""" Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. SPDX-License-Identifier: MIT-0 """ import json from cfnlint.jsonschema import ValidationError from cfnlint.rules import CloudFormationLintRule class EqualsIsUseful(CloudFormationLintRule): """ Validate that the Equals will return true/false and not always be true or false """ id = "W8003" shortdesc = "Fn::Equals will always return true or false" description = ( "Validate Fn::Equals to see if its comparing two strings or two equal items." " While this works it may not be intended." ) source_url = "https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-conditions.html#intrinsic-function-reference-conditions-equals" tags = ["functions", "equals"] def equals_is_useful(self, validator, s, instance, schema): if not validator.is_type(instance, "array"): return if len(instance) != 2: return # testing on 2023/09/24 # True (boolean) != "True" # True (boolean) == "true" # 1 == "1" if json.dumps(instance[0]) == json.dumps(instance[1]): yield ValidationError( f"{instance!r} will always return {True!r} or {False!r}", rule=self, ) return try: first = instance[0] second = instance[1] if validator.is_type(first, "boolean"): first = "true" if first else "false" if validator.is_type(second, "boolean"): first = "true" if first else "false" if str(first) == str(second): yield ValidationError( f"{instance!r} will always return {True!r} or {False!r}", rule=self, ) except: # noqa: E722 pass