Coverage for src/click/decorators.py: 14%
207 statements
« prev ^ index » next coverage.py v7.2.2, created at 2023-05-21 11:49 +0200
1import inspect
2import types
3import typing as t
4from functools import update_wrapper
5from gettext import gettext as _
7from .core import Argument
8from .core import Command
9from .core import Context
10from .core import Group
11from .core import Option
12from .core import Parameter
13from .globals import get_current_context
14from .utils import echo
16if t.TYPE_CHECKING: 16 ↛ 21line 16 didn't jump to line 21, because the condition on line 16 was never false
17 import typing_extensions as te
19 P = te.ParamSpec("P")
21R = t.TypeVar("R")
22T = t.TypeVar("T")
23_AnyCallable = t.Callable[..., t.Any]
24_Decorator: "te.TypeAlias" = t.Callable[[T], T]
25FC = t.TypeVar("FC", bound=t.Union[_AnyCallable, Command])
28def pass_context(f: "t.Callable[te.Concatenate[Context, P], R]") -> "t.Callable[P, R]":
29 """Marks a callback as wanting to receive the current context
30 object as first argument.
31 """
33 def new_func(*args: "P.args", **kwargs: "P.kwargs") -> "R":
34 return f(get_current_context(), *args, **kwargs)
36 return update_wrapper(new_func, f)
39def pass_obj(f: "t.Callable[te.Concatenate[t.Any, P], R]") -> "t.Callable[P, R]":
40 """Similar to :func:`pass_context`, but only pass the object on the
41 context onwards (:attr:`Context.obj`). This is useful if that object
42 represents the state of a nested system.
43 """
45 def new_func(*args: "P.args", **kwargs: "P.kwargs") -> "R":
46 return f(get_current_context().obj, *args, **kwargs)
48 return update_wrapper(new_func, f)
51def make_pass_decorator(
52 object_type: t.Type[T], ensure: bool = False
53) -> t.Callable[["t.Callable[te.Concatenate[T, P], R]"], "t.Callable[P, R]"]:
54 """Given an object type this creates a decorator that will work
55 similar to :func:`pass_obj` but instead of passing the object of the
56 current context, it will find the innermost context of type
57 :func:`object_type`.
59 This generates a decorator that works roughly like this::
61 from functools import update_wrapper
63 def decorator(f):
64 @pass_context
65 def new_func(ctx, *args, **kwargs):
66 obj = ctx.find_object(object_type)
67 return ctx.invoke(f, obj, *args, **kwargs)
68 return update_wrapper(new_func, f)
69 return decorator
71 :param object_type: the type of the object to pass.
72 :param ensure: if set to `True`, a new object will be created and
73 remembered on the context if it's not there yet.
74 """
76 def decorator(f: "t.Callable[te.Concatenate[T, P], R]") -> "t.Callable[P, R]":
77 def new_func(*args: "P.args", **kwargs: "P.kwargs") -> "R":
78 ctx = get_current_context()
80 obj: t.Optional[T]
81 if ensure:
82 obj = ctx.ensure_object(object_type)
83 else:
84 obj = ctx.find_object(object_type)
86 if obj is None:
87 raise RuntimeError(
88 "Managed to invoke callback without a context"
89 f" object of type {object_type.__name__!r}"
90 " existing."
91 )
93 return ctx.invoke(f, obj, *args, **kwargs)
95 return update_wrapper(new_func, f)
97 return decorator
100def pass_meta_key(
101 key: str, *, doc_description: t.Optional[str] = None
102) -> "t.Callable[[t.Callable[te.Concatenate[t.Any, P], R]], t.Callable[P, R]]":
103 """Create a decorator that passes a key from
104 :attr:`click.Context.meta` as the first argument to the decorated
105 function.
107 :param key: Key in ``Context.meta`` to pass.
108 :param doc_description: Description of the object being passed,
109 inserted into the decorator's docstring. Defaults to "the 'key'
110 key from Context.meta".
112 .. versionadded:: 8.0
113 """
115 def decorator(f: "t.Callable[te.Concatenate[t.Any, P], R]") -> "t.Callable[P, R]":
116 def new_func(*args: "P.args", **kwargs: "P.kwargs") -> R:
117 ctx = get_current_context()
118 obj = ctx.meta[key]
119 return ctx.invoke(f, obj, *args, **kwargs)
121 return update_wrapper(new_func, f)
123 if doc_description is None:
124 doc_description = f"the {key!r} key from :attr:`click.Context.meta`"
126 decorator.__doc__ = (
127 f"Decorator that passes {doc_description} as the first argument"
128 " to the decorated function."
129 )
130 return decorator
133CmdType = t.TypeVar("CmdType", bound=Command)
136# variant: no call, directly as decorator for a function.
137@t.overload
138def command(name: _AnyCallable) -> Command:
139 ...
142# variant: with positional name and with positional or keyword cls argument:
143# @command(namearg, CommandCls, ...) or @command(namearg, cls=CommandCls, ...)
144@t.overload
145def command(
146 name: t.Optional[str],
147 cls: t.Type[CmdType],
148 **attrs: t.Any,
149) -> t.Callable[[_AnyCallable], CmdType]:
150 ...
153# variant: name omitted, cls _must_ be a keyword argument, @command(cmd=CommandCls, ...)
154# The correct way to spell this overload is to use keyword-only argument syntax:
155# def command(*, cls: t.Type[CmdType], **attrs: t.Any) -> ...
156# However, mypy thinks this doesn't fit the overloaded function. Pyright does
157# accept that spelling, and the following work-around makes pyright issue a
158# warning that CmdType could be left unsolved, but mypy sees it as fine. *shrug*
159@t.overload
160def command(
161 name: None = None,
162 cls: t.Type[CmdType] = ...,
163 **attrs: t.Any,
164) -> t.Callable[[_AnyCallable], CmdType]:
165 ...
168# variant: with optional string name, no cls argument provided.
169@t.overload
170def command(
171 name: t.Optional[str] = ..., cls: None = None, **attrs: t.Any
172) -> t.Callable[[_AnyCallable], Command]:
173 ...
176def command(
177 name: t.Union[t.Optional[str], _AnyCallable] = None,
178 cls: t.Optional[t.Type[CmdType]] = None,
179 **attrs: t.Any,
180) -> t.Union[Command, t.Callable[[_AnyCallable], t.Union[Command, CmdType]]]:
181 r"""Creates a new :class:`Command` and uses the decorated function as
182 callback. This will also automatically attach all decorated
183 :func:`option`\s and :func:`argument`\s as parameters to the command.
185 The name of the command defaults to the name of the function with
186 underscores replaced by dashes. If you want to change that, you can
187 pass the intended name as the first argument.
189 All keyword arguments are forwarded to the underlying command class.
190 For the ``params`` argument, any decorated params are appended to
191 the end of the list.
193 Once decorated the function turns into a :class:`Command` instance
194 that can be invoked as a command line utility or be attached to a
195 command :class:`Group`.
197 :param name: the name of the command. This defaults to the function
198 name with underscores replaced by dashes.
199 :param cls: the command class to instantiate. This defaults to
200 :class:`Command`.
202 .. versionchanged:: 8.1
203 This decorator can be applied without parentheses.
205 .. versionchanged:: 8.1
206 The ``params`` argument can be used. Decorated params are
207 appended to the end of the list.
208 """
210 func: t.Optional[t.Callable[[_AnyCallable], t.Any]] = None
212 if callable(name):
213 func = name
214 name = None
215 assert cls is None, "Use 'command(cls=cls)(callable)' to specify a class."
216 assert not attrs, "Use 'command(**kwargs)(callable)' to provide arguments."
218 if cls is None:
219 cls = t.cast(t.Type[CmdType], Command)
221 def decorator(f: _AnyCallable) -> CmdType:
222 if isinstance(f, Command):
223 raise TypeError("Attempted to convert a callback into a command twice.")
225 attr_params = attrs.pop("params", None)
226 params = attr_params if attr_params is not None else []
228 try:
229 decorator_params = f.__click_params__ # type: ignore
230 except AttributeError:
231 pass
232 else:
233 del f.__click_params__ # type: ignore
234 params.extend(reversed(decorator_params))
236 if attrs.get("help") is None: 236 ↛ 237, 236 ↛ 2392 missed branches: 1) line 236 didn't jump to line 237, because the condition on line 236 was never true, 2) line 236 didn't jump to line 239, because the condition on line 236 was never false
237 attrs["help"] = f.__doc__
239 if t.TYPE_CHECKING: 239 ↛ 243line 239 didn't jump to line 243, because the condition on line 239 was never false
240 assert cls is not None
241 assert not callable(name)
243 cmd = cls(
244 name=name or f.__name__.lower().replace("_", "-"),
245 callback=f,
246 params=params,
247 **attrs,
248 )
249 cmd.__doc__ = f.__doc__
250 return cmd
252 if func is not None:
253 return decorator(func)
255 return decorator
258GrpType = t.TypeVar("GrpType", bound=Group)
261# variant: no call, directly as decorator for a function.
262@t.overload
263def group(name: _AnyCallable) -> Group:
264 ...
267# variant: with positional name and with positional or keyword cls argument:
268# @group(namearg, GroupCls, ...) or @group(namearg, cls=GroupCls, ...)
269@t.overload
270def group(
271 name: t.Optional[str],
272 cls: t.Type[GrpType],
273 **attrs: t.Any,
274) -> t.Callable[[_AnyCallable], GrpType]:
275 ...
278# variant: name omitted, cls _must_ be a keyword argument, @group(cmd=GroupCls, ...)
279# The _correct_ way to spell this overload is to use keyword-only argument syntax:
280# def group(*, cls: t.Type[GrpType], **attrs: t.Any) -> ...
281# However, mypy thinks this doesn't fit the overloaded function. Pyright does
282# accept that spelling, and the following work-around makes pyright issue a
283# warning that GrpType could be left unsolved, but mypy sees it as fine. *shrug*
284@t.overload
285def group(
286 name: None = None,
287 cls: t.Type[GrpType] = ...,
288 **attrs: t.Any,
289) -> t.Callable[[_AnyCallable], GrpType]:
290 ...
293# variant: with optional string name, no cls argument provided.
294@t.overload
295def group(
296 name: t.Optional[str] = ..., cls: None = None, **attrs: t.Any
297) -> t.Callable[[_AnyCallable], Group]:
298 ...
301def group(
302 name: t.Union[str, _AnyCallable, None] = None,
303 cls: t.Optional[t.Type[GrpType]] = None,
304 **attrs: t.Any,
305) -> t.Union[Group, t.Callable[[_AnyCallable], t.Union[Group, GrpType]]]:
306 """Creates a new :class:`Group` with a function as callback. This
307 works otherwise the same as :func:`command` just that the `cls`
308 parameter is set to :class:`Group`.
310 .. versionchanged:: 8.1
311 This decorator can be applied without parentheses.
312 """
313 if cls is None:
314 cls = t.cast(t.Type[GrpType], Group)
316 if callable(name):
317 return command(cls=cls, **attrs)(name)
319 return command(name, cls, **attrs)
322def _param_memo(f: t.Callable[..., t.Any], param: Parameter) -> None:
323 if isinstance(f, Command):
324 f.params.append(param)
325 else:
326 if not hasattr(f, "__click_params__"):
327 f.__click_params__ = [] # type: ignore
329 f.__click_params__.append(param) # type: ignore
332def argument(*param_decls: str, **attrs: t.Any) -> _Decorator[FC]:
333 """Attaches an argument to the command. All positional arguments are
334 passed as parameter declarations to :class:`Argument`; all keyword
335 arguments are forwarded unchanged (except ``cls``).
336 This is equivalent to creating an :class:`Argument` instance manually
337 and attaching it to the :attr:`Command.params` list.
339 :param cls: the argument class to instantiate. This defaults to
340 :class:`Argument`.
341 """
343 def decorator(f: FC) -> FC:
344 ArgumentClass = attrs.pop("cls", None) or Argument
345 _param_memo(f, ArgumentClass(param_decls, **attrs))
346 return f
348 return decorator
351def option(*param_decls: str, **attrs: t.Any) -> _Decorator[FC]:
352 """Attaches an option to the command. All positional arguments are
353 passed as parameter declarations to :class:`Option`; all keyword
354 arguments are forwarded unchanged (except ``cls``).
355 This is equivalent to creating an :class:`Option` instance manually
356 and attaching it to the :attr:`Command.params` list.
358 :param cls: the option class to instantiate. This defaults to
359 :class:`Option`.
360 """
362 def decorator(f: FC) -> FC:
363 # Issue 926, copy attrs, so pre-defined options can re-use the same cls=
364 option_attrs = attrs.copy()
365 OptionClass = option_attrs.pop("cls", None) or Option
366 _param_memo(f, OptionClass(param_decls, **option_attrs))
367 return f
369 return decorator
372def confirmation_option(*param_decls: str, **kwargs: t.Any) -> _Decorator[FC]:
373 """Add a ``--yes`` option which shows a prompt before continuing if
374 not passed. If the prompt is declined, the program will exit.
376 :param param_decls: One or more option names. Defaults to the single
377 value ``"--yes"``.
378 :param kwargs: Extra arguments are passed to :func:`option`.
379 """
381 def callback(ctx: Context, param: Parameter, value: bool) -> None:
382 if not value:
383 ctx.abort()
385 if not param_decls:
386 param_decls = ("--yes",)
388 kwargs.setdefault("is_flag", True)
389 kwargs.setdefault("callback", callback)
390 kwargs.setdefault("expose_value", False)
391 kwargs.setdefault("prompt", "Do you want to continue?")
392 kwargs.setdefault("help", "Confirm the action without prompting.")
393 return option(*param_decls, **kwargs)
396def password_option(*param_decls: str, **kwargs: t.Any) -> _Decorator[FC]:
397 """Add a ``--password`` option which prompts for a password, hiding
398 input and asking to enter the value again for confirmation.
400 :param param_decls: One or more option names. Defaults to the single
401 value ``"--password"``.
402 :param kwargs: Extra arguments are passed to :func:`option`.
403 """
404 if not param_decls:
405 param_decls = ("--password",)
407 kwargs.setdefault("prompt", True)
408 kwargs.setdefault("confirmation_prompt", True)
409 kwargs.setdefault("hide_input", True)
410 return option(*param_decls, **kwargs)
413def version_option(
414 version: t.Optional[str] = None,
415 *param_decls: str,
416 package_name: t.Optional[str] = None,
417 prog_name: t.Optional[str] = None,
418 message: t.Optional[str] = None,
419 **kwargs: t.Any,
420) -> _Decorator[FC]:
421 """Add a ``--version`` option which immediately prints the version
422 number and exits the program.
424 If ``version`` is not provided, Click will try to detect it using
425 :func:`importlib.metadata.version` to get the version for the
426 ``package_name``. On Python < 3.8, the ``importlib_metadata``
427 backport must be installed.
429 If ``package_name`` is not provided, Click will try to detect it by
430 inspecting the stack frames. This will be used to detect the
431 version, so it must match the name of the installed package.
433 :param version: The version number to show. If not provided, Click
434 will try to detect it.
435 :param param_decls: One or more option names. Defaults to the single
436 value ``"--version"``.
437 :param package_name: The package name to detect the version from. If
438 not provided, Click will try to detect it.
439 :param prog_name: The name of the CLI to show in the message. If not
440 provided, it will be detected from the command.
441 :param message: The message to show. The values ``%(prog)s``,
442 ``%(package)s``, and ``%(version)s`` are available. Defaults to
443 ``"%(prog)s, version %(version)s"``.
444 :param kwargs: Extra arguments are passed to :func:`option`.
445 :raise RuntimeError: ``version`` could not be detected.
447 .. versionchanged:: 8.0
448 Add the ``package_name`` parameter, and the ``%(package)s``
449 value for messages.
451 .. versionchanged:: 8.0
452 Use :mod:`importlib.metadata` instead of ``pkg_resources``. The
453 version is detected based on the package name, not the entry
454 point name. The Python package name must match the installed
455 package name, or be passed with ``package_name=``.
456 """
457 if message is None:
458 message = _("%(prog)s, version %(version)s")
460 if version is None and package_name is None:
461 frame = inspect.currentframe()
462 f_back = frame.f_back if frame is not None else None
463 f_globals = f_back.f_globals if f_back is not None else None
464 # break reference cycle
465 # https://docs.python.org/3/library/inspect.html#the-interpreter-stack
466 del frame
468 if f_globals is not None:
469 package_name = f_globals.get("__name__")
471 if package_name == "__main__":
472 package_name = f_globals.get("__package__")
474 if package_name:
475 package_name = package_name.partition(".")[0]
477 def callback(ctx: Context, param: Parameter, value: bool) -> None:
478 if not value or ctx.resilient_parsing:
479 return
481 nonlocal prog_name
482 nonlocal version
484 if prog_name is None:
485 prog_name = ctx.find_root().info_name
487 if version is None and package_name is not None:
488 metadata: t.Optional[types.ModuleType]
490 try:
491 from importlib import metadata # type: ignore
492 except ImportError:
493 # Python < 3.8
494 import importlib_metadata as metadata # type: ignore
496 try:
497 version = metadata.version(package_name) # type: ignore
498 except metadata.PackageNotFoundError: # type: ignore
499 raise RuntimeError(
500 f"{package_name!r} is not installed. Try passing"
501 " 'package_name' instead."
502 ) from None
504 if version is None:
505 raise RuntimeError(
506 f"Could not determine the version for {package_name!r} automatically."
507 )
509 echo(
510 t.cast(str, message)
511 % {"prog": prog_name, "package": package_name, "version": version},
512 color=ctx.color,
513 )
514 ctx.exit()
516 if not param_decls:
517 param_decls = ("--version",)
519 kwargs.setdefault("is_flag", True)
520 kwargs.setdefault("expose_value", False)
521 kwargs.setdefault("is_eager", True)
522 kwargs.setdefault("help", _("Show the version and exit."))
523 kwargs["callback"] = callback
524 return option(*param_decls, **kwargs)
527def help_option(*param_decls: str, **kwargs: t.Any) -> _Decorator[FC]:
528 """Add a ``--help`` option which immediately prints the help page
529 and exits the program.
531 This is usually unnecessary, as the ``--help`` option is added to
532 each command automatically unless ``add_help_option=False`` is
533 passed.
535 :param param_decls: One or more option names. Defaults to the single
536 value ``"--help"``.
537 :param kwargs: Extra arguments are passed to :func:`option`.
538 """
540 def callback(ctx: Context, param: Parameter, value: bool) -> None:
541 if not value or ctx.resilient_parsing:
542 return
544 echo(ctx.get_help(), color=ctx.color)
545 ctx.exit()
547 if not param_decls:
548 param_decls = ("--help",)
550 kwargs.setdefault("is_flag", True)
551 kwargs.setdefault("expose_value", False)
552 kwargs.setdefault("is_eager", True)
553 kwargs.setdefault("help", _("Show this message and exit."))
554 kwargs["callback"] = callback
555 return option(*param_decls, **kwargs)