Update pydantic to >= 2

Adapt codebase to use pydantic >= 2 models and functionalities.

Remove unneeded checks from `scripts-dev/check_pydantic_models.py`,
since pydantic can now be used in a strict mode which will prevent the
type coercion:
https://docs.pydantic.dev/2.0/usage/strict_mode/#type-coercions-in-strict-mode

Closes matrix-org#15858

pyproject.toml

@@ -205,7 +205,7 @@ matrix-common = "^1.3.0"
 packaging = ">=16.1"
 # This is the most recent version of Pydantic with available on common distros.
 # We are currently incompatible with >=2.0.0: (https://github.com/matrix-org/synapse/issues/15858)
-pydantic = "^1.7.4"
+pydantic = ">=2.0.0"
 
 # This is for building the rust components during "poetry install", which
 # currently ignores the `build-system.requires` directive (c.f.

scripts-dev/check_pydantic_models.py

@@ -36,11 +36,10 @@
 import traceback
 import unittest.mock
 from contextlib import contextmanager
-from typing import Any, Callable, Dict, Generator, List, Set, Type, TypeVar
+from typing import Callable, Dict, Generator, List, Set, TypeVar
 
 from parameterized import parameterized
 from pydantic import BaseModel as PydanticBaseModel, conbytes, confloat, conint, constr
-from pydantic.typing import get_args
 from typing_extensions import ParamSpec
 
 logger = logging.getLogger(__name__)
@@ -52,14 +51,6 @@
     confloat,
 ]
 
-TYPES_THAT_PYDANTIC_WILL_COERCE_TO = [
-    str,
-    bytes,
-    int,
-    float,
-    bool,
-]
-
 
 P = ParamSpec("P")
 R = TypeVar("R")
@@ -97,42 +88,12 @@ def wrapper(*args: P.args, **kwargs: P.kwargs) -> R:
     return wrapper
 
 
-def field_type_unwanted(type_: Any) -> bool:
-    """Very rough attempt to detect if a type is unwanted as a Pydantic annotation.
-
-    At present, we exclude types which will coerce, or any generic type involving types
-    which will coerce."""
-    logger.debug("Is %s unwanted?")
-    if type_ in TYPES_THAT_PYDANTIC_WILL_COERCE_TO:
-        logger.debug("yes")
-        return True
-    logger.debug("Maybe. Subargs are %s", get_args(type_))
-    rv = any(field_type_unwanted(t) for t in get_args(type_))
-    logger.debug("Conclusion: %s %s unwanted", type_, "is" if rv else "is not")
-    return rv
-
-
 class PatchedBaseModel(PydanticBaseModel):
     """A patched version of BaseModel that inspects fields after models are defined.
 
     We complain loudly if we see an unwanted type.
-
-    Beware: ModelField.type_ is presumably private; this is likely to be very brittle.
     """
 
-    @classmethod
-    def __init_subclass__(cls: Type[PydanticBaseModel], **kwargs: object):
-        for field in cls.__fields__.values():
-            # Note that field.type_ and field.outer_type are computed based on the
-            # annotation type, see pydantic.fields.ModelField._type_analysis
-            if field_type_unwanted(field.outer_type_):
-                # TODO: this only reports the first bad field. Can we find all bad ones
-                #  and report them all?
-                raise FieldHasUnwantedTypeException(
-                    f"{cls.__module__}.{cls.__qualname__} has field '{field.name}' "
-                    f"with unwanted type `{field.outer_type_}`"
-                )
-
 
 @contextmanager
 def monkeypatch_pydantic() -> Generator[None, None, None]:

synapse/config/_util.py

@@ -14,7 +14,7 @@
 from typing import Any, Dict, Type, TypeVar
 
 import jsonschema
-from pydantic import BaseModel, ValidationError, parse_obj_as
+from pydantic import BaseModel, TypeAdapter, ValidationError
 
 from synapse.config._base import ConfigError
 from synapse.types import JsonDict, StrSequence
@@ -86,7 +86,8 @@ def parse_and_validate_mapping(
     try:
         # type-ignore: mypy doesn't like constructing `Dict[str, model_type]` because
         # `model_type` is a runtime variable. Pydantic is fine with this.
-        instances = parse_obj_as(Dict[str, model_type], config)  # type: ignore[valid-type]
+        adapter = TypeAdapter(Dict[str, model_type])  # type: ignore[valid-type]
+        instances = adapter.validate_python(config, strict=True)
     except ValidationError as e:
         raise ConfigError(str(e)) from e
     return instances

synapse/config/workers.py

@@ -18,7 +18,7 @@
 from typing import Any, Dict, List, Optional, Union
 
 import attr
-from pydantic import BaseModel, Extra, StrictBool, StrictInt, StrictStr
+from pydantic import BaseModel, ConfigDict, StrictBool, StrictInt, StrictStr
 
 from synapse.config._base import (
     Config,
@@ -87,11 +87,7 @@ class ConfigModel(BaseModel):
     https://pydantic-docs.helpmanual.io/usage/model_config/#change-behaviour-globally
     """
 
-    class Config:
-        # By default, ignore fields that we don't recognise.
-        extra = Extra.ignore
-        # By default, don't allow fields to be reassigned after parsing.
-        allow_mutation = False
+    model_config = ConfigDict(extra="ignore", frozen=True)
 
 
 class InstanceTcpLocationConfig(ConfigModel):

synapse/http/servlet.py

@@ -29,8 +29,7 @@
     overload,
 )
 
-from pydantic import BaseModel, MissingError, PydanticValueError, ValidationError
-from pydantic.error_wrappers import ErrorWrapper
+from pydantic import BaseModel, ValidationError
 from typing_extensions import Literal
 
 from twisted.web.server import Request
@@ -786,20 +785,20 @@ def validate_json_object(content: JsonDict, model_type: Type[Model]) -> Model:
             if it wasn't a JSON object.
     """
     try:
-        instance = model_type.parse_obj(content)
+        instance = model_type.model_validate(content, strict=True)
     except ValidationError as e:
         # Choose a matrix error code. The catch-all is BAD_JSON, but we try to find a
         # more specific error if possible (which occasionally helps us to be spec-
         # compliant) This is a bit awkward because the spec's error codes aren't very
         # clear-cut: BAD_JSON arguably overlaps with MISSING_PARAM and INVALID_PARAM.
         errcode = Codes.BAD_JSON
 
-        raw_errors = e.raw_errors
-        if len(raw_errors) == 1 and isinstance(raw_errors[0], ErrorWrapper):
-            raw_error = raw_errors[0].exc
-            if isinstance(raw_error, MissingError):
+        raw_errors = e.errors()
+        if len(raw_errors) == 1:
+            error_type = raw_errors[0].get("type")
+            if error_type == "missing":
                 errcode = Codes.MISSING_PARAM
-            elif isinstance(raw_error, PydanticValueError):
+            else:
                 errcode = Codes.INVALID_PARAM
 
         raise SynapseError(HTTPStatus.BAD_REQUEST, str(e), errcode=errcode)

synapse/rest/client/devices.py

@@ -16,7 +16,7 @@
 import logging
 from typing import TYPE_CHECKING, List, Optional, Tuple
 
-from pydantic import Extra, StrictStr
+from pydantic import ConfigDict, StrictStr
 
 from synapse.api import errors
 from synapse.api.errors import NotFoundError, UnrecognizedRequestError
@@ -88,7 +88,7 @@ def __init__(self, hs: "HomeServer"):
         self.auth_handler = hs.get_auth_handler()
 
     class PostBody(RequestBodyModel):
-        auth: Optional[AuthenticationData]
+        auth: Optional[AuthenticationData] = None
         devices: List[StrictStr]
 
     @interactive_auth_handler
@@ -102,7 +102,7 @@ async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
                 # TODO: Can/should we remove this fallback now?
                 # deal with older clients which didn't pass a JSON dict
                 # the same as those that pass an empty dict
-                body = self.PostBody.parse_obj({})
+                body = self.PostBody.model_validate({}, strict=True)
             else:
                 raise e
 
@@ -161,7 +161,7 @@ async def on_GET(
         return 200, device
 
     class DeleteBody(RequestBodyModel):
-        auth: Optional[AuthenticationData]
+        auth: Optional[AuthenticationData] = None
 
     @interactive_auth_handler
     async def on_DELETE(
@@ -180,7 +180,7 @@ async def on_DELETE(
                 # TODO: can/should we remove this fallback now?
                 # deal with older clients which didn't pass a JSON dict
                 # the same as those that pass an empty dict
-                body = self.DeleteBody.parse_obj({})
+                body = self.DeleteBody.model_validate({}, strict=True)
             else:
                 raise
 
@@ -200,7 +200,7 @@ async def on_DELETE(
         return 200, {}
 
     class PutBody(RequestBodyModel):
-        display_name: Optional[StrictStr]
+        display_name: Optional[StrictStr] = None
 
     async def on_PUT(
         self, request: SynapseRequest, device_id: str
@@ -220,8 +220,7 @@ class DehydratedDeviceDataModel(RequestBodyModel):
     Expects other freeform fields. Use .dict() to access them.
     """
 
-    class Config:
-        extra = Extra.allow
+    model_config = ConfigDict(extra="allow")
 
     algorithm: StrictStr
 
@@ -285,7 +284,7 @@ async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
 
     class PutBody(RequestBodyModel):
         device_data: DehydratedDeviceDataModel
-        initial_device_display_name: Optional[StrictStr]
+        initial_device_display_name: Optional[StrictStr] = None
 
     async def on_PUT(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
         submission = parse_and_validate_json_object_from_request(request, self.PutBody)

synapse/rest/client/models.py

@@ -11,9 +11,16 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from typing import TYPE_CHECKING, Dict, Optional
+from typing import TYPE_CHECKING, Any, Dict, Optional
 
-from pydantic import Extra, StrictInt, StrictStr, constr, validator
+from pydantic import (
+    ConfigDict,
+    StrictInt,
+    StrictStr,
+    constr,
+    field_validator,
+    model_validator,
+)
 
 from synapse.rest.models import RequestBodyModel
 from synapse.util.threepids import validate_email
@@ -29,8 +36,7 @@ class AuthenticationData(RequestBodyModel):
     `.dict(exclude_unset=True)` to access them.
     """
 
-    class Config:
-        extra = Extra.allow
+    model_config = ConfigDict(extra="allow")
 
     session: Optional[StrictStr] = None
     type: Optional[StrictStr] = None
@@ -41,7 +47,7 @@ class Config:
 else:
     # See also assert_valid_client_secret()
     ClientSecretStr = constr(
-        regex="[0-9a-zA-Z.=_-]",  # noqa: F722
+        pattern="[0-9a-zA-Z.=_-]",  # noqa: F722
         min_length=1,
         max_length=255,
         strict=True,
@@ -50,18 +56,18 @@ class Config:
 
 class ThreepidRequestTokenBody(RequestBodyModel):
     client_secret: ClientSecretStr
-    id_server: Optional[StrictStr]
-    id_access_token: Optional[StrictStr]
-    next_link: Optional[StrictStr]
+    id_server: Optional[StrictStr] = None
+    id_access_token: Optional[StrictStr] = None
+    next_link: Optional[StrictStr] = None
     send_attempt: StrictInt
 
-    @validator("id_access_token", always=True)
-    def token_required_for_identity_server(
-        cls, token: Optional[str], values: Dict[str, object]
-    ) -> Optional[str]:
-        if values.get("id_server") is not None and token is None:
+    @model_validator(mode="before")
+    def token_required_for_identity_server(cls, data: Dict[str, Any]) -> Dict[str, Any]:
+        """Ensure that an access token is provided when a server is provided."""
+        if data.get("id_server") is not None and data.get("id_access_token") is None:
             raise ValueError("id_access_token is required if an id_server is supplied.")
-        return token
+
+        return data
 
 
 class EmailRequestTokenBody(ThreepidRequestTokenBody):
@@ -72,14 +78,14 @@ class EmailRequestTokenBody(ThreepidRequestTokenBody):
     # know the exact spelling (eg. upper and lower case) of address in the database.
     # Without this, an email stored in the database as "foo@bar.com" would cause
     # user requests for "FOO@bar.com" to raise a Not Found error.
-    _email_validator = validator("email", allow_reuse=True)(validate_email)
+    email_validator = field_validator("email")(validate_email)
 
 
 if TYPE_CHECKING:
     ISO3116_1_Alpha_2 = StrictStr
 else:
     # Per spec: two-letter uppercase ISO-3166-1-alpha-2
-    ISO3116_1_Alpha_2 = constr(regex="[A-Z]{2}", strict=True)
+    ISO3116_1_Alpha_2 = constr(pattern="[A-Z]{2}", strict=True)
 
 
 class MsisdnRequestTokenBody(ThreepidRequestTokenBody):

synapse/rest/models.py

@@ -1,4 +1,4 @@
-from pydantic import BaseModel, Extra
+from pydantic import BaseModel, ConfigDict
 
 
 class RequestBodyModel(BaseModel):
@@ -16,8 +16,4 @@ class RequestBodyModel(BaseModel):
     https://pydantic-docs.helpmanual.io/usage/model_config/#change-behaviour-globally
     """
 
-    class Config:
-        # By default, ignore fields that we don't recognise.
-        extra = Extra.ignore
-        # By default, don't allow fields to be reassigned after parsing.
-        allow_mutation = False
+    model_config = ConfigDict(extra="ignore", frozen=True)

synapse/storage/background_updates.py

@@ -900,7 +900,9 @@ async def validate_constraint_and_delete_in_background(
         #      match the constraint.
         #   3. We try re-validating the constraint.
 
-        parsed_progress = ValidateConstraintProgress.parse_obj(progress)
+        parsed_progress = ValidateConstraintProgress.model_validate(
+            progress, strict=True
+        )
 
         if parsed_progress.state == ValidateConstraintProgress.State.check:
             return_columns = ", ".join(unique_columns)

tests/rest/client/test_account.py

@@ -794,21 +794,21 @@ def test_add_valid_email_second_time_canonicalise(self) -> None:
     def test_add_email_no_at(self) -> None:
         self._request_token_invalid_email(
             "address-without-at.bar",
-            expected_errcode=Codes.BAD_JSON,
+            expected_errcode=Codes.INVALID_PARAM,
             expected_error="Unable to parse email address",
         )
 
     def test_add_email_two_at(self) -> None:
         self._request_token_invalid_email(
             "foo@foo@test.bar",
-            expected_errcode=Codes.BAD_JSON,
+            expected_errcode=Codes.INVALID_PARAM,
             expected_error="Unable to parse email address",
         )
 
     def test_add_email_bad_format(self) -> None:
         self._request_token_invalid_email(
             "user@bad.example.net@good.example.com",
-            expected_errcode=Codes.BAD_JSON,
+            expected_errcode=Codes.INVALID_PARAM,
             expected_error="Unable to parse email address",
         )