Python synthesizer generates empty `if` blocks for conditional resources

[sai-ray]

When a conditional resource has no metadata, update_policy, deletion_policy, or dependencies, the Python synthesizer generates an empty if block which is a syntax error.

It should either emit pass or skip the if block entirely when there are no attributes to emit.

Can be reproduced by any CloudFormation template with a conditional resource that has no Metadata, UpdatePolicy, DeletionPolicy, or DependsOn.

For example:

Input

AWSTemplateFormatVersion: "2010-09-09"
Conditions:
  CreateResource:
    !Equals [!Ref "AWS::Region", "us-east-1"]
Resources:
  ConditionalBucket:
    Type: AWS::S3::Bucket
    Condition: CreateResource
    Properties:
      BucketName: test-bucket'

Output

from aws_cdk import Stack
import aws_cdk as cdk
import aws_cdk.aws_s3 as s3
from constructs import Construct

class NoctStack(Stack):
  def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
    super().__init__(scope, construct_id, **kwargs)

    # Conditions
    create_resource = self.region == 'us-east-1'

    # Resources
    conditionalBucket = s3.CfnBucket(self, 'ConditionalBucket',
          bucket_name = 'test-bucket',
        ) if create_resource else None
    if (conditionalBucket is not None):

The file ends with if (conditionalBucket is not None):. Nothing after the if statement. Python requires at least pass inside an if block, otherwise it's a syntax error.