # where there's no virtual environment at all (--user install).
+    if sys.prefix != sys.base_prefix and _do_i_own(sys.prefix):
+        venv_parent = Path(sys.prefix).parent
+        parent_share = venv_parent / "share" / "empack" / "empack_config.yaml"
+        if parent_share.exists():
+            return parent_share
+
+
+DEFAULT_CONFIG_PATH = get_config_path()
 
 
 def filename_base_from_meta(pkg_meta):

pyproject.toml

@@ -24,7 +24,7 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
 ]
 dependencies = [
-    "appdirs",
+    "platformdirs",
     "networkx",
     "pyyaml",
     "requests",