Improve configuration management

sphinx/user-guide/configuration.rst

@@ -11,14 +11,52 @@ The configuration can be modified using two functions:
 - :py:func:`config.load_config <vortex.config.load_config>`: Set multiple keys from a TOML file.
 
 The value of a specific key can be queried using
-:py:func:`config.from_confi <vortex.config.from_config>`.  It is also
+:py:func:`config.from_config <vortex.config.from_config>`.  It is also
 possible to print the entire configuration using
-:py:func:`config.print_config <vortex.config.print_config>`.
+:py:func:`config.print_config <vortex.config.print_config>`. If the
+current configuration was read from a file, the corresponding path can
+be read from the value of ``config.file``.
+
+.. code:: toml
+
+   [storage]
+   address = "ftp.domain.com"
+
+
+.. code:: python
+
+   >>> from vortex import config
+   >>> config.load_config("~/.vortex.d/vortex.toml")  # The default
+   >>> config.file
+   PosixPath('/home/user/.vortex.d/vortex.toml')
+   >>> config.from_config("storage", "address")
+   "ftp.domain.com"
+   >>> from_config("storage", "protocol")
+   ConfigurationError: Missing configuration key protocol in section storage
+   >>> config.set_config("storage", "protocol", value="ftp")
+   >>> config.print_config()
+   Section: storage
+    ADDRESS: hendrix.meteo.fr
+    PROTOCOL: ftp
 
 .. seealso::
 
    :doc:`../reference/configuration`
 
+
+Default configuration
+^^^^^^^^^^^^^^^^^^^^^
+
+At import time, ``vortex`` tries to read configuration from a file
+``vortex.toml`` in the current working directory.
+
+If not found, ``vortex`` reads configuration from
+``~/.vortex.d/vortex.toml``.
+
+If the default configuration is not found, *vortex* is left
+unconfigured.
+
+
 ``data-tree``
 ^^^^^^^^^^^^^
 

src/vortex/config.py

@@ -3,6 +3,8 @@
 
 """
 
+import sys
+import types
 from pathlib import Path
 import tomli
 
@@ -17,6 +19,7 @@
 ]
 
 VORTEX_CONFIG = {}
+_PATH = None
 
 logger = loggers.getLogger(__name__)
 
@@ -42,11 +45,12 @@ def load_config(configpath=Path("vortex.toml")):
        # ...
     """
     global VORTEX_CONFIG
+    global _PATH
     configpath = Path(configpath)
     try:
         with configpath.open(mode="rb") as f:
             VORTEX_CONFIG = tomli.load(f)
-        print(f"Successfully read configuration file {configpath.absolute()}")
+            _PATH = configpath.absolute()
     except FileNotFoundError:
         print(
             f"Could not read configuration file {configpath.absolute()} (not found)."
@@ -56,9 +60,12 @@ def load_config(configpath=Path("vortex.toml")):
 
 def print_config():
     """Print configuration (key, value) pairs"""
-    if VORTEX_CONFIG:
-        for k, v in VORTEX_CONFIG.items():
-            print(k.upper(), v)
+    if not VORTEX_CONFIG:
+        return None
+    for section_name, section in VORTEX_CONFIG.items():
+        print(f"Section: {section_name.upper()}")
+        for k, v in section.items():
+            print(f"    {k.upper()}: {v}")
 
 
 def from_config(section, key=None):
@@ -114,3 +121,16 @@ def get_from_config_w_default(section, key, default):
         return from_config(section, key)
     except ConfigurationError:
         return default
+
+
+class _ConfigModule(types.ModuleType):
+    @property
+    def file(self):
+        return _PATH
+
+    @file.setter
+    def file(self, value):
+        raise AttributeError("config.file is read-only")
+
+
+sys.modules[__name__].__class__ = _ConfigModule

tests/test_config.py

@@ -13,6 +13,26 @@
     },
 }
 
+
+@pytest.fixture
+def clean_config():
+    """Save and restore VORTEX_CONFIG and _PATH around a test."""
+    saved_cfg = config.VORTEX_CONFIG.copy()
+    saved_path = config._PATH
+    config.VORTEX_CONFIG = {}
+    config._PATH = None
+    yield
+    config.VORTEX_CONFIG = saved_cfg
+    config._PATH = saved_path
+
+
+@pytest.fixture
+def toml_config_file(tmp_path):
+    p = tmp_path / "vortex.toml"
+    p.write_text('[data-tree]\nrootdir = "/tmp/data"\n')
+    return p
+
+
 def test_section_from_config():
     with pytest.raises(config.ConfigurationError):
         config_section = config.from_config("nonexist")
@@ -45,14 +65,50 @@ def test_is_defined():
 
 
 def test_get_from_config_w_default():
+    assert (
+        config.get_from_config_w_default(
+            "data-tree",
+            "nonexist",
+            "default",
+        )
+        == "default"
+    )
 
     assert config.get_from_config_w_default(
-        "data-tree", "nonexist", "default",
-    ) == "default"
-
-    assert config.get_from_config_w_default(
-        "data-tree", "op-rootdir", "default",
+        "data-tree",
+        "op-rootdir",
+        "default",
     ) == config.from_config("data-tree", "op-rootdir")
-
-
-
+
+
+def test_load_config_populates_config(clean_config, toml_config_file):
+    config.load_config(toml_config_file)
+
+    assert config.VORTEX_CONFIG == {"data-tree": {"rootdir": "/tmp/data"}}
+
+
+def test_load_config_sets_file_property(clean_config, toml_config_file):
+    config.load_config(toml_config_file)
+
+    assert config.file == toml_config_file.absolute()
+
+
+def test_load_config_overrides_existing(clean_config, tmp_path):
+    first = tmp_path / "first.toml"
+    first.write_text('[section-a]\nkey = "value-a"\n')
+    second = tmp_path / "second.toml"
+    second.write_text('[section-b]\nkey = "value-b"\n')
+
+    config.load_config(first)
+    config.load_config(second)
+
+    assert "section-a" not in config.VORTEX_CONFIG
+    assert config.VORTEX_CONFIG == {"section-b": {"key": "value-b"}}
+
+
+def test_load_config_file_not_found(clean_config, tmp_path, capsys):
+    config.load_config(tmp_path / "nonexistent.toml")
+
+    captured = capsys.readouterr()
+    assert "not found" in captured.out
+    assert config.VORTEX_CONFIG == {}