55 lines
2.4 KiB
Python
55 lines
2.4 KiB
Python
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import inspect
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from collections.abc import Callable
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from typing import Any, TypeVar, get_type_hints
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T = TypeVar("T")
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R = TypeVar("R")
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def create_call_wrapper(func: Callable[..., R], request_type: type[T]) -> Callable[[T], R]:
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"""
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Create a wrapper function that knows how to call func with the request object.
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Returns a wrapper function that takes the request and calls func appropriately.
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The wrapper handles three calling patterns:
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1. Positional-only parameter typed as request_type (no default): func(req)
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2. Positional/keyword parameter typed as request_type (no default): func(**{param_name: req})
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3. No request parameter or parameter with default: func()
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"""
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try:
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sig = inspect.signature(func)
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type_hints = get_type_hints(func)
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except (ValueError, TypeError, NameError): # pragma: no cover
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return lambda _: func()
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# Check for positional-only parameter typed as request_type
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for param_name, param in sig.parameters.items():
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if param.kind == inspect.Parameter.POSITIONAL_ONLY:
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param_type = type_hints.get(param_name)
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if param_type == request_type: # pragma: no branch
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# Check if it has a default - if so, treat as old style
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if param.default is not inspect.Parameter.empty: # pragma: no cover
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return lambda _: func()
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# Found positional-only parameter with correct type and no default
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return lambda req: func(req)
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# Check for any positional/keyword parameter typed as request_type
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for param_name, param in sig.parameters.items():
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if param.kind in (inspect.Parameter.POSITIONAL_OR_KEYWORD, inspect.Parameter.KEYWORD_ONLY): # pragma: no branch
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param_type = type_hints.get(param_name)
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if param_type == request_type:
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# Check if it has a default - if so, treat as old style
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if param.default is not inspect.Parameter.empty: # pragma: no cover
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return lambda _: func()
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# Found keyword parameter with correct type and no default
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# Need to capture param_name in closure properly
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def make_keyword_wrapper(name: str) -> Callable[[Any], Any]:
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return lambda req: func(**{name: req})
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return make_keyword_wrapper(param_name)
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# No request parameter found - use old style
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return lambda _: func()
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