Your IP : 3.145.99.221
from __future__ import annotations
import collections
import contextlib
import os.path
import re
import sys
class ValidationError(ValueError):
def __init__(self, error_msg, ctx=None):
super().__init__(error_msg)
self.error_msg = error_msg
self.ctx = ctx
def __str__(self):
out = '\n'
err = self
while err.ctx is not None:
out += f'==> {err.ctx}\n'
err = err.error_msg
out += f'=====> {err.error_msg}'
return out
MISSING = collections.namedtuple('Missing', ())()
type(MISSING).__repr__ = lambda self: 'MISSING'
@contextlib.contextmanager
def validate_context(msg):
try:
yield
except ValidationError as e:
_, _, tb = sys.exc_info()
raise ValidationError(e, ctx=msg).with_traceback(tb) from None
@contextlib.contextmanager
def reraise_as(tp):
try:
yield
except ValidationError as e:
_, _, tb = sys.exc_info()
raise tp(e).with_traceback(tb) from None
def _dct_noop(self, dct):
pass
def _check_optional(self, dct):
if self.key not in dct:
return
with validate_context(f'At key: {self.key}'):
self.check_fn(dct[self.key])
def _apply_default_optional(self, dct):
dct.setdefault(self.key, self.default)
def _remove_default_optional(self, dct):
if dct.get(self.key, MISSING) == self.default:
del dct[self.key]
def _require_key(self, dct):
if self.key not in dct:
raise ValidationError(f'Missing required key: {self.key}')
def _check_required(self, dct):
_require_key(self, dct)
_check_optional(self, dct)
@property
def _check_fn_recurse(self):
def check_fn(val):
validate(val, self.schema)
return check_fn
def _apply_default_required_recurse(self, dct):
dct[self.key] = apply_defaults(dct[self.key], self.schema)
def _remove_default_required_recurse(self, dct):
dct[self.key] = remove_defaults(dct[self.key], self.schema)
def _apply_default_optional_recurse(self, dct):
if self.key not in dct:
_apply_default_optional(self, dct)
_apply_default_required_recurse(self, dct)
def _remove_default_optional_recurse(self, dct):
if self.key in dct:
_remove_default_required_recurse(self, dct)
_remove_default_optional(self, dct)
def _get_check_conditional(inner):
def _check_conditional(self, dct):
if dct.get(self.condition_key, MISSING) == self.condition_value:
inner(self, dct)
elif (
self.condition_key in dct and
self.ensure_absent and self.key in dct
):
if hasattr(self.condition_value, 'describe_opposite'):
explanation = self.condition_value.describe_opposite()
else:
explanation = f'is not {self.condition_value!r}'
raise ValidationError(
f'Expected {self.key} to be absent when {self.condition_key} '
f'{explanation}, found {self.key}: {dct[self.key]!r}',
)
return _check_conditional
def _apply_default_conditional_optional(self, dct):
if dct.get(self.condition_key, MISSING) == self.condition_value:
_apply_default_optional(self, dct)
def _remove_default_conditional_optional(self, dct):
if dct.get(self.condition_key, MISSING) == self.condition_value:
_remove_default_optional(self, dct)
def _apply_default_conditional_recurse(self, dct):
if dct.get(self.condition_key, MISSING) == self.condition_value:
_apply_default_required_recurse(self, dct)
def _remove_default_conditional_recurse(self, dct):
if dct.get(self.condition_key, MISSING) == self.condition_value:
_remove_default_required_recurse(self, dct)
def _no_additional_keys_check(self, dct):
extra = sorted(set(dct) - set(self.keys))
if extra:
extra_s = ', '.join(str(x) for x in extra)
keys_s = ', '.join(str(x) for x in self.keys)
raise ValidationError(
f'Additional keys found: {extra_s}. '
f'Only these keys are allowed: {keys_s}',
)
def _warn_additional_keys_check(self, dct):
extra = sorted(set(dct) - set(self.keys))
if extra:
self.callback(extra, self.keys, dct)
Required = collections.namedtuple('Required', ('key', 'check_fn'))
Required.check = _check_required
Required.apply_default = _dct_noop
Required.remove_default = _dct_noop
RequiredRecurse = collections.namedtuple('RequiredRecurse', ('key', 'schema'))
RequiredRecurse.check = _check_required
RequiredRecurse.check_fn = _check_fn_recurse
RequiredRecurse.apply_default = _apply_default_required_recurse
RequiredRecurse.remove_default = _remove_default_required_recurse
Optional = collections.namedtuple('Optional', ('key', 'check_fn', 'default'))
Optional.check = _check_optional
Optional.apply_default = _apply_default_optional
Optional.remove_default = _remove_default_optional
OptionalRecurse = collections.namedtuple(
'OptionalRecurse', ('key', 'schema', 'default'),
)
OptionalRecurse.check = _check_optional
OptionalRecurse.check_fn = _check_fn_recurse
OptionalRecurse.apply_default = _apply_default_optional_recurse
OptionalRecurse.remove_default = _remove_default_optional_recurse
OptionalNoDefault = collections.namedtuple(
'OptionalNoDefault', ('key', 'check_fn'),
)
OptionalNoDefault.check = _check_optional
OptionalNoDefault.apply_default = _dct_noop
OptionalNoDefault.remove_default = _dct_noop
Conditional = collections.namedtuple(
'Conditional',
('key', 'check_fn', 'condition_key', 'condition_value', 'ensure_absent'),
)
Conditional.__new__.__defaults__ = (False,)
Conditional.check = _get_check_conditional(_check_required)
Conditional.apply_default = _dct_noop
Conditional.remove_default = _dct_noop
ConditionalOptional = collections.namedtuple(
'ConditionalOptional',
(
'key', 'check_fn', 'default', 'condition_key', 'condition_value',
'ensure_absent',
),
)
ConditionalOptional.__new__.__defaults__ = (False,)
ConditionalOptional.check = _get_check_conditional(_check_optional)
ConditionalOptional.apply_default = _apply_default_conditional_optional
ConditionalOptional.remove_default = _remove_default_conditional_optional
ConditionalRecurse = collections.namedtuple(
'ConditionalRecurse',
('key', 'schema', 'condition_key', 'condition_value', 'ensure_absent'),
)
ConditionalRecurse.__new__.__defaults__ = (False,)
ConditionalRecurse.check = _get_check_conditional(_check_required)
ConditionalRecurse.check_fn = _check_fn_recurse
ConditionalRecurse.apply_default = _apply_default_conditional_recurse
ConditionalRecurse.remove_default = _remove_default_conditional_recurse
NoAdditionalKeys = collections.namedtuple('NoAdditionalKeys', ('keys',))
NoAdditionalKeys.check = _no_additional_keys_check
NoAdditionalKeys.apply_default = _dct_noop
NoAdditionalKeys.remove_default = _dct_noop
WarnAdditionalKeys = collections.namedtuple(
'WarnAdditionalKeys', ('keys', 'callback'),
)
WarnAdditionalKeys.check = _warn_additional_keys_check
WarnAdditionalKeys.apply_default = _dct_noop
WarnAdditionalKeys.remove_default = _dct_noop
class Map(collections.namedtuple('Map', ('object_name', 'id_key', 'items'))):
__slots__ = ()
def __new__(cls, object_name, id_key, *items):
return super().__new__(cls, object_name, id_key, items)
def check(self, v):
if not isinstance(v, dict):
raise ValidationError(
f'Expected a {self.object_name} map but got a '
f'{type(v).__name__}',
)
if self.id_key is None:
context = f'At {self.object_name}()'
else:
key_v_s = v.get(self.id_key, MISSING)
context = f'At {self.object_name}({self.id_key}={key_v_s!r})'
with validate_context(context):
for item in self.items:
item.check(v)
def apply_defaults(self, v):
ret = v.copy()
for item in self.items:
item.apply_default(ret)
return ret
def remove_defaults(self, v):
ret = v.copy()
for item in self.items:
item.remove_default(ret)
return ret
class Array(collections.namedtuple('Array', ('of', 'allow_empty'))):
__slots__ = ()
def __new__(cls, of, allow_empty=True):
return super().__new__(cls, of=of, allow_empty=allow_empty)
def check(self, v):
check_array(check_any)(v)
if not self.allow_empty and not v:
raise ValidationError(
f"Expected at least 1 '{self.of.object_name}'",
)
for val in v:
validate(val, self.of)
def apply_defaults(self, v):
return [apply_defaults(val, self.of) for val in v]
def remove_defaults(self, v):
return [remove_defaults(val, self.of) for val in v]
class Not(collections.namedtuple('Not', ('val',))):
__slots__ = ()
def describe_opposite(self):
return f'is {self.val!r}'
def __eq__(self, other):
return other is not MISSING and other != self.val
class NotIn(collections.namedtuple('NotIn', ('values',))):
__slots__ = ()
def __new__(cls, *values):
return super().__new__(cls, values=values)
def describe_opposite(self):
return f'is any of {self.values!r}'
def __eq__(self, other):
return other is not MISSING and other not in self.values
class In(collections.namedtuple('In', ('values',))):
__slots__ = ()
def __new__(cls, *values):
return super().__new__(cls, values=values)
def describe_opposite(self):
return f'is not any of {self.values!r}'
def __eq__(self, other):
return other is not MISSING and other in self.values
def check_any(_):
pass
def check_type(tp, typename=None):
def check_type_fn(v):
if not isinstance(v, tp):
typename_s = typename or tp.__name__
raise ValidationError(
f'Expected {typename_s} got {type(v).__name__}',
)
return check_type_fn
check_bool = check_type(bool)
check_bytes = check_type(bytes)
check_int = check_type(int)
check_string = check_type(str, typename='string')
check_text = check_type(str, typename='text')
def check_one_of(possible):
def check_one_of_fn(v):
if v not in possible:
possible_s = ', '.join(str(x) for x in sorted(possible))
raise ValidationError(
f'Expected one of {possible_s} but got: {v!r}',
)
return check_one_of_fn
def check_regex(v):
try:
re.compile(v)
except re.error:
raise ValidationError(f'{v!r} is not a valid python regex')
def check_array(inner_check):
def check_array_fn(v):
if not isinstance(v, (list, tuple)):
raise ValidationError(
f'Expected array but got {type(v).__name__!r}',
)
for i, val in enumerate(v):
with validate_context(f'At index {i}'):
inner_check(val)
return check_array_fn
def check_and(*fns):
def check(v):
for fn in fns:
fn(v)
return check
def validate(v, schema):
schema.check(v)
return v
def apply_defaults(v, schema):
return schema.apply_defaults(v)
def remove_defaults(v, schema):
return schema.remove_defaults(v)
def load_from_filename(
filename,
schema,
load_strategy,
exc_tp=ValidationError,
*,
display_filename=None,
):
display_filename = display_filename or filename
with reraise_as(exc_tp):
if not os.path.isfile(filename):
raise ValidationError(f'{display_filename} is not a file')
with validate_context(f'File {display_filename}'):
try:
with open(filename, encoding='utf-8') as f:
contents = f.read()
except UnicodeDecodeError as e:
raise ValidationError(str(e))
try:
data = load_strategy(contents)
except Exception as e:
raise ValidationError(str(e))
validate(data, schema)
return apply_defaults(data, schema)