testbed/aws-cloudformation__cfn-lint/src/cfnlint/rules/functions/Length.py

"""
Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
SPDX-License-Identifier: MIT-0
"""

from __future__ import annotations

from typing import Any

from cfnlint.jsonschema import ValidationError, ValidationResult, Validator
from cfnlint.rules.functions._BaseFn import BaseFn, all_types


class Length(BaseFn):
    """Check if Length values are correct"""

    id = "E1030"
    shortdesc = "Length validation of parameters"
    description = "Making sure Fn::Length is configured correctly"
    source_url = "https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-length.html"
    tags = ["functions", "length"]

    def __init__(self) -> None:
        super().__init__(
            "Fn::Length",
            ("integer",),
            (
                "Ref",
                "Fn::FindInMap",
                "Fn::Split",
                "Fn::If",
                "Fn::GetAZs",
            ),
        )

    def schema(self, validator: Validator, instance: Any) -> dict[str, Any]:
        return {
            "type": ["array"],
            "fn_items": {
                "functions": [
                    "Fn::If",
                    "Fn::Base64",
                    "Fn::FindInMap",
                    "Fn::Join",
                    "Fn::Select",
                    "Fn::Split",
                    "Fn::Sub",
                    "Fn::ToJsonString",
                    "Fn::GetAZs",
                    "Ref",
                ],
                "schema": {
                    "type": all_types,
                },
            },
        }

    def fn_length(
        self, validator: Validator, s: Any, instance: Any, schema: Any
    ) -> ValidationResult:
        if not validator.context.transforms.has_language_extensions_transform():
            yield ValidationError(
                (
                    f"{self.fn.name} is not supported without "
                    "'AWS::LanguageExtensions' transform"
                ),
                validator=self.fn.py,
                rule=self,
            )
            return

        for err in super().validate(validator, s, instance, schema):
            err.rule = self
            yield err