type hint

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

@@ -12,11 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import typing
+
 from .base_context import BaseRuntimeContext
 
 __all__ = ['Context']
 
-Context: BaseRuntimeContext = None
+Context: typing.Union[BaseRuntimeContext, None] = None
 
 try:
     from .async_context import AsyncRuntimeContext

opentelemetry-api/src/opentelemetry/context/async_context.py

@@ -12,29 +12,30 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import contextvars
+from contextvars import ContextVar
+import typing
 
 from .base_context import BaseRuntimeContext
 
 
 class AsyncRuntimeContext(BaseRuntimeContext):
     class Slot(BaseRuntimeContext.Slot):
-        def __init__(self, name, default):
+        def __init__(self, name: str, default: typing.Any):
             # pylint: disable=super-init-not-called
             self.name = name
-            self.contextvar = contextvars.ContextVar(name)
+            self.contextvar: typing.Any = ContextVar(name)
             self.default = default if callable(default) else (lambda: default)
 
-        def clear(self):
+        def clear(self) -> None:
             self.contextvar.set(self.default())
 
-        def get(self):
+        def get(self) -> typing.Any:
             try:
                 return self.contextvar.get()
             except LookupError:
                 value = self.default()
                 self.set(value)
                 return value
 
-        def set(self, value):
+        def set(self, value: typing.Any) -> None:
             self.contextvar.set(value)

opentelemetry-api/src/opentelemetry/context/base_context.py

@@ -60,7 +60,7 @@ def register_slot(cls, name: str, default: typing.Any = None) -> 'Slot':
             cls._slots[name] = slot
             return slot
 
-    def apply(self, snapshot) -> None:
+    def apply(self, snapshot: typing.Dict[str, typing.Any]) -> None:
         """Set the current context from a given snapshot dictionary"""
 
         for name in snapshot:
@@ -75,24 +75,31 @@ def snapshot(self) -> typing.Dict[str, typing.Any]:
     def __repr__(self) -> str:
         return '{}({})'.format(type(self).__name__, self.snapshot())
 
-    def __getattr__(self, name) -> typing.Any:
+    def __getattr__(self, name: str) -> typing.Any:
         if name not in self._slots:
             self.register_slot(name, None)
         slot = self._slots[name]
         return slot.get()
 
-    def __setattr__(self, name, value) -> None:
+    def __setattr__(self, name: str, value: typing.Any) -> None:
         if name not in self._slots:
             self.register_slot(name, None)
         slot = self._slots[name]
         slot.set(value)
 
-    def with_current_context(self, func: typing.Callable) -> typing.Callable:
-        """Capture the current context and apply it to the provided func"""
+    def with_current_context(
+            self,
+            func: typing.Callable[..., typing.Any],
+        ) -> typing.Callable[..., typing.Any]:
+        """Capture the current context and apply it to the provided func.
+        """
 
         caller_context = self.snapshot()
 
-        def call_with_current_context(*args, **kwargs) -> typing.Any:
+        def call_with_current_context(
+                *args: typing.Any,
+                **kwargs: typing.Any,
+            ) -> typing.Any:
             try:
                 backup_context = self.snapshot()
                 self.apply(caller_context)

opentelemetry-api/src/opentelemetry/context/thread_local_context.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import threading
+import typing
 
 from .base_context import BaseRuntimeContext
 
@@ -21,21 +22,21 @@ class ThreadLocalRuntimeContext(BaseRuntimeContext):
     class Slot(BaseRuntimeContext.Slot):
         _thread_local = threading.local()
 
-        def __init__(self, name, default):
+        def __init__(self, name: str, default: typing.Any):
             # pylint: disable=super-init-not-called
             self.name = name
             self.default = default if callable(default) else (lambda: default)
 
-        def clear(self):
+        def clear(self) -> None:
             setattr(self._thread_local, self.name, self.default())
 
-        def get(self):
+        def get(self) -> typing.Any:
             try:
                 return getattr(self._thread_local, self.name)
             except AttributeError:
                 value = self.default()
                 self.set(value)
                 return value
 
-        def set(self, value):
+        def set(self, value: typing.Any) -> None:
             setattr(self._thread_local, self.name, value)