Coverage for src/configuraptor/core.py: 100%
221 statements
« prev ^ index » next coverage.py v7.2.7, created at 2025-01-09 20:20 +0100
« prev ^ index » next coverage.py v7.2.7, created at 2025-01-09 20:20 +0100
1"""
2Contains most of the loading logic.
3"""
5import dataclasses as dc
6import io
7import os
8import typing
9import warnings
10from pathlib import Path
11from typing import Any, Type
13import requests
15from . import loaders
16from .abs import AnyType, C, T, T_data, Type_C
17from .alias import Alias, has_alias
18from .binary_config import BinaryConfig
19from .errors import (
20 ConfigErrorCouldNotConvert,
21 ConfigErrorInvalidType,
22 ConfigErrorMissingKey,
23)
24from .helpers import (
25 all_annotations,
26 camel_to_snake,
27 check_type,
28 dataclass_field,
29 find_pyproject_toml,
30 is_custom_class,
31 is_optional,
32 is_parameterized,
33)
34from .postpone import Postponed
35from .type_converters import CONVERTERS
38def _data_for_nested_key(key: str, raw: dict[str, typing.Any]) -> dict[str, typing.Any]:
39 """
40 If a key contains a dot, traverse the raw dict until the right key was found.
42 Example:
43 key = some.nested.key
44 raw = {"some": {"nested": {"key": {"with": "data"}}}}
45 -> {"with": "data"}
46 """
47 parts = key.split(".")
48 while parts:
49 key = parts.pop(0)
50 if key not in raw:
51 return {}
53 raw = raw[key]
55 return raw
58def _guess_key(clsname: str) -> str:
59 """
60 If no key is manually defined for `load_into`, \
61 the class' name is converted to snake_case to use as the default key.
62 """
63 return camel_to_snake(clsname)
66def _from_mock_url(url: str) -> str:
67 """
68 Pytest only: when starting a url with mock:// it is expected to just be json afterwards.
69 """
70 return url.removeprefix("mock://")
73def guess_filetype_for_url(url: str, response: requests.Response = None) -> str:
74 """
75 Based on the url (which may have an extension) and the requests response \
76 (which may have a content-type), try to guess the right filetype (-> loader, e.g. json or yaml).
78 Falls back to JSON if none can be found.
79 """
80 url = url.split("?")[0]
81 if url_extension := os.path.splitext(url)[1].lower():
82 return url_extension.strip(".")
84 if response and (content_type_header := response.headers.get("content-type", "").split(";")[0].strip()):
85 content_type = content_type_header.split("/")[-1]
86 if content_type != "plain":
87 return content_type
89 # If both methods fail, default to JSON
90 return "json"
93def from_url(url: str, _dummy: bool = False) -> tuple[io.BytesIO, str]:
94 """
95 Load data as bytes into a file-like object and return the file type.
97 This can be used by __load_data:
98 > loader = loaders.get(filetype)
99 > # dev/null exists but always returns b''
100 > data = loader(contents, Path("/dev/null"))
101 """
102 if url.startswith("mock://"):
103 data = _from_mock_url(url)
104 resp = None
105 elif _dummy:
106 resp = None
107 data = "{}"
108 else:
109 resp = requests.get(url, timeout=10)
110 data = resp.text
112 filetype = guess_filetype_for_url(url, resp)
113 return io.BytesIO(data.encode()), filetype
116def _load_data(
117 data: T_data,
118 key: str = None,
119 classname: str = None,
120 lower_keys: bool = False,
121 allow_types: tuple[type, ...] = (dict,),
122) -> dict[str, typing.Any]:
123 """
124 Tries to load the right data from a filename/path or dict, based on a manual key or a classname.
126 E.g. class Tool will be mapped to key tool.
127 It also deals with nested keys (tool.extra -> {"tool": {"extra": ...}}
128 """
129 if isinstance(data, bytes):
130 # instantly return, don't modify
131 # bytes as inputs -> bytes as output
132 # but since `T_data` is re-used, that's kind of hard to type for mypy.
133 return data # type: ignore
135 if isinstance(data, list):
136 if not data:
137 raise ValueError("Empty list passed!")
139 final_data: dict[str, typing.Any] = {}
140 for source in data:
141 final_data |= load_data(source, key=key, classname=classname, lower_keys=True, allow_types=allow_types)
143 return final_data
145 if isinstance(data, str):
146 if data.startswith(("http://", "https://", "mock://")):
147 contents, filetype = from_url(data)
149 loader = loaders.get(filetype)
150 # dev/null exists but always returns b''
151 data = loader(contents, Path("/dev/null"))
152 else:
153 data = Path(data)
155 if isinstance(data, Path):
156 with data.open("rb") as f:
157 loader = loaders.get(data.suffix or data.name)
158 data = loader(f, data.resolve())
160 if not data:
161 return {}
163 if key is None:
164 # try to guess key by grabbing the first one or using the class name
165 if len(data) == 1:
166 key = next(iter(data.keys()))
167 elif classname is not None:
168 key = _guess_key(classname)
170 if key:
171 data = _data_for_nested_key(key, data)
173 if not data:
174 raise ValueError("No data found!")
176 if not isinstance(data, allow_types):
177 raise ValueError(f"Data should be one of {allow_types} but it is {type(data)}!")
179 if lower_keys and isinstance(data, dict):
180 data = {k.lower(): v for k, v in data.items()}
182 return typing.cast(dict[str, typing.Any], data)
185def load_data(
186 data: T_data,
187 key: str = None,
188 classname: str = None,
189 lower_keys: bool = False,
190 allow_types: tuple[type, ...] = (dict,),
191) -> dict[str, typing.Any]:
192 """
193 Wrapper around __load_data that retries with key="" if anything goes wrong.
194 """
195 if data is None:
196 # try to load pyproject.toml
197 data = find_pyproject_toml()
199 try:
200 return _load_data(data, key, classname, lower_keys=lower_keys, allow_types=allow_types)
201 except Exception as e:
202 # sourcery skip: remove-unnecessary-else, simplify-empty-collection-comparison, swap-if-else-branches
203 # @sourcery: `key != ""` is NOT the same as `not key`
204 if key != "":
205 return _load_data(data, "", classname, lower_keys=lower_keys, allow_types=allow_types)
206 else: # pragma: no cover
207 warnings.warn(f"Data could not be loaded: {e}", source=e)
208 # key already was "", just return data!
209 # (will probably not happen but fallback)
210 return {}
213F = typing.TypeVar("F")
216def convert_between(from_value: F, from_type: Type[F], to_type: Type[T]) -> T:
217 """
218 Convert a value between types.
219 """
220 if converter := CONVERTERS.get((from_type, to_type)):
221 return typing.cast(T, converter(from_value))
223 # default: just convert type:
224 return to_type(from_value) # type: ignore
227def check_and_convert_type(value: Any, _type: Type[T], convert_types: bool, key: str = "variable") -> T:
228 """
229 Checks if the given value matches the specified type. If it does, the value is returned as is.
231 Args:
232 value (Any): The value to be checked and potentially converted.
233 _type (Type[T]): The expected type for the value.
234 convert_types (bool): If True, allows type conversion if the types do not match.
235 key (str, optional): The name or key associated with the variable (used in error messages).
236 Defaults to "variable".
238 Returns:
239 T: The value, potentially converted to the expected type.
241 Raises:
242 ConfigErrorInvalidType: If the type does not match, and type conversion is not allowed.
243 ConfigErrorCouldNotConvert: If type conversion fails.
244 """
245 if check_type(value, _type):
246 # type matches
247 return value
249 if isinstance(value, Alias):
250 if is_optional(_type):
251 return typing.cast(T, None)
252 else:
253 # unresolved alias, error should've already been thrown for parent but lets do it again:
254 raise ConfigErrorInvalidType(value.to, value=value, expected_type=_type)
256 if not convert_types:
257 # type does not match and should not be converted
258 raise ConfigErrorInvalidType(key, value=value, expected_type=_type)
260 # else: type does not match, try to convert it
261 try:
262 return convert_between(value, type(value), _type)
263 except (TypeError, ValueError) as e:
264 raise ConfigErrorCouldNotConvert(type(value), _type, value) from e
267def ensure_types(
268 data: dict[str, T], annotations: dict[str, type[T]], convert_types: bool = False
269) -> dict[str, T | None]:
270 """
271 Make sure all values in 'data' are in line with the ones stored in 'annotations'.
273 If an annotated key in missing from data, it will be filled with None for convenience.
275 TODO: python 3.11 exception groups to throw multiple errors at once!
276 """
277 # custom object to use instead of None, since typing.Optional can be None!
278 # cast to T to make mypy happy
279 notfound = typing.cast(T, object())
281 final: dict[str, T | None] = {}
282 for key, _type in annotations.items():
283 compare = data.get(key, notfound)
284 if compare is notfound: # pragma: nocover
285 warnings.warn("This should not happen since `load_recursive` already fills `data` based on `annotations`")
286 # skip!
287 continue
289 if isinstance(compare, Postponed):
290 # don't do anything with this item!
291 continue
293 if isinstance(compare, Alias):
294 related_data = data.get(compare.to, notfound)
295 if related_data is not notfound:
296 if isinstance(related_data, Postponed):
297 # also continue alias for postponed items
298 continue
300 # original key set, update alias
301 compare = related_data
303 compare = check_and_convert_type(compare, _type, convert_types, key)
305 final[key] = compare
307 return final
310def convert_key(key: str) -> str:
311 """
312 Replaces '-' and '.' in keys with '_' so it can be mapped to the Config properties.
313 """
314 return key.replace("-", "_").replace(".", "_")
317def convert_config(items: dict[str, T]) -> dict[str, T]:
318 """
319 Converts the config dict (from toml) or 'overwrites' dict in two ways.
321 1. removes any items where the value is None, since in that case the default should be used;
322 2. replaces '-' and '.' in keys with '_' so it can be mapped to the Config properties.
323 """
324 return {convert_key(k): v for k, v in items.items() if v is not None}
327def load_recursive(
328 cls: AnyType, data: dict[str, T], annotations: dict[str, AnyType], convert_types: bool = False
329) -> dict[str, T]:
330 """
331 For all annotations (recursively gathered from parents with `all_annotations`), \
332 try to resolve the tree of annotations.
334 Uses `load_into_recurse`, not itself directly.
336 Example:
337 class First:
338 key: str
340 class Second:
341 other: First
343 # step 1
344 cls = Second
345 data = {"second": {"other": {"key": "anything"}}}
346 annotations: {"other": First}
348 # step 1.5
349 data = {"other": {"key": "anything"}
350 annotations: {"other": First}
352 # step 2
353 cls = First
354 data = {"key": "anything"}
355 annotations: {"key": str}
358 TODO: python 3.11 exception groups to throw multiple errors at once!
359 """
360 updated = {}
362 for _key, _type in annotations.items():
363 if _key in data:
364 value: typing.Any = data[_key] # value can change so define it as any instead of T
365 if is_parameterized(_type):
366 origin = typing.get_origin(_type)
367 arguments = typing.get_args(_type)
368 if origin is list and arguments and is_custom_class(arguments[0]):
369 subtype = arguments[0]
370 value = [_load_into_recurse(subtype, subvalue, convert_types=convert_types) for subvalue in value]
372 elif origin is dict and arguments and is_custom_class(arguments[1]):
373 # e.g. dict[str, Point]
374 subkeytype, subvaluetype = arguments
375 # subkey(type) is not a custom class, so don't try to convert it:
376 value = {
377 subkey: _load_into_recurse(subvaluetype, subvalue, convert_types=convert_types)
378 for subkey, subvalue in value.items()
379 }
380 # elif origin is dict:
381 # keep data the same
382 elif origin is typing.Union and arguments:
383 for arg in arguments:
384 if is_custom_class(arg):
385 value = _load_into_recurse(arg, value, convert_types=convert_types)
387 # todo: other parameterized/unions/typing.Optional
389 elif is_custom_class(_type):
390 # type must be C (custom class) at this point
391 value = _load_into_recurse(
392 # make mypy and pycharm happy by telling it _type is of type C...
393 # actually just passing _type as first arg!
394 typing.cast(Type_C[typing.Any], _type),
395 value,
396 convert_types=convert_types,
397 )
398 elif value := has_alias(cls, _key, data):
399 # value updated by alias
400 ...
401 elif _key in cls.__dict__:
402 # property has default, use that instead.
403 value = cls.__dict__[_key]
404 elif is_optional(_type):
405 # type is optional and not found in __dict__ -> default is None
406 value = None
407 elif dc.is_dataclass(cls) and (field := dataclass_field(cls, _key)) and field.default_factory is not dc.MISSING:
408 # could have a default factory
409 # todo: do something with field.default?
410 value = field.default_factory()
411 else:
412 raise ConfigErrorMissingKey(_key, cls, _type)
414 updated[_key] = value
416 return updated
419def check_and_convert_data(
420 cls: typing.Type[C],
421 data: dict[str, typing.Any],
422 _except: typing.Iterable[str],
423 strict: bool = True,
424 convert_types: bool = False,
425) -> dict[str, typing.Any]:
426 """
427 Based on class annotations, this prepares the data for `load_into_recurse`.
429 1. convert config-keys to python compatible config_keys
430 2. loads custom class type annotations with the same logic (see also `load_recursive`)
431 3. ensures the annotated types match the actual types after loading the config file.
432 """
433 annotations = all_annotations(cls, _except=_except)
435 to_load = convert_config(data)
436 to_load = load_recursive(cls, to_load, annotations, convert_types=convert_types)
438 if strict:
439 to_load = ensure_types(to_load, annotations, convert_types=convert_types)
441 return to_load
444T_init_list = list[typing.Any]
445T_init_dict = dict[str, typing.Any]
446T_init = tuple[T_init_list, T_init_dict] | T_init_list | T_init_dict | None
449@typing.no_type_check # (mypy doesn't understand 'match' fully yet)
450def _split_init(init: T_init) -> tuple[T_init_list, T_init_dict]:
451 """
452 Accept a tuple, a dict or a list of (arg, kwarg), {kwargs: ...}, [args] respectively and turn them all into a tuple.
453 """
454 if not init:
455 return [], {}
457 args: T_init_list = []
458 kwargs: T_init_dict = {}
459 match init:
460 case (args, kwargs):
461 return args, kwargs
462 case [*args]:
463 return args, {}
464 case {**kwargs}:
465 return [], kwargs
466 case _:
467 raise ValueError("Init must be either a tuple of list and dict, a list or a dict.")
470def _load_into_recurse(
471 cls: typing.Type[C],
472 data: dict[str, typing.Any] | bytes,
473 init: T_init = None,
474 strict: bool = True,
475 convert_types: bool = False,
476) -> C:
477 """
478 Loads an instance of `cls` filled with `data`.
480 Uses `load_recursive` to load any fillable annotated properties (see that method for an example).
481 `init` can be used to optionally pass extra __init__ arguments. \
482 NOTE: This will overwrite a config key with the same name!
483 """
484 init_args, init_kwargs = _split_init(init)
486 if isinstance(data, bytes) or issubclass(cls, BinaryConfig):
487 if not isinstance(data, (bytes, dict)): # pragma: no cover
488 raise NotImplementedError("BinaryConfig can only deal with `bytes` or a dict of bytes as input.")
489 elif not issubclass(cls, BinaryConfig): # pragma: no cover
490 raise NotImplementedError("Only BinaryConfig can be used with `bytes` (or a dict of bytes) as input.")
492 inst = typing.cast(C, cls._parse_into(data))
493 elif dc.is_dataclass(cls):
494 to_load = check_and_convert_data(cls, data, init_kwargs.keys(), strict=strict, convert_types=convert_types)
495 if init:
496 raise ValueError("Init is not allowed for dataclasses!")
498 # ensure mypy inst is an instance of the cls type (and not a fictuous `DataclassInstance`)
499 inst = typing.cast(C, cls(**to_load))
500 elif isinstance(data, cls):
501 # already the right type! (e.g. Pathlib)
502 inst = typing.cast(C, data)
503 else:
504 inst = cls(*init_args, **init_kwargs)
505 to_load = check_and_convert_data(cls, data, inst.__dict__.keys(), strict=strict, convert_types=convert_types)
506 inst.__dict__.update(**to_load)
508 return inst
511def _load_into_instance(
512 inst: C,
513 cls: typing.Type[C],
514 data: dict[str, typing.Any],
515 init: T_init = None,
516 strict: bool = True,
517 convert_types: bool = False,
518) -> C:
519 """
520 Similar to `load_into_recurse` but uses an existing instance of a class (so after __init__) \
521 and thus does not support init.
523 """
524 if init is not None:
525 raise ValueError("Can not init an existing instance!")
527 existing_data = inst.__dict__
529 to_load = check_and_convert_data(
530 cls, data, _except=existing_data.keys(), strict=strict, convert_types=convert_types
531 )
533 inst.__dict__.update(**to_load)
535 return inst
538def load_into_class(
539 cls: typing.Type[C],
540 data: T_data,
541 /,
542 key: str = None,
543 init: T_init = None,
544 strict: bool = True,
545 lower_keys: bool = False,
546 convert_types: bool = False,
547) -> C:
548 """
549 Shortcut for _load_data + load_into_recurse.
550 """
551 allow_types = (dict, bytes) if issubclass(cls, BinaryConfig) else (dict,)
552 to_load = load_data(data, key, cls.__name__, lower_keys=lower_keys, allow_types=allow_types)
553 return _load_into_recurse(cls, to_load, init=init, strict=strict, convert_types=convert_types)
556def load_into_instance(
557 inst: C,
558 data: T_data,
559 /,
560 key: str = None,
561 init: T_init = None,
562 strict: bool = True,
563 lower_keys: bool = False,
564 convert_types: bool = False,
565) -> C:
566 """
567 Shortcut for _load_data + load_into_existing.
568 """
569 cls = inst.__class__
570 allow_types = (dict, bytes) if issubclass(cls, BinaryConfig) else (dict,)
571 to_load = load_data(data, key, cls.__name__, lower_keys=lower_keys, allow_types=allow_types)
572 return _load_into_instance(inst, cls, to_load, init=init, strict=strict, convert_types=convert_types)
575def load_into(
576 cls: typing.Type[C],
577 data: T_data = None,
578 /,
579 key: str = None,
580 init: T_init = None,
581 strict: bool = True,
582 lower_keys: bool = False,
583 convert_types: bool = False,
584) -> C:
585 """
586 Load your config into a class (instance).
588 Supports both a class or an instance as first argument, but that's hard to explain to mypy, so officially only
589 classes are supported, and if you want to `load_into` an instance, you should use `load_into_instance`.
591 Args:
592 cls: either a class or an existing instance of that class.
593 data: can be a dictionary or a path to a file to load (as pathlib.Path or str)
594 key: optional (nested) dictionary key to load data from (e.g. 'tool.su6.specific')
595 init: optional data to pass to your cls' __init__ method (only if cls is not an instance already)
596 strict: enable type checks or allow anything?
597 lower_keys: should the config keys be lowercased? (for .env)
598 convert_types: should the types be converted to the annotated type if not yet matching? (for .env)
600 """
601 if not isinstance(cls, type):
602 # would not be supported according to mypy, but you can still load_into(instance)
603 return load_into_instance(
604 cls, data, key=key, init=init, strict=strict, lower_keys=lower_keys, convert_types=convert_types
605 )
607 # make mypy and pycharm happy by telling it cls is of type C and not just 'type'
608 # _cls = typing.cast(typing.Type[C], cls)
609 return load_into_class(
610 cls, data, key=key, init=init, strict=strict, lower_keys=lower_keys, convert_types=convert_types
611 )