def _get_from_sub()

in cfn-lint-serverless/cfn_lint_serverless/utils.py [0:0]

• 16 lines of code
• 6 McCabe index (conditional complexity)

    def _get_from_sub(self, value: Union[str, list]) -> Tuple[str, List[str]]:
        """
        Return the name and references from a 'Fn::Sub' intrinsic function
        """

        pattern = value
        variables = {}

        if isinstance(value, list):
            pattern = value[0]
            # Using Value() here to get nested references
            variables = {k: Value(v) for k, v in value[1].items()}

        references = []

        for match in SUB_PATTERN.findall(pattern):
            if match in variables:
                # Variable with reference(s)
                if len(variables[match].references) > 0:
                    references.extend(variables[match].references)
                # Hard-coded variable
                else:
                    # Replace with hard-coded value in value ID
                    pattern = pattern.replace(f"${{{match}}}", variables[match].id)
            # No matching variable
            else:
                references.append(match)

        return (pattern, references)