Add Firebase Data Connect support

Author: lisajian

src/firebase_functions/dataconnect_fn.py

@@ -0,0 +1,278 @@
+# Copyright 2022 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+"""
+Module for Cloud Functions that are triggered by Firebase Data Connect.
+"""
+
+# pylint: disable=protected-access
+import dataclasses as _dataclass
+import datetime as _dt
+import functools as _functools
+import typing as _typing
+
+import cloudevents.http as _ce
+
+import firebase_functions.core as _core
+import firebase_functions.private.path_pattern as _path_pattern
+import firebase_functions.private.util as _util
+from firebase_functions.options import DataConnectOptions
+
+_event_type_mutation_executed = "google.firebase.dataconnect.connector.v1.mutationExecuted"
+
+
+@_dataclass.dataclass(frozen=True)
+class Event(_core.CloudEvent[_core.T]):
+    """
+    A CloudEvent that contains MutationEventData.
+    """
+
+    location: str
+    """
+    The location of the database.
+    """
+
+    project: str
+    """
+    The project identifier.
+    """
+
+    params: dict[str, str]
+    """
+    A dict containing the values of the path patterns.
+    Only named capture groups are populated - {key}, {key=*}, {key=**}
+    """
+
+
+@_dataclass.dataclass(frozen=True)
+class GraphqlErrorExtensions:
+    """
+    GraphqlErrorExtensions contains additional information of `GraphqlError`.
+    """
+
+    file: str
+    """
+    The source file name where the error occurred.
+    Included only for `UpdateSchema` and `UpdateConnector`, it corresponds
+    to `File.path` of the provided `Source`.
+    """
+
+    code: str
+    """
+    Maps to canonical gRPC codes.
+    If not specified, it represents `Code.INTERNAL`.
+    """
+
+    debug_details: str
+    """
+    More detailed error message to assist debugging.
+    It contains application business logic that are inappropriate to leak
+    publicly.
+
+    In the emulator, Data Connect API always includes it to assist local
+    development and debugging.
+    In the backend, ConnectorService always hides it.
+    GraphqlService without impersonation always include it.
+    GraphqlService with impersonation includes it only if explicitly opted-in
+    with `include_debug_details` in `GraphqlRequestExtensions`.
+    """
+
+
+@_dataclass.dataclass(frozen=True)
+class SourceLocation:
+    """
+    SourceLocation references a location in a GraphQL source.
+    """
+
+    line: int
+    """
+    Line number starting at 1.
+    """
+
+    column: int
+    """
+    Column number starting at 1.
+    """
+
+
+@_dataclass.dataclass(frozen=True)
+class GraphQLError:
+    """
+    An error that occurred during the execution of a GraphQL request.
+    """
+
+    message: str
+    """
+    A string describing the error.
+    """
+
+    locations: list[dict[str, int]] | None = None
+    """
+    The source locations where the error occurred.
+    Locations should help developers and toolings identify the source of error
+    quickly.
+
+    Included in admin endpoints (`ExecuteGraphql`, `ExecuteGraphqlRead`,
+    `UpdateSchema` and `UpdateConnector`) to reference the provided GraphQL
+    GQL document.
+
+    Omitted in `ExecuteMutation` and `ExecuteQuery` since the caller shouldn't
+    have access access the underlying GQL source.
+    """
+
+    path: list[str | int] | None = None
+    """
+    The result field which could not be populated due to error.
+
+    Clients can use path to identify whether a null result is intentional or
+    caused by a runtime error.
+    It should be a list of string or index from the root of GraphQL query
+    document.
+    """
+
+    extensions: GraphqlErrorExtensions | None = None
+
+
+@_dataclass.dataclass(frozen=True)
+class MutationEventData:
+    """
+    An object within Firebase Data Connect.
+    """
+
+    data: _typing.Any
+    """
+    The result of the execution of the requested operation.
+    If an error was raised before execution begins, the data entry should not
+    be present in the result. (a request error:
+    https://spec.graphql.org/draft/#sec-Errors.Request-Errors) If an error was
+    raised during the execution that prevented a valid response, the data entry
+    in the response should be null. (a field error:
+    https://spec.graphql.org/draft/#sec-Errors.Error-Result-Format)
+    """
+
+    variables: _typing.Any
+    """
+    Values for GraphQL variables provided in this request.
+    """
+
+    errors: list[GraphQLError] | None = None
+    """
+    Errors of this response.
+    If the data entry in the response is not present, the errors entry must be
+    present.
+    It conforms to https://spec.graphql.org/draft/#sec-Errors.
+    """
+
+
+_E1 = Event[MutationEventData]
+_C1 = _typing.Callable[[_E1], None]
+
+
+def _dataconnect_endpoint_handler(
+    func: _C1,
+    event_type: str,
+    service_pattern: _path_pattern.PathPattern,
+    connector_pattern: _path_pattern.PathPattern,
+    operation_pattern: _path_pattern.PathPattern,
+    raw: _ce.CloudEvent,
+) -> None:
+    # Currently, only mutationExecuted is supported
+    assert event_type == _event_type_mutation_executed
+
+    event_attributes = raw._get_attributes()
+    event_data: _typing.Any = raw.get_data()
+
+    dataconnect_event_data = event_data
+
+    event_service = event_attributes["service"]
+    event_connector = event_attributes["connector"]
+    event_operation = event_attributes["operation"]
+    params: dict[str, str] = {
+        **service_pattern.extract_matches(event_service),
+        **connector_pattern.extract_matches(event_connector),
+        **operation_pattern.extract_matches(event_operation),
+    }
+
+    dataconnect_event = Event(
+        specversion=event_attributes["specversion"],
+        id=event_attributes["id"],
+        source=event_attributes["source"],
+        type=event_attributes["type"],
+        time=_dt.datetime.strptime(
+            event_attributes["time"],
+            "%Y-%m-%dT%H:%M:%S.%f%z",
+        ),
+        subject=event_attributes.get("subject"),
+        location=event_attributes["location"],
+        project=event_attributes["project"],
+        params=params,
+        data=dataconnect_event_data,
+    )
+    _core._with_init(func)(dataconnect_event)
+
+
+@_util.copy_func_kwargs(DataConnectOptions)
+def on_mutation_executed(**kwargs) -> _typing.Callable[[_C1], _C1]:
+    """
+    Event handler that triggers when a mutation is executed in Firebase Data Connect.
+
+    Example:
+
+    .. code-block:: python
+
+      @on_mutation_executed(
+        service = "service-id",
+        connector = "connector-id",
+        operation = "mutation-name"
+      )
+      def mutation_executed_handler(event: Event[MutationEventData]):
+        pass
+
+    :param \\*\\*kwargs: DataConnect options.
+    :type \\*\\*kwargs: as :exc:`firebase_functions.options.DataConnectOptions`
+    :rtype: :exc:`typing.Callable`
+            \\[ \\[ :exc:`firebase_functions.dataconnect_fn.Event` \\[
+            :exc:`object` \\] \\], `None` \\]
+            A function that takes a DataConnect event and returns ``None``.
+    """
+    options = DataConnectOptions(**kwargs)
+
+    def on_mutation_executed_inner_decorator(func: _C1):
+        service_pattern = _path_pattern.PathPattern(options.service)
+        connector_pattern = _path_pattern.PathPattern(options.connector)
+        operation_pattern = _path_pattern.PathPattern(options.operation)
+
+        @_functools.wraps(func)
+        def on_mutation_executed_wrapped(raw: _ce.CloudEvent):
+            return _dataconnect_endpoint_handler(
+                func,
+                _event_type_mutation_executed,
+                service_pattern,
+                connector_pattern,
+                operation_pattern,
+                raw,
+            )
+
+        _util.set_func_endpoint_attr(
+            on_mutation_executed_wrapped,
+            options._endpoint(
+                event_type=_event_type_mutation_executed,
+                func_name=func.__name__,
+                service_pattern=service_pattern,
+                connector_pattern=connector_pattern,
+                operation_pattern=operation_pattern,
+            ),
+        )
+        return on_mutation_executed_wrapped
+
+    return on_mutation_executed_inner_decorator

src/firebase_functions/options.py

@@ -1152,6 +1152,73 @@ def _endpoint(
         return _manifest.ManifestEndpoint(**_typing.cast(dict, kwargs_merged))
 
 
+@_dataclasses.dataclass(frozen=True, kw_only=True)
+class DataConnectOptions(RuntimeOptions):
+    """
+    Options specific to Firebase Data Connect function types.
+    Internal use only.
+    """
+
+    service: str
+    """
+    The Firebase Data Connect service ID.
+    """
+
+    connector: str
+    """
+    The Firebase Data Connect connector ID.
+    """
+
+    operation: str
+    """
+    Name of the operation.
+    """
+
+    def _endpoint(
+        self,
+        **kwargs,
+    ) -> _manifest.ManifestEndpoint:
+        assert kwargs["event_type"] is not None
+        assert kwargs["service_pattern"] is not None
+        assert kwargs["connector_pattern"] is not None
+        assert kwargs["operation_pattern"] is not None
+
+        service_pattern: _path_pattern.PathPattern = kwargs["service_pattern"]
+        connector_pattern: _path_pattern.PathPattern = kwargs["connector_pattern"]
+        operation_pattern: _path_pattern.PathPattern = kwargs["operation_pattern"]
+
+        event_filters: _typing.Any = {}
+        event_filters_path_patterns: _typing.Any = {}
+
+        if service_pattern.has_wildcards:
+            event_filters_path_patterns["service"] = service_pattern.value
+        else:
+            event_filters["service"] = service_pattern.value
+
+        if connector_pattern.has_wildcards:
+            event_filters_path_patterns["connector"] = connector_pattern.value
+        else:
+            event_filters["connector"] = connector_pattern.value
+
+        if operation_pattern.has_wildcards:
+            event_filters_path_patterns["operation"] = operation_pattern.value
+        else:
+            event_filters["operation"] = operation_pattern.value
+
+        event_trigger = _manifest.EventTrigger(
+            eventType=kwargs["event_type"],
+            retry=False,
+            eventFilters=event_filters,
+            eventFilterPathPatterns=event_filters_path_patterns,
+        )
+
+        kwargs_merged = {
+            **_dataclasses.asdict(super()._endpoint(**kwargs)),
+            "eventTrigger": event_trigger,
+        }
+        return _manifest.ManifestEndpoint(**_typing.cast(dict, kwargs_merged))
+
+
 _GLOBAL_OPTIONS = RuntimeOptions()
 """The current default options for all functions. Internal use only."""