Added generic to textmap getter and setter (#2657)

* added generic to textmap getter and setter

* added CHANGELOG entry

Co-authored-by: Srikanth Chekuri <srikanth.chekuri92@gmail.com>

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://github.com/open-telemetry/opentelemetry-python/compare/v1.12.0rc1-0.31b0...HEAD)
 
+- Fix type hints for textmap `Getter` and `Setter`
+  ([#2657](https://github.com/open-telemetry/opentelemetry-python/pull/2657))
 - Fix LogEmitterProvider.force_flush hanging randomly
   ([#2714](https://github.com/open-telemetry/opentelemetry-python/pull/2714))
 - narrow protobuf dependencies to exclude protobuf >= 4

opentelemetry-api/src/opentelemetry/baggage/propagation/__init__.py

@@ -38,7 +38,7 @@ def extract(
         self,
         carrier: textmap.CarrierT,
         context: Optional[Context] = None,
-        getter: textmap.Getter = textmap.default_getter,
+        getter: textmap.Getter[textmap.CarrierT] = textmap.default_getter,
     ) -> Context:
         """Extract Baggage from the carrier.
 
@@ -109,7 +109,7 @@ def inject(
         self,
         carrier: textmap.CarrierT,
         context: Optional[Context] = None,
-        setter: textmap.Setter = textmap.default_setter,
+        setter: textmap.Setter[textmap.CarrierT] = textmap.default_setter,
     ) -> None:
         """Injects Baggage into the carrier.
 

opentelemetry-api/src/opentelemetry/propagate/__init__.py

@@ -84,7 +84,7 @@ def example_route():
 def extract(
     carrier: textmap.CarrierT,
     context: typing.Optional[Context] = None,
-    getter: textmap.Getter = textmap.default_getter,
+    getter: textmap.Getter[textmap.CarrierT] = textmap.default_getter,
 ) -> Context:
     """Uses the configured propagator to extract a Context from the carrier.
 
@@ -105,7 +105,7 @@ def extract(
 def inject(
     carrier: textmap.CarrierT,
     context: typing.Optional[Context] = None,
-    setter: textmap.Setter = textmap.default_setter,
+    setter: textmap.Setter[textmap.CarrierT] = textmap.default_setter,
 ) -> None:
     """Uses the configured propagator to inject a Context into the carrier.
 

opentelemetry-api/src/opentelemetry/propagators/composite.py

@@ -39,7 +39,7 @@ def extract(
         self,
         carrier: textmap.CarrierT,
         context: typing.Optional[Context] = None,
-        getter: textmap.Getter = textmap.default_getter,
+        getter: textmap.Getter[textmap.CarrierT] = textmap.default_getter,
     ) -> Context:
         """Run each of the configured propagators with the given context and carrier.
         Propagators are run in the order they are configured, if multiple
@@ -56,7 +56,7 @@ def inject(
         self,
         carrier: textmap.CarrierT,
         context: typing.Optional[Context] = None,
-        setter: textmap.Setter = textmap.default_setter,
+        setter: textmap.Setter[textmap.CarrierT] = textmap.default_setter,
     ) -> None:
         """Run each of the configured propagators with the given context and carrier.
         Propagators are run in the order they are configured, if multiple

opentelemetry-api/src/opentelemetry/propagators/textmap.py

@@ -21,7 +21,7 @@
 CarrierValT = typing.Union[typing.List[str], str]
 
 
-class Getter(abc.ABC):
+class Getter(abc.ABC, typing.Generic[CarrierT]):
     """This class implements a Getter that enables extracting propagated
     fields from a carrier.
     """
@@ -54,7 +54,7 @@ def keys(self, carrier: CarrierT) -> typing.List[str]:
         """
 
 
-class Setter(abc.ABC):
+class Setter(abc.ABC, typing.Generic[CarrierT]):
     """This class implements a Setter that enables injecting propagated
     fields into a carrier.
     """
@@ -71,8 +71,8 @@ def set(self, carrier: CarrierT, key: str, value: str) -> None:
         """
 
 
-class DefaultGetter(Getter):
-    def get(  # type: ignore
+class DefaultGetter(Getter[typing.Mapping[str, CarrierValT]]):
+    def get(
         self, carrier: typing.Mapping[str, CarrierValT], key: str
     ) -> typing.Optional[typing.List[str]]:
         """Getter implementation to retrieve a value from a dictionary.
@@ -90,18 +90,18 @@ def get(  # type: ignore
             return list(val)
         return [val]
 
-    def keys(  # type: ignore
-        self, carrier: typing.Dict[str, CarrierValT]
+    def keys(
+        self, carrier: typing.Mapping[str, CarrierValT]
     ) -> typing.List[str]:
         """Keys implementation that returns all keys from a dictionary."""
         return list(carrier.keys())
 
 
-default_getter = DefaultGetter()
+default_getter: Getter[CarrierT] = DefaultGetter()  # type: ignore
 
 
-class DefaultSetter(Setter):
-    def set(  # type: ignore
+class DefaultSetter(Setter[typing.MutableMapping[str, CarrierValT]]):
+    def set(
         self,
         carrier: typing.MutableMapping[str, CarrierValT],
         key: str,
@@ -117,7 +117,7 @@ def set(  # type: ignore
         carrier[key] = value
 
 
-default_setter = DefaultSetter()
+default_setter: Setter[CarrierT] = DefaultSetter()  # type: ignore
 
 
 class TextMapPropagator(abc.ABC):
@@ -134,7 +134,7 @@ def extract(
         self,
         carrier: CarrierT,
         context: typing.Optional[Context] = None,
-        getter: Getter = default_getter,
+        getter: Getter[CarrierT] = default_getter,
     ) -> Context:
         """Create a Context from values in the carrier.
 
@@ -162,7 +162,7 @@ def inject(
         self,
         carrier: CarrierT,
         context: typing.Optional[Context] = None,
-        setter: Setter = default_setter,
+        setter: Setter[CarrierT] = default_setter,
     ) -> None:
         """Inject values from a Context into a carrier.
 

opentelemetry-api/src/opentelemetry/trace/propagation/tracecontext.py

@@ -37,7 +37,7 @@ def extract(
         self,
         carrier: textmap.CarrierT,
         context: typing.Optional[Context] = None,
-        getter: textmap.Getter = textmap.default_getter,
+        getter: textmap.Getter[textmap.CarrierT] = textmap.default_getter,
     ) -> Context:
         """Extracts SpanContext from the carrier.
 
@@ -90,7 +90,7 @@ def inject(
         self,
         carrier: textmap.CarrierT,
         context: typing.Optional[Context] = None,
-        setter: textmap.Setter = textmap.default_setter,
+        setter: textmap.Setter[textmap.CarrierT] = textmap.default_setter,
     ) -> None:
         """Injects SpanContext into the carrier.