| """ |
| Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. |
| SPDX-License-Identifier: MIT-0 |
| """ |
|
|
| from typing import Any |
|
|
| import regex as re |
|
|
| from cfnlint.helpers import REGEX_SUB_PARAMETERS, ensure_list |
| from cfnlint.jsonschema import ValidationError, ValidationResult, Validator |
| from cfnlint.rules import CloudFormationLintRule |
|
|
|
|
| class SubUnneeded(CloudFormationLintRule): |
| """Check if Sub is using a variable""" |
|
|
| id = "W1020" |
| shortdesc = "Sub isn't needed if it doesn't have a variable defined" |
| description = "Checks sub strings to see if a variable is defined." |
| source_url = "https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-sub.html" |
| tags = ["functions", "sub"] |
|
|
| def validate( |
| self, validator: Validator, s: Any, instance: Any, schema: Any |
| ) -> ValidationResult: |
| if "AWS::Serverless-2016-10-31" in ensure_list( |
| validator.cfn.transform_pre.get("Transform") |
| ): |
| return |
| if validator.is_type(instance, "string"): |
| variables = re.findall(REGEX_SUB_PARAMETERS, instance) |
| path = [] |
| else: |
| variables = re.findall(REGEX_SUB_PARAMETERS, instance[0]) |
| path = [0] |
| if not variables: |
| yield ValidationError( |
| "'Fn::Sub' isn't needed because there are no variables", path=path |
| ) |
|
|
