feat: use Mapping, not Dict for input arguments

Mapping imposes less restrictions on callers, because it's read-only and
allows non-dict types to be passed without copying them as dict(), or
passing dict-like values and ignoring the resulting type error.

Signed-off-by: Hal Blackburn <hwtb2@cam.ac.uk>

Author: h4l

cloudevents/abstract/event.py

@@ -32,7 +32,7 @@ class CloudEvent:
     @classmethod
     def create(
         cls: typing.Type[AnyCloudEvent],
-        attributes: typing.Dict[str, typing.Any],
+        attributes: typing.Mapping[str, typing.Any],
         data: typing.Optional[typing.Any],
     ) -> AnyCloudEvent:
         """

cloudevents/conversion.py

@@ -260,7 +260,7 @@ def best_effort_encode_attribute_value(value: typing.Any) -> typing.Any:
 
 def from_dict(
     event_type: typing.Type[AnyCloudEvent],
-    event: typing.Dict[str, typing.Any],
+    event: typing.Mapping[str, typing.Any],
 ) -> AnyCloudEvent:
     """
     Constructs an Event object of a given `event_type` from

cloudevents/http/conversion.py

@@ -58,7 +58,7 @@ def from_http(
 
 
 def from_dict(
-    event: typing.Dict[str, typing.Any],
+    event: typing.Mapping[str, typing.Any],
 ) -> CloudEvent:
     """
     Constructs a CloudEvent from a dict `event` representation.

cloudevents/http/event.py

@@ -34,11 +34,13 @@ class CloudEvent(abstract.CloudEvent):
 
     @classmethod
     def create(
-        cls, attributes: typing.Dict[str, typing.Any], data: typing.Optional[typing.Any]
+        cls,
+        attributes: typing.Mapping[str, typing.Any],
+        data: typing.Optional[typing.Any],
     ) -> "CloudEvent":
         return cls(attributes, data)
 
-    def __init__(self, attributes: typing.Dict[str, str], data: typing.Any = None):
+    def __init__(self, attributes: typing.Mapping[str, str], data: typing.Any = None):
         """
         Event Constructor
         :param attributes: a dict with cloudevent attributes. Minimally

cloudevents/pydantic/v1/conversion.py

@@ -63,7 +63,7 @@ def from_json(
 
 
 def from_dict(
-    event: typing.Dict[str, typing.Any],
+    event: typing.Mapping[str, typing.Any],
 ) -> CloudEvent:
     """
     Construct an CloudEvent from a dict `event` representation.

cloudevents/pydantic/v1/event.py

@@ -100,7 +100,9 @@ class CloudEvent(abstract.CloudEvent, BaseModel):  # type: ignore
 
     @classmethod
     def create(
-        cls, attributes: typing.Dict[str, typing.Any], data: typing.Optional[typing.Any]
+        cls,
+        attributes: typing.Mapping[str, typing.Any],
+        data: typing.Optional[typing.Any],
     ) -> "CloudEvent":
         return cls(attributes, data)
 
@@ -155,7 +157,7 @@ def create(
 
     def __init__(  # type: ignore[no-untyped-def]
         self,
-        attributes: typing.Optional[typing.Dict[str, typing.Any]] = None,
+        attributes: typing.Optional[typing.Mapping[str, typing.Any]] = None,
         data: typing.Optional[typing.Any] = None,
         **kwargs,
     ):

cloudevents/pydantic/v2/conversion.py

@@ -64,7 +64,7 @@ def from_json(
 
 
 def from_dict(
-    event: typing.Dict[str, typing.Any],
+    event: typing.Mapping[str, typing.Any],
 ) -> CloudEvent:
     """
     Construct an CloudEvent from a dict `event` representation.

cloudevents/pydantic/v2/event.py

@@ -44,7 +44,9 @@ class CloudEvent(abstract.CloudEvent, BaseModel):  # type: ignore
 
     @classmethod
     def create(
-        cls, attributes: typing.Dict[str, typing.Any], data: typing.Optional[typing.Any]
+        cls,
+        attributes: typing.Mapping[str, typing.Any],
+        data: typing.Optional[typing.Any],
     ) -> "CloudEvent":
         return cls(attributes, data)
 
@@ -103,7 +105,7 @@ def create(
 
     def __init__(  # type: ignore[no-untyped-def]
         self,
-        attributes: typing.Optional[typing.Dict[str, typing.Any]] = None,
+        attributes: typing.Optional[typing.Mapping[str, typing.Any]] = None,
         data: typing.Optional[typing.Any] = None,
         **kwargs,
     ):