Allow lazy function invocation to target version/alias (#679)

* Allow lazy function invocation to target version/alias
* Updating test to properly mock function ARN

Author: angrychimp

slack_bolt/adapter/aws_lambda/handler.py

@@ -56,6 +56,7 @@ def handle(self, event, context):
             # https://docs.aws.amazon.com/lambda/latest/dg/python-context.html
             aws_lambda_function_name = context.function_name
             bolt_req.context["aws_lambda_function_name"] = aws_lambda_function_name
+            bolt_req.context["aws_lambda_invoked_function_arn"] = context.invoked_function_arn
             bolt_req.context["lambda_request"] = event
             bolt_resp = self.app.dispatch(bolt_req)
             aws_response = to_aws_response(bolt_resp)

slack_bolt/adapter/aws_lambda/lazy_listener_runner.py

@@ -23,7 +23,7 @@ def start(self, function: Callable[..., None], request: BoltRequest) -> None:
         headers["x-slack-bolt-lazy-function-name"] = request.lazy_function_name  # not an array
         event["method"] = "NONE"
         invocation = self.lambda_client.invoke(
-            FunctionName=request.context["aws_lambda_function_name"],
+            FunctionName=request.context["aws_lambda_invoked_function_arn"],
             InvocationType="Event",
             Payload=json.dumps(event),
         )

tests/adapter_tests/aws/test_aws_lambda.py

@@ -25,6 +25,7 @@ class LambdaContext:
 
     def __init__(self, function_name: str):
         self.function_name = function_name
+        self.invoked_function_arn = f'arn:aws:lambda:us-east-1:account-id:function:{self.function_name}'
 
 
 class TestAWSLambda: