mypy error in the logger.configure(**config) example from the documentation

[DeadNews]

Looks like mypy issue.
But I'll leave it here just in case.

---

loguru/README.rst

Lines 368 to 376 in 493fb2d

	# For scripts
	config = {
	"handlers": [
	{"sink": sys.stdout, "format": "{time} - {message}"},
	{"sink": "file.log", "serialize": True},
	],
	"extra": {"user": "someone"}
	}
	logger.configure(**config)

or

loguru/tests/test_configure.py

Lines 69 to 78 in 493fb2d

	def test_dict_unpacking(writer):
	config = {
	"handlers": [{"sink": writer, "format": "{level.no} - {extra[x]} {extra[z]} - {message}"}],
	"levels": [{"name": "test", "no": 30}],
	"extra": {"x": 1, "y": 2, "z": 3},
	}
	logger.debug("NOPE")
	logger.configure(**config)

Causing the following mypy error:

test.py:15:20: error: Argument 1 to "configure" of "Logger" has incompatible type "**dict[str, Collection[object]]"; expected "Sequence[dict[str, Any]]"  [arg-type]
test.py:15:20: error: Argument 1 to "configure" of "Logger" has incompatible type "**dict[str, Collection[object]]"; expected "Sequence[LevelConfig] | None"  [arg-type]
test.py:15:20: error: Argument 1 to "configure" of "Logger" has incompatible type "**dict[str, Collection[object]]"; expected "dict[Any, Any] | None"  [arg-type]
test.py:15:20: error: Argument 1 to "configure" of "Logger" has incompatible type "**dict[str, Collection[object]]"; expected "Callable[[Record], None] | None"  [arg-type]
test.py:15:20: error: Argument 1 to "configure" of "Logger" has incompatible type "**dict[str, Collection[object]]"; expected "Sequence[tuple[str | None, bool]] | None"  [arg-type]

This code does not cause any mypy errors:

import sys
from typing import Any

from loguru import logger

# For scripts
config: dict[str, Any] = {
    "handlers": [
        {"sink": sys.stdout, "format": "{time} - {message}"},
        {"sink": "file.log", "serialize": True},
    ],
    "extra": {"user": "someone"},
}
logger.configure(**config)

or

import sys
from collections.abc import Sequence
from typing import Any, TypedDict

from loguru import logger


class Config(TypedDict):
    """Loguru config."""

    handlers: Sequence[dict[str, Any]]
    extra: dict[Any, Any] | None


# For scripts
config: Config = {
    "handlers": [
        {"sink": sys.stdout, "format": "{time} - {message}"},
        {"sink": "file.log", "serialize": True},
    ],
    "extra": {"user": "someone"},
}
logger.configure(**config)

ref: python/mypy#14073, python/mypy#5382

[Delgan]

Thanks for the report and the Mypy references.

From what I understand there's not much we can do on the Loguru side unfortunately.

We could add a ConfigDict type publicly available. However, that doesn't solve the underlying problem. By default, an error will still be raised if the user does not explicitly add type-annotation to the config dictionary. Most importantly, this would only apply to configure(). If the user decides to use dict unpacking to call let's say logger.add(), they will face the same issue.
This implies that each method would need to define an associated TypedDict in case the user wanted to use dict unpacking, which becomes very cumbersome and not desirable.

We could also add a @overload to logger.configure() type hints but that means that some invalid configurations will no longer be detected.

It looks like Mypy should extract Literal from these dict when possible, and map them to the method signature (which is not trivial as Mypy can't guess the dict is immutable and not generic). At least, the config type should be infered as dict[str, Any] instead of current dict[str, Collection[object]]. Pyright seems to handle that correctly.