feat: list argument callback (#129)

* feat: list argument callback

* fix: unused import

* fix: windows line ends

docs/known_issues.md

@@ -0,0 +1,55 @@
+# Known Issues
+
+This is a collection of known issues and workarounds to address them.
+
+## Argument list in config
+
+> Related GitHub issues: [typer-config#117](https://github.com/maxb2/typer-config/issues/117), [typer-config#124](https://github.com/maxb2/typer-config/issues/124).
+
+Providing values for a list argument in a config file doesn't work out of the box.
+You must use a custom callback for list arguments to extract the values from the config.
+Thanks to [@jlwhelan28](https://github.com/jlwhelan28) for the inital solution to this problem.
+Below is a working example of how to deal with an argument list:
+
+```{.python title="arg_list.py" test="true"}
+from typing import List
+import typer
+from typer_config import use_yaml_config
+from typer_config.callbacks import argument_list_callback
+
+app = typer.Typer()
+
+
+@app.command()
+@use_yaml_config()
+def main(
+    arg1: str,
+    arg2: List[str] = typer.Argument(default=None, callback=argument_list_callback),
+    opt1: str = typer.Option(...),
+    opt2: str = typer.Option("hello"),
+):
+    typer.echo(f"{opt1} {opt2} {arg1}")
+    typer.echo(f"{arg2}")
+
+
+if __name__ == "__main__":
+    app()
+```
+
+```yaml title="config.yml"
+# config.yml
+opt1: "apple"
+opt2: "pear"
+arg1: "lemon"
+arg2: ["oak", "aspen", "maple"]
+```
+
+```{.bash title="Terminal"}
+$ python arg_list.py --config config.yml
+apple pear lemon
+['oak', 'aspen', 'maple']
+
+$ python arg_list.py strawberry bear wolf snake tiger --config config.yml
+apple pear strawberry
+['bear', 'wolf', 'snake', 'tiger']
+```

mkdocs.yml

@@ -33,6 +33,7 @@ nav:
     - 'examples/schema.md'
     - 'examples/explicit_config.md'
     - 'examples/save_config.md'
+  - Known Issues: known_issues.md
   - API Reference: api.md
   - Changelog: changelog.md
 

tests/doc_examples.py

@@ -304,7 +304,12 @@ def exec_bash_fence(fence: Fence, **kwargs):
 
     for command in commands:
         result = run(command["input"], shell=True, check=True, capture_output=True)
-        assert result.stdout.decode().strip() == command["output"].strip()
+        assert (
+            result.stdout.decode()
+            .strip()
+            .replace("\r", "")  # NOTE: fixing windows line ends
+            == command["output"].strip()
+        )
 
 
 register_executor("bash", exec_bash_fence)

tests/test_docs.py

@@ -6,7 +6,11 @@
 from .doc_examples import check_typer_md_file
 
 
-@pytest.mark.parametrize("fpath", Path("docs/examples").glob("*.md"), ids=str)
+@pytest.mark.parametrize(
+    "fpath",
+    [*list(Path("docs/examples").glob("*.md")), Path("docs/known_issues.md")],
+    ids=str,
+)
 def test_doc_examples(fpath: Path):
     """Test doc file.
 

typer_config/callbacks.py

@@ -1,8 +1,18 @@
 """Typer Configuration Parameter Callbacks."""
 
+from __future__ import annotations
+
+from typing import List, Optional
+
 from typer import BadParameter, CallbackParam, Context
 
-from .__typing import ConfigLoader, ConfigParameterCallback, TyperParameterValue
+# NOTE: I'm not sure why, but these types must be imported at runtime
+# for the tests to pass...
+from .__typing import (  # noqa: TCH001
+    ConfigLoader,
+    ConfigParameterCallback,
+    TyperParameterValue,
+)
 from .loaders import (
     dotenv_loader,
     json_loader,
@@ -126,3 +136,25 @@ def _callback(
 Returns:
     TyperParameterValue: must return back the given parameter
 """
+
+
+def argument_list_callback(
+    ctx: Context, param: CallbackParam, param_value: Optional[List[str]]
+) -> List[str]:
+    """Argument list callback.
+
+    Note:
+        This is a shim to fix list arguments in a config.
+        See [maxb2/typer-config#124](https://github.com/maxb2/typer-config/issues/124).
+
+    Args:
+        ctx (typer.Context): typer context
+        param (typer.CallbackParam): typer parameter
+        param_value (Optional[List[str]]): typer parameter value
+
+    Returns:
+        List[str]: argument list
+    """
+    ctx.default_map = ctx.default_map or {}
+    default = ctx.default_map.get(param.name, []) if param.name else []
+    return param_value if param_value else default