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NDLRGEN047: Invalid constructor guard enum value

Cause

A [GenerateConstructor] or [ConstructorGuard] argument supplies a ConstructorNullGuardMode or ConstructorGuardKind value that is not one of the enum's defined members -- for example, a value produced by casting an out-of-range integer.

Rule Description

ConstructorGuardKind and ConstructorNullGuardMode arguments must be one of the enum's declared members. Because C# enums are not closed at the type-system level, an expression like (ConstructorGuardKind)99 compiles but has no defined meaning to the generator. Rather than silently falling back to a default guard behavior, this is rejected at compile time so the generated behavior can never silently diverge from what the source appears to request.

How to Fix

Use one of the enum's defined members:

using NexusLabs.Needlr.Generators;

[GenerateConstructor]
public partial class UserService
{
    // WRONG - NDLRGEN047: 99 is not a defined ConstructorGuardKind value
    [ConstructorGuard((ConstructorGuardKind)99)]
    private readonly string _tenantName;
}

// CORRECT - a defined ConstructorGuardKind member
[GenerateConstructor]
public partial class UserService
{
    [ConstructorGuard(ConstructorGuardKind.NotNullOrWhiteSpace)]
    private readonly string _tenantName;
}

See Also