EnumCase.rawValue returns "-" for negative enum rawValues

[S-V]

Hi,
we've noticed a regression in Sourcery 1.6.0 when dealing with negative raw enum values.
It's a legacy project that was previously using Sourcery 1.2.1.

What version of Swift are you using (swift --version)?

Apple Swift version 5.5.1 (swiftlang-1300.0.31.4 clang-1300.0.29.6)

What did you do?

My template (simplified from https://github.com/eugeneego/legacy/blob/master/Sources/Templates/Transformer.swifttemplate):

<%_

func enumRawValue(for enumCase: EnumCase) -> String {
    return enumCase.rawValue ?? "\"\(enumCase.name)\""
}
-%>

<%
for enumType in types.enums {
-%>

// swiftlint:disable all
struct TestTransformer {
    typealias Source = Any
    typealias Destination = Test

    func transform(source value: Source) -> TransformerResult<Destination> {
        guard let rawValue = transformer.transform(source: value).value else { return .failure(.transform) }

        switch rawValue {
            <%_ for enumCase in enumType.cases { -%>
            case <%= enumRawValue(for: enumCase) %>:
                return .success(.<%= enumCase.name %>)
            <%_ } -%>
            default:
                return defaultCaseHandler();
        }
    }

    func transform(destination value: Destination) -> TransformerResult<Source> {
        switch value {
            <%_ for enumCase in enumType.cases { -%>
            case .<%= enumCase.name %>:
                return transformer.transform(destination: <%= enumRawValue(for: enumCase) %>)
            <%_ } -%>
        }
    }
}

<%
}
-%>

My enum:

// sourcery: transformer
struct TestStruct {
    var state: StateType

    // sourcery: enumTransformer
    enum StateType: Int {
        // sourcery: defaultCase
        case unsupported = -1
        case success = 0
        case failure = 1
        case cancelled = 2
    }
}

What did you expect to see?

// swiftlint:disable all
struct TestTransformer {
    typealias Source = Any
    typealias Destination = Test

    func transform(source value: Source) -> TransformerResult<Destination> {
        guard let rawValue = transformer.transform(source: value).value else { return .failure(.transform) }

        switch rawValue {
            case -1:
                return .success(.unsupported)
            case 0:
                return .success(.success)
            case 1:
                return .success(.failure)
            case 2:
                return .success(.cancelled)
            default:
                return defaultCaseHandler();
        }
    }

    func transform(destination value: Destination) -> TransformerResult<Source> {
        switch value {
            case .unsupported:
                return transformer.transform(destination: -1)
            case .success:
                return transformer.transform(destination: 0)
            case .failure:
                return transformer.transform(destination: 1)
            case .cancelled:
                return transformer.transform(destination: 2)
        }
    }
}

What did you see instead?

Notice "case -" and "(destination: -)" - these do not compile and we have to correct them manually.

// swiftlint:disable all
struct TestTransformer {
    typealias Source = Any
    typealias Destination = Test

    func transform(source value: Source) -> TransformerResult<Destination> {
        guard let rawValue = transformer.transform(source: value).value else { return .failure(.transform) }

        switch rawValue {
            case -:
                return .success(.unsupported)
            case 0:
                return .success(.success)
            case 1:
                return .success(.failure)
            case 2:
                return .success(.cancelled)
            default:
                return defaultCaseHandler();
        }
    }

    func transform(destination value: Destination) -> TransformerResult<Source> {
        switch value {
            case .unsupported:
                return transformer.transform(destination: -)
            case .success:
                return transformer.transform(destination: 0)
            case .failure:
                return transformer.transform(destination: 1)
            case .cancelled:
                return transformer.transform(destination: 2)
        }
    }
}