Diagnostics¶

The generator emits structured diagnostics with the prefix OE. Errors block code generation; warnings allow generation to proceed.

Errors¶

OE0001 — Must Be Partial¶

Message: The class '{0}' must be declared as partial for OptimizedEnum source generation

Cause: A class that inherits from OptimizedEnum<TEnum, TValue> is missing the partial keyword.

Fix:

// Before
public sealed class OrderStatus : OptimizedEnum<OrderStatus, int> { }

// After
public sealed partial class OrderStatus : OptimizedEnum<OrderStatus, int> { }

OE0004 — No Members Found¶

Message: The class '{0}' has no public static readonly fields of its own type

Cause: The class contains no public static readonly fields of its own type. The generator has nothing to build a lookup table from.

Fix: Add at least one member:

public static readonly OrderStatus Pending = new(1, nameof(Pending));

OE0005 — Duplicate Value¶

Message: The class '{0}' has duplicate value on fields '{1}' and '{2}'

Cause: Two members share the same value. Detected best-effort when constructor arguments are compile-time constants.

Fix: Ensure all values are unique.

OE0006 — Duplicate Name¶

Message: The class '{0}' has a duplicate member name '{1}'

Cause: Two fields have the same name (unusual but possible via shadowing or copy-paste).

Fix: Rename one of the fields.

Warnings¶

OE0101 — Non-Private Constructor¶

Message: The class '{0}' has a non-private constructor; OptimizedEnum constructors should be private to prevent direct instantiation

Cause: A constructor has non-private accessibility.

Recommendation: Make the constructor private. Generation still proceeds.

OE0102 — Non-Readonly Field¶

Message: The field '{0}' in class '{1}' is a public static field of the enum type but is not readonly

Cause: A public static field of the enum type is missing readonly. The field is excluded from the generated lookup tables.

Fix: Add readonly to the field declaration.

Suppressing Warnings¶

Warnings can be suppressed via standard MSBuild mechanisms:

<!-- In your .csproj -->
<PropertyGroup>
  <NoWarn>$(NoWarn);OE0101</NoWarn>
</PropertyGroup>

Or inline:

#pragma warning disable OE0101
public OrderStatus(int value, string name) : base(value, name) { }
#pragma warning restore OE0101

SystemTextJson Diagnostics¶

The LayeredCraft.OptimizedEnums.SystemTextJson generator emits diagnostics with the OE2xxx prefix.

OE2001 — Not an OptimizedEnum¶

Message: The class '{0}' must inherit from OptimizedEnum<TEnum, TValue> to use [OptimizedEnumJsonConverter]

Cause: [OptimizedEnumJsonConverter] was applied to a class that does not inherit from OptimizedEnum<TEnum, TValue>.

Fix: Remove the attribute, or make the class inherit from OptimizedEnum<TEnum, TValue>.

OE2002 — Must Be Partial¶

Message: The class '{0}' must be declared as partial for [OptimizedEnumJsonConverter] source generation

Cause: A class decorated with [OptimizedEnumJsonConverter] is missing the partial keyword. The generator cannot stamp the [JsonConverter] attribute onto the class.

Fix:

// Before
[OptimizedEnumJsonConverter(OptimizedEnumJsonConverterType.ByName)]
public sealed class OrderStatus : OptimizedEnum<OrderStatus, int> { ... }

// After
[OptimizedEnumJsonConverter(OptimizedEnumJsonConverterType.ByName)]
public sealed partial class OrderStatus : OptimizedEnum<OrderStatus, int> { ... }

OE2003 — Unknown Converter Type¶

Message: The class '{0}' specifies an unknown OptimizedEnumJsonConverterType value '{1}'; valid values are ByName (0) and ByValue (1)

Cause: An explicit integer cast was used to pass an undefined OptimizedEnumJsonConverterType value to [OptimizedEnumJsonConverter].

Fix: Use only the defined enum members:

[OptimizedEnumJsonConverter(OptimizedEnumJsonConverterType.ByName)]   // or ByValue
public sealed partial class OrderStatus : OptimizedEnum<OrderStatus, int> { ... }

Generator Not Running?¶

If you add the package but see no generated members, check:

Is the class partial? — OE0001 will be emitted and generation stops.
Does it inherit from OptimizedEnum<TEnum, TValue>? — The generator only fires when the base type is found.
Are there any members? — OE0004 fires if no qualifying fields are found.
Check the build output — run dotnet build and look for any OE* diagnostics.
Inspect obj/ generated files — if a .g.cs file exists but the methods aren't available, check for a build cache issue.