TRLS022 — Wrong [StringLength] or [Range] attribute namespace

• Severity: Warning
• Category: Trellis

What it detects

Flags System.ComponentModel.DataAnnotations.StringLengthAttribute and RangeAttribute when they are applied to Trellis value-object base types.

Why it matters

The code compiles, but the Trellis source generator only understands the Trellis versions of these attributes. Your intended validation rules never make it into the generated type.

Warning

This is a namespace problem, not a syntax problem. The attribute name looks right, but the generator ignores the DataAnnotations version.

Bad example

using Trellis;

[System.ComponentModel.DataAnnotations.StringLength(50)]
public sealed partial class FirstName : RequiredString<FirstName>
{
}

Good example

using Trellis;

[StringLength(50)]
public sealed partial class FirstName : RequiredString<FirstName>
{
}

Code fix available

No.

Configuration

Use standard Roslyn configuration if you need to suppress this rule in a specific scope.

dotnet_diagnostic.TRLS022.severity = none

#pragma warning disable TRLS022
// Intentional: documented exception or test-only pattern.
#pragma warning restore TRLS022

Tip

Import or fully qualify Trellis.StringLength and Trellis.Range on Trellis value objects.