feat: ini decorator (#102)

* chore(docs): remove deprecated example from `ini_loader` docstring

* feat: ini decorator

* chore: include ini in default value tests

docs/examples/default_config.md

@@ -26,7 +26,9 @@ if __name__ == "__main__":
     app()
 ```
 
-1. This package also provides `use_json_config`, `use_toml_config`, and `use_dotenv_config` for those file formats.
+1. This package also provides `use_json_config`, `use_toml_config`, `use_ini_config`, and `use_dotenv_config` for those file formats.
+   > Note that since INI requires a top-level section `use_ini_config` requires a list of strings that express the path to the section
+   you wish to use, e.g. `@use_ini_config(["section", "subsection", ...])`. 
 
 With a config file:
 

docs/index.md

@@ -39,8 +39,10 @@ if __name__ == "__main__":
     app()
 ```
 
-1. This package also provides `@use_json_config`, `@use_toml_config`, and `@use_dotenv_config` for those file formats.
+1. This package also provides `use_json_config`, `use_toml_config`, `use_ini_config`, and `use_dotenv_config` for those file formats.
    You can also use your own loader function and the `@use_config(loader_func)` decorator.
+   > Note that since INI requires a top-level section `use_ini_config` requires a list of strings that express the path to the section
+   you wish to use, e.g. `@use_ini_config(["section", "subsection", ...])`. 
 
 2. The `app.command()` decorator registers the function object in a lookup table, so we must transform our command before registration.
 

tests/test_example.py

@@ -92,7 +92,9 @@ def main(
     (
         str(HERE.joinpath("config.ini")),
         INI_CALLBACK,
-        functools.partial(typer_config.decorators.use_config, callback=INI_CALLBACK),
+        functools.partial(
+            typer_config.decorators.use_ini_config, section=["simple_app"]
+        ),
     ),
 ]
 
@@ -173,10 +175,6 @@ def test_simple_example_decorated_default(simple_app_decorated, confs):
 
     conf, _, dec = confs
 
-    # skip ini config
-    if conf.endswith(".ini"):
-        return
-
     _app = simple_app_decorated(dec, default_value=conf)
 
     result = RUNNER.invoke(_app, ["--help"])

typer_config/decorators.py

@@ -5,7 +5,7 @@
 from enum import Enum
 from functools import wraps
 from inspect import Parameter, signature
-from typing import TYPE_CHECKING, Optional
+from typing import TYPE_CHECKING, List, Optional
 
 from typer import Option
 
@@ -19,6 +19,7 @@
 from .dumpers import json_dumper, toml_dumper, yaml_dumper
 from .loaders import (
     dotenv_loader,
+    ini_loader,
     json_loader,
     loader_transformer,
     toml_loader,
@@ -27,6 +28,7 @@
 
 if TYPE_CHECKING:  # pragma: no cover
     from .__typing import (
+        ConfigDict,
         ConfigDumper,
         ConfigParameterCallback,
         FilePath,
@@ -292,6 +294,68 @@ def main(...):
     return use_config(callback=callback, param_name=param_name, param_help=param_help)
 
 
+def use_ini_config(
+    section: List[str],
+    param_name: TyperParameterName = "config",
+    param_help: str = "Configuration file.",
+    default_value: Optional[TyperParameterValue] = None,
+) -> TyperCommandDecorator:
+    """Decorator for using INI configuration on a typer command.
+
+    Usage:
+        ```py
+        import typer
+        from typer_config.decorators import use_ini_config
+
+        app = typer.Typer()
+
+        @app.command()
+        @use_ini_config(["section", "subsection"])
+        def main(...):
+            ...
+        ```
+
+    Args:
+        section (List[str]): List of nested sections to access in the INI file.
+        param_name (str, optional): name of config parameter. Defaults to "config".
+        param_help (str, optional): config parameter help string.
+            Defaults to "Configuration file.".
+        default_value (TyperParameterValue, optional): default config parameter value.
+            Defaults to None.
+
+    Returns:
+        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),
+            )
+        )
+
+    return use_config(callback=callback, param_name=param_name, param_help=param_help)
+
+
 def dump_config(dumper: ConfigDumper, location: FilePath) -> TyperCommandDecorator:
     """Decorator for dumping a config file with parameters
     from an invocation of a typer command.

typer_config/loaders.py

@@ -196,10 +196,14 @@ def ini_loader(param_value: TyperParameterValue) -> ConfigDict:
 
     Note:
         INI files must have sections at the top level.
-        You probably want to combine this with `subpath_loader`.
+        You probably want to combine this with `loader_transformer`
+        to extract the correct section.
         For example:
         ```py
-        ini_section_loader = subpath_loader(ini_loader, ["section"])
+        ini_section_loader = loader_transformer(
+            ini_loader,
+            config_transformer=lambda config: config["section"],
+        )
         ```
 
     Args: