feat: default decorator sections (#123)

* feat: default decorator sections

* chore: add test comment

tests/config.json

@@ -1,5 +1,10 @@
 {
     "arg1": "stuff",
     "opt1": "things",
-    "opt2": "nothing"
+    "opt2": "nothing", 
+    "simple_app": {
+        "arg1": "stuff2",
+        "opt1": "things2",
+        "opt2": "nothing2" 
+    }
 }

tests/config.toml

@@ -1,3 +1,8 @@
 arg1 = "stuff"
 opt1 = "things"
-opt2 = "nothing"
+opt2 = "nothing"
+
+[simple_app]
+arg1 = "stuff2"
+opt1 = "things2"
+opt2 = "nothing2"

tests/config.yml

@@ -1,3 +1,8 @@
 arg1: stuff
 opt1: things
-opt2: nothing
+opt2: nothing
+
+simple_app:
+  arg1: stuff2
+  opt1: things2
+  opt2: nothing2

tests/test_example.py

@@ -217,6 +217,46 @@ def test_simple_example_decorated_default(simple_app_decorated, confs):
     assert "No such file" in result.stdout, f"Wrong error message for {conf}"
 
 
+@pytest.mark.parametrize("confs", CONFS, ids=str)
+def test_simple_example_decorated_section(simple_app_decorated, confs):
+    """Test Simple YAML app (decorator)."""
+
+    conf, _, dec = confs
+
+    # skip tests that won't work
+    if conf.split(".")[-1] in ["ini", "env"]:
+        return
+
+    _app = simple_app_decorated(dec, section=["simple_app"])
+
+    result = RUNNER.invoke(_app, ["--help"])
+    assert (
+        result.exit_code == 0
+    ), f"Couldn't get to `--help` for {conf}\n\n{result.stdout}"
+
+    result = RUNNER.invoke(_app, ["--config", conf])
+    assert result.exit_code == 0, f"Loading failed for {conf}\n\n{result.stdout}"
+    assert (
+        result.stdout.strip() == "things2 nothing2 stuff2"
+    ), f"Unexpected output for {conf}"
+
+    result = RUNNER.invoke(_app, ["--config", conf, "others2"])
+    assert result.exit_code == 0, f"Loading failed for {conf}\n\n{result.stdout}"
+    assert (
+        result.stdout.strip() == "things2 nothing2 others2"
+    ), f"Unexpected output for {conf}"
+
+    result = RUNNER.invoke(_app, ["--config", conf, "--opt1", "people2"])
+    assert result.exit_code == 0, f"Loading failed for {conf}\n\n{result.stdout}"
+    assert (
+        result.stdout.strip() == "people2 nothing2 stuff2"
+    ), f"Unexpected output for {conf}"
+
+    result = RUNNER.invoke(_app, ["--config", conf + ".non_existent"])
+    assert result.exit_code != 0, f"Should have failed for {conf}\n\n{result.stdout}"
+    assert "No such file" in result.stdout, f"Wrong error message for {conf}"
+
+
 def test_pyproject_example(simple_app):
     """Test pyproject example."""
 

typer_config/decorators.py

@@ -9,13 +9,7 @@
 
 from typer import Option
 
-from .callbacks import (
-    conf_callback_factory,
-    dotenv_conf_callback,
-    json_conf_callback,
-    toml_conf_callback,
-    yaml_conf_callback,
-)
+from .callbacks import conf_callback_factory
 from .dumpers import json_dumper, toml_dumper, yaml_dumper
 from .loaders import (
     dotenv_loader,
@@ -25,10 +19,10 @@
     toml_loader,
     yaml_loader,
 )
+from .utils import get_dict_section
 
 if TYPE_CHECKING:  # pragma: no cover
     from .__typing import (
-        ConfigDict,
         ConfigDumper,
         ConfigParameterCallback,
         FilePath,
@@ -106,6 +100,7 @@ def wrapped(*args, **kwargs):  # noqa: ANN202,ANN002,ANN003
 
 # default decorators
 def use_json_config(
+    section: Optional[List[str]] = None,
     param_name: TyperParameterName = "config",
     param_help: str = "Configuration file.",
     default_value: Optional[TyperParameterValue] = None,
@@ -126,6 +121,8 @@ def main(...):
         ```
 
     Args:
+        section (List[str], optional): List of nested sections to access in the config.
+            Defaults to None.
         param_name (TyperParameterName, optional): name of config parameter.
             Defaults to "config".
         param_help (str, optional): config parameter help string.
@@ -137,23 +134,24 @@ def main(...):
         TyperCommandDecorator: decorator to apply to command
     """
 
-    if default_value is not None:
-        callback = conf_callback_factory(
-            loader_transformer(
-                json_loader,
-                loader_conditional=lambda param_value: param_value,
-                param_transformer=lambda param_value: param_value
-                if param_value
-                else default_value,
+    callback = conf_callback_factory(
+        loader_transformer(
+            json_loader,
+            loader_conditional=lambda param_value: param_value,
+            param_transformer=(
+                lambda param_value: param_value if param_value else default_value
             )
+            if default_value is not None
+            else None,
+            config_transformer=lambda config: get_dict_section(config, section),
         )
-    else:
-        callback = json_conf_callback
+    )
 
     return use_config(callback=callback, param_name=param_name, param_help=param_help)
 
 
 def use_yaml_config(
+    section: Optional[List[str]] = None,
     param_name: TyperParameterName = "config",
     param_help: str = "Configuration file.",
     default_value: Optional[TyperParameterValue] = None,
@@ -174,6 +172,8 @@ def main(...):
         ```
 
     Args:
+        section (List[str], optional): List of nested sections to access in the config.
+            Defaults to None.
         param_name (str, optional): name of config parameter. Defaults to "config".
         param_help (str, optional): config parameter help string.
             Defaults to "Configuration file.".
@@ -184,23 +184,24 @@ def main(...):
         TyperCommandDecorator: decorator to apply to command
     """
 
-    if default_value is not None:
-        callback = conf_callback_factory(
-            loader_transformer(
-                yaml_loader,
-                loader_conditional=lambda param_value: param_value,
-                param_transformer=lambda param_value: param_value
-                if param_value
-                else default_value,
+    callback = conf_callback_factory(
+        loader_transformer(
+            yaml_loader,
+            loader_conditional=lambda param_value: param_value,
+            param_transformer=(
+                lambda param_value: param_value if param_value else default_value
             )
+            if default_value is not None
+            else None,
+            config_transformer=lambda config: get_dict_section(config, section),
         )
-    else:
-        callback = yaml_conf_callback
+    )
 
     return use_config(callback=callback, param_name=param_name, param_help=param_help)
 
 
 def use_toml_config(
+    section: Optional[List[str]] = None,
     param_name: TyperParameterName = "config",
     param_help: str = "Configuration file.",
     default_value: Optional[TyperParameterValue] = None,
@@ -221,6 +222,8 @@ def main(...):
         ```
 
     Args:
+        section (List[str], optional): List of nested sections to access in the config.
+            Defaults to None.
         param_name (str, optional): name of config parameter. Defaults to "config".
         param_help (str, optional): config parameter help string.
             Defaults to "Configuration file.".
@@ -231,23 +234,24 @@ def main(...):
         TyperCommandDecorator: decorator to apply to command
     """
 
-    if default_value is not None:
-        callback = conf_callback_factory(
-            loader_transformer(
-                toml_loader,
-                loader_conditional=lambda param_value: param_value,
-                param_transformer=lambda param_value: param_value
-                if param_value
-                else default_value,
+    callback = conf_callback_factory(
+        loader_transformer(
+            toml_loader,
+            loader_conditional=lambda param_value: param_value,
+            param_transformer=(
+                lambda param_value: param_value if param_value else default_value
             )
+            if default_value is not None
+            else None,
+            config_transformer=lambda config: get_dict_section(config, section),
         )
-    else:
-        callback = toml_conf_callback
+    )
 
     return use_config(callback=callback, param_name=param_name, param_help=param_help)
 
 
 def use_dotenv_config(
+    section: Optional[List[str]] = None,
     param_name: TyperParameterName = "config",
     param_help: str = "Configuration file.",
     default_value: Optional[TyperParameterValue] = None,
@@ -268,6 +272,8 @@ def main(...):
         ```
 
     Args:
+        section (List[str], optional): List of nested sections to access in the config.
+            Defaults to None.
         param_name (str, optional): name of config parameter. Defaults to "config".
         param_help (str, optional): config parameter help string.
             Defaults to "Configuration file.".
@@ -278,18 +284,18 @@ def main(...):
         TyperCommandDecorator: decorator to apply to command
     """
 
-    if default_value is not None:
-        callback = conf_callback_factory(
-            loader_transformer(
-                dotenv_loader,
-                loader_conditional=lambda param_value: param_value,
-                param_transformer=lambda param_value: param_value
-                if param_value
-                else default_value,
+    callback = conf_callback_factory(
+        loader_transformer(
+            dotenv_loader,
+            loader_conditional=lambda param_value: param_value,
+            param_transformer=(
+                lambda param_value: param_value if param_value else default_value
             )
+            if default_value is not None
+            else None,
+            config_transformer=lambda config: get_dict_section(config, section),
         )
-    else:
-        callback = dotenv_conf_callback
+    )
 
     return use_config(callback=callback, param_name=param_name, param_help=param_help)
 
@@ -327,31 +333,18 @@ def main(...):
         TyperCommandDecorator: decorator to apply to command
     """
 
-    def _get_section(_section: List[str], config: ConfigDict) -> ConfigDict:
-        for sect in _section:
-            config = config.get(sect, {})
-
-        return config
-
-    if default_value is not None:
-        callback = conf_callback_factory(
-            loader_transformer(
-                ini_loader,
-                loader_conditional=lambda param_value: param_value,
-                param_transformer=lambda param_value: param_value
-                if param_value
-                else default_value,
-                config_transformer=lambda config: _get_section(section, config),
-            )
-        )
-    else:
-        callback = conf_callback_factory(
-            loader_transformer(
-                ini_loader,
-                loader_conditional=lambda param_value: param_value,
-                config_transformer=lambda config: _get_section(section, config),
+    callback = conf_callback_factory(
+        loader_transformer(
+            ini_loader,
+            loader_conditional=lambda param_value: param_value,
+            param_transformer=(
+                lambda param_value: param_value if param_value else default_value
             )
+            if default_value is not None
+            else None,
+            config_transformer=lambda config: get_dict_section(config, section),
         )
+    )
 
     return use_config(callback=callback, param_name=param_name, param_help=param_help)
 

typer_config/utils.py

@@ -0,0 +1,23 @@
+"""Utilities."""
+from __future__ import annotations
+
+from typing import Any, Dict, List, Optional
+
+
+def get_dict_section(
+    _dict: Dict[Any, Any], keys: Optional[List[Any]] = None
+) -> Dict[Any, Any]:
+    """Get section of a dictionary.
+
+    Args:
+        _dict (Dict[str, Any]): dictionary to access
+        keys (List[str]): list of keys to successively access in the dictionary
+
+    Returns:
+        Dict[str, Any]: section of dictionary requested
+    """
+    if keys is not None:
+        for key in keys:
+            _dict = _dict.get(key, {})
+
+    return _dict