New ConfigManager, Repo, and Worktree

conftest.py

@@ -0,0 +1,20 @@
+"""Fixture setup"""
+
+__all__ = [
+    'cfgman',
+    'baregitrepo',
+    'gitrepo',
+    'verify_pristine_gitconfig_global',
+]
+
+
+from datalad_core.tests.fixtures import (
+    # function-scope temporary, bare Git repo
+    baregitrepo,
+    # function-scope config manager
+    cfgman,
+    # function-scope temporary Git repo
+    gitrepo,
+    # verify no test leave contaminated config behind
+    verify_pristine_gitconfig_global,
+)

datalad_core/config/__init__.py

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+"""Configuration management
+
+This module provides the standard facilities for configuration management,
+query, and update. It is built on `datasalad.settings
+<https://datasalad.readthedocs.io/latest/generated/datasalad.settings.html>`__.
+
+The key piece is the :class:`ConfigManager` that supports querying for
+configuration settings across multiple sources. It also offers a context
+manager to temporarily override particular configuration items.
+
+With the method :meth:`ConfigManager.for_dataset`, a manager instance tailored
+to a specific dataset can be created. A "dataset" in this context is any
+Git repository, with or without an initialized annex, and with or without
+initialization as a DataLad dataset. Such an instance will share all sources
+of the original manager instance, and supports additional sources for the
+scopes of repository-local Git configuration, and branch-committed DataLad
+configuration.
+
+Usage
+-----
+
+Basic usage is more or less identical to that of the ``datasalad.settings``.
+Importantly, and unlike the legacy DataLad approach, no instance of
+:class:`~datalad_core.config.ConfigManager` is provided. Instead, if and when
+such a common instance it needed, it must be obtained by calling
+:func:`get_manager`. This is typically done first by a respective "entrypoint"
+implementation. Subsequent calls will return the same instance.
+
+The same pattern is applied to obtain a common instance of
+:class:`ImplementationDefaults` via :func:`get_defaults`. This instance
+can be used to register defaults for any and all configuration settings
+supported by a particular implementation. This can be done on importing
+the respective modules.
+
+
+.. currentmodule:: datalad_core.config
+.. autosummary::
+   :toctree: generated
+
+   ConfigItem
+   ConfigManager
+   GitConfig
+   SystemGitConfig
+   GlobalGitConfig
+   LocalGitConfig
+   DataladBranchConfig
+   WorktreeGitConfig
+   GitEnvironment
+   ImplementationDefaults
+   UnsetValue
+   get_defaults
+   get_manager
+"""
+
+__all__ = [
+    'ConfigItem',
+    'ConfigManager',
+    'GitConfig',
+    'SystemGitConfig',
+    'GlobalGitConfig',
+    'LocalGitConfig',
+    'DataladBranchConfig',
+    'WorktreeGitConfig',
+    'GitEnvironment',
+    'ImplementationDefaults',
+    'UnsetValue',
+    'get_defaults',
+    'get_manager',
+]
+
+from datasalad.settings import UnsetValue
+
+from .defaults import (
+    ImplementationDefaults,
+    get_defaults,
+)
+from .git import (
+    DataladBranchConfig,
+    GitConfig,
+    GlobalGitConfig,
+    LocalGitConfig,
+    SystemGitConfig,
+    WorktreeGitConfig,
+)
+from .gitenv import GitEnvironment
+from .item import ConfigItem
+from .manager import (
+    ConfigManager,
+    get_manager,
+)

datalad_core/config/defaults.py

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+from __future__ import annotations
+
+from datasalad.settings import (
+    Defaults,
+)
+from datasalad.settings import (
+    UnsetValue as Unset,
+)
+
+from datalad_core.config.item import ConfigItem as Item
+
+
+class ImplementationDefaults(Defaults):
+    """Source for registering implementation defaults of settings
+
+    This is a in-memory only source that is populated by any
+    implementations that want to expose their configuration
+    options."""
+
+    def __str__(self):
+        return 'ImplementationDefaults'
+
+
+__the_defaults: ImplementationDefaults | None = None
+
+
+def get_defaults() -> ImplementationDefaults:
+    """Return a a process-unique `ImplementationDefault` instance
+
+    This function can be used obtain a :class:`ImplementationDefaults`
+    instance for setting and/or getting defaults for settings.
+    """
+    global __the_defaults  # noqa: PLW0603
+    if __the_defaults is None:
+        __the_defaults = ImplementationDefaults()
+        register_defaults_gitcfg(__the_defaults)
+    return __the_defaults
+
+
+def register_defaults_gitcfg(defaults: ImplementationDefaults) -> None:
+    for k, v in _gitcfg.items():
+        defaults[k] = v
+
+
+def anything2bool(val):
+    if val == '':
+        return False
+    if hasattr(val, 'lower'):
+        val = val.lower()
+    if val in {'off', 'no', 'false', '0'} or not bool(val):
+        return False
+    if (
+        val in {'on', 'yes', 'true', True}
+        or (hasattr(val, 'isdigit') and val.isdigit() and int(val))
+        or isinstance(val, int)
+        and val
+    ):
+        return True
+    msg = f'Cannot interpret {val!r} as a boolean'
+    raise ValueError(msg)
+
+
+_gitcfg = {
+    'core.bare': Item(Unset, coercer=anything2bool),
+    'extensions.worktreeConfig': Item(Unset, coercer=anything2bool),
+}