zulip/zerver/lib/validator.py

559 lines
18 KiB
Python

"""
This module sets up a scheme for validating that arbitrary Python
objects are correctly typed. It is totally decoupled from Django,
composable, easily wrapped, and easily extended.
A validator takes two parameters--var_name and val--and raises an
error if val is not the correct type. The var_name parameter is used
to format error messages. Validators return the validated value when
there are no errors.
Example primitive validators are check_string, check_int, and check_bool.
Compound validators are created by check_list and check_dict. Note that
those functions aren't directly called for validation; instead, those
functions are called to return other functions that adhere to the validator
contract. This is similar to how Python decorators are often parameterized.
The contract for check_list and check_dict is that they get passed in other
validators to apply to their items. This allows you to build up validators
for arbitrarily complex validators. See ValidatorTestCase for example usage.
A simple example of composition is this:
check_list(check_string)('my_list', ['a', 'b', 'c'])
To extend this concept, it's simply a matter of writing your own validator
for any particular type of object.
"""
import re
from datetime import datetime
from typing import (
Any,
Callable,
Collection,
Dict,
List,
Optional,
Set,
Tuple,
TypeVar,
Union,
cast,
overload,
)
import orjson
from django.core.exceptions import ValidationError
from django.core.validators import URLValidator, validate_email
from django.utils.translation import gettext as _
from zerver.lib.request import JsonableError, ResultT
from zerver.lib.types import ProfileFieldData, Validator
def check_string(var_name: str, val: object) -> str:
if not isinstance(val, str):
raise ValidationError(_("{var_name} is not a string").format(var_name=var_name))
return val
def check_required_string(var_name: str, val: object) -> str:
s = check_string(var_name, val)
if not s.strip():
raise ValidationError(_("{item} cannot be blank.").format(item=var_name))
return s
def check_string_in(possible_values: Union[Set[str], List[str]]) -> Validator[str]:
def validator(var_name: str, val: object) -> str:
s = check_string(var_name, val)
if s not in possible_values:
raise ValidationError(_("Invalid {var_name}").format(var_name=var_name))
return s
return validator
def check_short_string(var_name: str, val: object) -> str:
return check_capped_string(50)(var_name, val)
def check_capped_string(max_length: int) -> Validator[str]:
def validator(var_name: str, val: object) -> str:
s = check_string(var_name, val)
if len(s) > max_length:
raise ValidationError(
_("{var_name} is too long (limit: {max_length} characters)").format(
var_name=var_name,
max_length=max_length,
)
)
return s
return validator
def check_string_fixed_length(length: int) -> Validator[str]:
def validator(var_name: str, val: object) -> str:
s = check_string(var_name, val)
if len(s) != length:
raise ValidationError(
_("{var_name} has incorrect length {length}; should be {target_length}").format(
var_name=var_name,
target_length=length,
length=len(s),
)
)
return s
return validator
def check_long_string(var_name: str, val: object) -> str:
return check_capped_string(500)(var_name, val)
def check_date(var_name: str, val: object) -> str:
if not isinstance(val, str):
raise ValidationError(_("{var_name} is not a string").format(var_name=var_name))
try:
if datetime.strptime(val, "%Y-%m-%d").strftime("%Y-%m-%d") != val:
raise ValidationError(_("{var_name} is not a date").format(var_name=var_name))
except ValueError:
raise ValidationError(_("{var_name} is not a date").format(var_name=var_name))
return val
def check_int(var_name: str, val: object) -> int:
if not isinstance(val, int):
raise ValidationError(_("{var_name} is not an integer").format(var_name=var_name))
return val
def check_int_in(possible_values: List[int]) -> Validator[int]:
def validator(var_name: str, val: object) -> int:
n = check_int(var_name, val)
if n not in possible_values:
raise ValidationError(_("Invalid {var_name}").format(var_name=var_name))
return n
return validator
def check_float(var_name: str, val: object) -> float:
if not isinstance(val, float):
raise ValidationError(_("{var_name} is not a float").format(var_name=var_name))
return val
def check_bool(var_name: str, val: object) -> bool:
if not isinstance(val, bool):
raise ValidationError(_("{var_name} is not a boolean").format(var_name=var_name))
return val
def check_color(var_name: str, val: object) -> str:
s = check_string(var_name, val)
valid_color_pattern = re.compile(r"^#([a-fA-F0-9]{3,6})$")
matched_results = valid_color_pattern.match(s)
if not matched_results:
raise ValidationError(
_("{var_name} is not a valid hex color code").format(var_name=var_name)
)
return s
def check_none_or(sub_validator: Validator[ResultT]) -> Validator[Optional[ResultT]]:
def f(var_name: str, val: object) -> Optional[ResultT]:
if val is None:
return val
else:
return sub_validator(var_name, val)
return f
def check_list(
sub_validator: Validator[ResultT], length: Optional[int] = None
) -> Validator[List[ResultT]]:
def f(var_name: str, val: object) -> List[ResultT]:
if not isinstance(val, list):
raise ValidationError(_("{var_name} is not a list").format(var_name=var_name))
if length is not None and length != len(val):
raise ValidationError(
_("{container} should have exactly {length} items").format(
container=var_name,
length=length,
)
)
for i, item in enumerate(val):
vname = f"{var_name}[{i}]"
valid_item = sub_validator(vname, item)
assert item is valid_item # To justify the unchecked cast below
return cast(List[ResultT], val)
return f
def check_tuple(sub_validators: List[Validator[ResultT]]) -> Validator[Tuple[Any, ...]]:
def f(var_name: str, val: object) -> Tuple[Any, ...]:
if not isinstance(val, tuple):
raise ValidationError(_("{var_name} is not a tuple").format(var_name=var_name))
desired_len = len(sub_validators)
if desired_len != len(val):
raise ValidationError(
_("{var_name} should have exactly {desired_len} items").format(
var_name=var_name,
desired_len=desired_len,
)
)
for i, sub_validator in enumerate(sub_validators):
vname = f"{var_name}[{i}]"
sub_validator(vname, val[i])
return val
return f
# https://zulip.readthedocs.io/en/latest/testing/mypy.html#using-overload-to-accurately-describe-variations
@overload
def check_dict(
required_keys: Collection[Tuple[str, Validator[object]]] = [],
optional_keys: Collection[Tuple[str, Validator[object]]] = [],
*,
_allow_only_listed_keys: bool = False,
) -> Validator[Dict[str, object]]:
...
@overload
def check_dict(
required_keys: Collection[Tuple[str, Validator[ResultT]]] = [],
optional_keys: Collection[Tuple[str, Validator[ResultT]]] = [],
*,
value_validator: Validator[ResultT],
_allow_only_listed_keys: bool = False,
) -> Validator[Dict[str, ResultT]]:
...
def check_dict(
required_keys: Collection[Tuple[str, Validator[ResultT]]] = [],
optional_keys: Collection[Tuple[str, Validator[ResultT]]] = [],
*,
value_validator: Optional[Validator[ResultT]] = None,
_allow_only_listed_keys: bool = False,
) -> Validator[Dict[str, ResultT]]:
def f(var_name: str, val: object) -> Dict[str, ResultT]:
if not isinstance(val, dict):
raise ValidationError(_("{var_name} is not a dict").format(var_name=var_name))
for k in val:
check_string(f"{var_name} key", k)
for k, sub_validator in required_keys:
if k not in val:
raise ValidationError(
_("{key_name} key is missing from {var_name}").format(
key_name=k,
var_name=var_name,
)
)
vname = f'{var_name}["{k}"]'
sub_validator(vname, val[k])
for k, sub_validator in optional_keys:
if k in val:
vname = f'{var_name}["{k}"]'
sub_validator(vname, val[k])
if value_validator:
for key in val:
vname = f"{var_name} contains a value that"
valid_value = value_validator(vname, val[key])
assert val[key] is valid_value # To justify the unchecked cast below
if _allow_only_listed_keys:
required_keys_set = {x[0] for x in required_keys}
optional_keys_set = {x[0] for x in optional_keys}
delta_keys = set(val.keys()) - required_keys_set - optional_keys_set
if len(delta_keys) != 0:
raise ValidationError(
_("Unexpected arguments: {}").format(", ".join(list(delta_keys)))
)
return cast(Dict[str, ResultT], val)
return f
def check_dict_only(
required_keys: Collection[Tuple[str, Validator[ResultT]]],
optional_keys: Collection[Tuple[str, Validator[ResultT]]] = [],
) -> Validator[Dict[str, ResultT]]:
return cast(
Validator[Dict[str, ResultT]],
check_dict(required_keys, optional_keys, _allow_only_listed_keys=True),
)
def check_union(allowed_type_funcs: Collection[Validator[ResultT]]) -> Validator[ResultT]:
"""
Use this validator if an argument is of a variable type (e.g. processing
properties that might be strings or booleans).
`allowed_type_funcs`: the check_* validator functions for the possible data
types for this variable.
"""
def enumerated_type_check(var_name: str, val: object) -> ResultT:
for func in allowed_type_funcs:
try:
return func(var_name, val)
except ValidationError:
pass
raise ValidationError(_("{var_name} is not an allowed_type").format(var_name=var_name))
return enumerated_type_check
def equals(expected_val: ResultT) -> Validator[ResultT]:
def f(var_name: str, val: object) -> ResultT:
if val != expected_val:
raise ValidationError(
_("{variable} != {expected_value} ({value} is wrong)").format(
variable=var_name,
expected_value=expected_val,
value=val,
)
)
return cast(ResultT, val)
return f
def validate_login_email(email: str) -> None:
try:
validate_email(email)
except ValidationError as err:
raise JsonableError(str(err.message))
def check_url(var_name: str, val: object) -> str:
# First, ensure val is a string
s = check_string(var_name, val)
# Now, validate as URL
validate = URLValidator()
try:
validate(s)
return s
except ValidationError:
raise ValidationError(_("{var_name} is not a URL").format(var_name=var_name))
def check_external_account_url_pattern(var_name: str, val: object) -> str:
s = check_string(var_name, val)
if s.count("%(username)s") != 1:
raise ValidationError(_("Malformed URL pattern."))
url_val = s.replace("%(username)s", "username")
check_url(var_name, url_val)
return s
def validate_select_field_data(field_data: ProfileFieldData) -> Dict[str, Dict[str, str]]:
"""
This function is used to validate the data sent to the server while
creating/editing choices of the choice field in Organization settings.
"""
validator = check_dict_only(
[
("text", check_required_string),
("order", check_required_string),
]
)
for key, value in field_data.items():
if not key.strip():
raise ValidationError(_("'{item}' cannot be blank.").format(item="value"))
valid_value = validator("field_data", value)
assert value is valid_value # To justify the unchecked cast below
return cast(Dict[str, Dict[str, str]], field_data)
def validate_select_field(var_name: str, field_data: str, value: object) -> str:
"""
This function is used to validate the value selected by the user against a
choice field. This is not used to validate admin data.
"""
s = check_string(var_name, value)
field_data_dict = orjson.loads(field_data)
if s not in field_data_dict:
msg = _("'{value}' is not a valid choice for '{field_name}'.")
raise ValidationError(msg.format(value=value, field_name=var_name))
return s
def check_widget_content(widget_content: object) -> Dict[str, Any]:
if not isinstance(widget_content, dict):
raise ValidationError("widget_content is not a dict")
if "widget_type" not in widget_content:
raise ValidationError("widget_type is not in widget_content")
if "extra_data" not in widget_content:
raise ValidationError("extra_data is not in widget_content")
widget_type = widget_content["widget_type"]
extra_data = widget_content["extra_data"]
if not isinstance(extra_data, dict):
raise ValidationError("extra_data is not a dict")
if widget_type == "zform":
if "type" not in extra_data:
raise ValidationError("zform is missing type field")
if extra_data["type"] == "choices":
check_choices = check_list(
check_dict(
[
("short_name", check_string),
("long_name", check_string),
("reply", check_string),
]
),
)
# We re-check "type" here just to avoid it looking
# like we have extraneous keys.
checker = check_dict(
[
("type", equals("choices")),
("heading", check_string),
("choices", check_choices),
]
)
checker("extra_data", extra_data)
return widget_content
raise ValidationError("unknown zform type: " + extra_data["type"])
raise ValidationError("unknown widget type: " + widget_type)
def validate_poll_data(poll_data: object, is_widget_author: bool) -> None:
check_dict([("type", check_string)])("poll data", poll_data)
assert isinstance(poll_data, dict)
if poll_data["type"] == "vote":
checker = check_dict_only(
[
("type", check_string),
("key", check_string),
("vote", check_int_in([1, -1])),
]
)
checker("poll data", poll_data)
return
if poll_data["type"] == "question":
if not is_widget_author:
raise ValidationError("You can't edit a question unless you are the author.")
checker = check_dict_only(
[
("type", check_string),
("question", check_string),
]
)
checker("poll data", poll_data)
return
if poll_data["type"] == "new_option":
checker = check_dict_only(
[
("type", check_string),
("option", check_string),
("idx", check_int),
]
)
checker("poll data", poll_data)
return
raise ValidationError(f"Unknown type for poll data: {poll_data['type']}")
# Converter functions for use with has_request_variables
def to_non_negative_int(s: str, max_int_size: int = 2 ** 32 - 1) -> int:
x = int(s)
if x < 0:
raise ValueError("argument is negative")
if x > max_int_size:
raise ValueError(f"{x} is too large (max {max_int_size})")
return x
def to_positive_or_allowed_int(allowed_integer: Optional[int] = None) -> Callable[[str], int]:
def converter(s: str) -> int:
x = int(s)
if allowed_integer is not None and x == allowed_integer:
return x
if x == 0:
raise ValueError("argument is 0")
return to_non_negative_int(s)
return converter
def check_string_or_int_list(var_name: str, val: object) -> Union[str, List[int]]:
if isinstance(val, str):
return val
if not isinstance(val, list):
raise ValidationError(
_("{var_name} is not a string or an integer list").format(var_name=var_name)
)
return check_list(check_int)(var_name, val)
def check_string_or_int(var_name: str, val: object) -> Union[str, int]:
if isinstance(val, (str, int)):
return val
raise ValidationError(_("{var_name} is not a string or integer").format(var_name=var_name))
TypeA = TypeVar("TypeA")
TypeB = TypeVar("TypeB")
def check_or(
sub_validator1: Validator[TypeA], sub_validator2: Validator[TypeB]
) -> Validator[Union[TypeA, TypeB]]:
def f(var_name: str, val: object) -> Union[TypeA, TypeB]:
try:
return sub_validator1(var_name, val)
except ValidationError:
pass
return sub_validator2(var_name, val)
return f