Fix build warnings

src/Tgstation.Server.Host/Authority/Core/AuthorityInvoker{TAuthority}.cs

@@ -85,6 +85,23 @@ namespace Tgstation.Server.Host.Authority.Core
 			return CreateSuccessfulActionResult(controller, result, authorityResponse);
 		}
 
+		/// <inheritdoc />
+		public async ValueTask<TApiModel?> InvokeTransformable<TResult, TApiModel, TTransformer>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
+			where TResult : notnull, IApiTransformable<TResult, TApiModel, TTransformer>
+			where TApiModel : notnull
+			where TTransformer : ITransformer<TResult, TApiModel>, new()
+		{
+			ArgumentNullException.ThrowIfNull(authorityInvoker);
+
+			var authorityResponse = await authorityInvoker(authority);
+			ThrowGraphQLErrorIfNecessary(authorityResponse);
+			var result = authorityResponse.Result;
+			if (result == null)
+				return default;
+
+			return result.ToApi();
+		}
+
 		/// <inheritdoc />
 		async ValueTask IGraphQLAuthorityInvoker<TAuthority>.Invoke(Func<TAuthority, ValueTask<AuthorityResponse>> authorityInvoker)
 		{
@@ -95,7 +112,7 @@ namespace Tgstation.Server.Host.Authority.Core
 		}
 
 		/// <inheritdoc />
-		public async ValueTask<TApiModel> Invoke<TResult, TApiModel>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
+		public async ValueTask<TApiModel?> Invoke<TResult, TApiModel>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
 			where TResult : TApiModel
 			where TApiModel : notnull
 		{
@@ -103,17 +120,7 @@ namespace Tgstation.Server.Host.Authority.Core
 
 			var authorityResponse = await authorityInvoker(authority);
 			ThrowGraphQLErrorIfNecessary(authorityResponse);
-			return authorityResponse.Result!;
-		}
-
-		/// <inheritdoc />
-		async ValueTask<TApiModel> IGraphQLAuthorityInvoker<TAuthority>.InvokeTransformable<TResult, TApiModel, TTransformer>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
-		{
-			ArgumentNullException.ThrowIfNull(authorityInvoker);
-
-			var authorityResponse = await authorityInvoker(authority);
-			ThrowGraphQLErrorIfNecessary(authorityResponse);
-			return authorityResponse.Result!.ToApi();
+			return authorityResponse.Result;
 		}
 
 		/// <inheritdoc />

src/Tgstation.Server.Host/Authority/Core/IGraphQLAuthorityInvoker{TAuthority}.cs

@@ -26,7 +26,7 @@ namespace Tgstation.Server.Host.Authority.Core
 		/// <typeparam name="TApiModel">The resulting <see cref="Type"/> of the return value.</typeparam>
 		/// <param name="authorityInvoker">The <typeparamref name="TAuthority"/> <see cref="Func{T, TResult}"/> returning a <see cref="ValueTask{TResult}"/> resulting in the <see cref="AuthorityResponse{TResult}"/>.</param>
 		/// <returns>A <see cref="ValueTask{TResult}"/> resulting in the <typeparamref name="TApiModel"/> generated for the resulting <see cref="AuthorityResponse{TResult}"/>.</returns>
-		ValueTask<TApiModel> Invoke<TResult, TApiModel>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
+		ValueTask<TApiModel?> Invoke<TResult, TApiModel>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
 			where TResult : TApiModel
 			where TApiModel : notnull;
 
@@ -38,7 +38,7 @@ namespace Tgstation.Server.Host.Authority.Core
 		/// <typeparam name="TTransformer">The <see cref="ITransformer{TInput, TOutput}"/> for converting <typeparamref name="TResult"/>s to <typeparamref name="TApiModel"/>s.</typeparam>
 		/// <param name="authorityInvoker">The <typeparamref name="TAuthority"/> <see cref="Func{T, TResult}"/> returning a <see cref="ValueTask{TResult}"/> resulting in the <see cref="AuthorityResponse{TResult}"/>.</param>
 		/// <returns>A <see cref="ValueTask{TResult}"/> resulting in the <typeparamref name="TApiModel"/> generated for the resulting <see cref="AuthorityResponse{TResult}"/>.</returns>
-		ValueTask<TApiModel> InvokeTransformable<TResult, TApiModel, TTransformer>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
+		ValueTask<TApiModel?> InvokeTransformable<TResult, TApiModel, TTransformer>(Func<TAuthority, ValueTask<AuthorityResponse<TResult>>> authorityInvoker)
 			where TResult : notnull, IApiTransformable<TResult, TApiModel, TTransformer>
 			where TApiModel : notnull
 			where TTransformer : ITransformer<TResult, TApiModel>, new();

src/Tgstation.Server.Host/GraphQL/Types/NodeInformation.cs

@@ -14,6 +14,12 @@ namespace Tgstation.Server.Host.GraphQL.Types
 	[Node]
 	public sealed class NodeInformation
 	{
+		/// <summary>
+		/// Node resolver for <see cref="NodeInformation"/>s.
+		/// </summary>
+		/// <param name="identifier">The <see cref="Identifier"/> to lookup.</param>
+		/// <param name="swarmService">The <see cref="ISwarmService"/> to use.</param>
+		/// <returns>The queried <see cref="NodeInformation"/>, if present.</returns>
 		public NodeInformation? GetNodeInformation(
 			string identifier,
 			[Service] ISwarmService swarmService)

src/Tgstation.Server.Host/GraphQL/Types/User.cs

@@ -51,13 +51,20 @@ namespace Tgstation.Server.Host.GraphQL.Types
 		[GraphQLIgnore]
 		public required long? GroupId { get; init; }
 
-		public static ValueTask<User> GetUser(
+		/// <summary>
+		/// Node resolver for <see cref="User"/>s.
+		/// </summary>
+		/// <param name="id">The <see cref="Entity.Id"/> to lookup.</param>
+		/// <param name="userAuthority">The <see cref="IGraphQLAuthorityInvoker{TAuthority}"/> <see cref="IUserAuthority"/>.</param>
+		/// <param name="cancellationToken">The <see cref="CancellationToken"/> for the operation.</param>
+		/// <returns>A <see cref="ValueTask"/> resulting in the queried <see cref="User"/>, if present.</returns>
+		public static ValueTask<User?> GetUser(
 			long id,
-			[Service] IGraphQLAuthorityInvoker<IUserAuthority> authorityInvoker,
+			[Service] IGraphQLAuthorityInvoker<IUserAuthority> userAuthority,
 			CancellationToken cancellationToken)
 		{
-			ArgumentNullException.ThrowIfNull(authorityInvoker);
-			return authorityInvoker.InvokeTransformable<Models.User, User, UserGraphQLTransformer>(
+			ArgumentNullException.ThrowIfNull(userAuthority);
+			return userAuthority.InvokeTransformable<Models.User, User, UserGraphQLTransformer>(
 				authority => authority.GetId(id, false, false, cancellationToken));
 		}
 
@@ -76,6 +83,9 @@ namespace Tgstation.Server.Host.GraphQL.Types
 				return null;
 
 			var user = await userAuthority.InvokeTransformable<Models.User, User, UserGraphQLTransformer>(authority => authority.GetId(CreatedById.Value, false, true, cancellationToken));
+			if (user == null)
+				return null;
+
 			if (user.CanonicalName == Models.User.CanonicalizeName(Models.User.TgsSystemUserName))
 				return new UserName(user);
 

src/Tgstation.Server.Host/GraphQL/Types/UserName.cs

@@ -19,15 +19,25 @@ namespace Tgstation.Server.Host.GraphQL.Types
 	[Node]
 	public sealed class UserName : NamedEntity, IUserName
 	{
-		public static async ValueTask<UserName> GetUserName(
+		/// <summary>
+		/// Node resolver for <see cref="UserName"/>s.
+		/// </summary>
+		/// <param name="id">The <see cref="Entity.Id"/> to lookup.</param>
+		/// <param name="userAuthority">The <see cref="IGraphQLAuthorityInvoker{TAuthority}"/> <see cref="IUserAuthority"/>.</param>
+		/// <param name="cancellationToken">The <see cref="CancellationToken"/> for the operation.</param>
+		/// <returns>A <see cref="ValueTask"/> resulting in the queried <see cref="UserName"/>, if present.</returns>
+		public static async ValueTask<UserName?> GetUserName(
 			long id,
-			[Service] IGraphQLAuthorityInvoker<IUserAuthority> authorityInvoker,
+			[Service] IGraphQLAuthorityInvoker<IUserAuthority> userAuthority,
 			CancellationToken cancellationToken)
 		{
-			ArgumentNullException.ThrowIfNull(authorityInvoker);
-			var user = await authorityInvoker.InvokeTransformable<Models.User, User, UserGraphQLTransformer>(
+			ArgumentNullException.ThrowIfNull(userAuthority);
+			var user = await userAuthority.InvokeTransformable<Models.User, User, UserGraphQLTransformer>(
 				authority => authority.GetId(id, false, true, cancellationToken));
 
+			if (user == null)
+				return null;
+
 			return new UserName(user);
 		}
 

src/Tgstation.Server.Host/GraphQL/Types/Users.cs

@@ -34,7 +34,7 @@ namespace Tgstation.Server.Host.GraphQL.Types
 			CancellationToken cancellationToken)
 		{
 			ArgumentNullException.ThrowIfNull(userAuthority);
-			return userAuthority.InvokeTransformable<Models.User, User, UserGraphQLTransformer>(authority => authority.Read(cancellationToken));
+			return userAuthority.InvokeTransformable<Models.User, User, UserGraphQLTransformer>(authority => authority.Read(cancellationToken))!;
 		}
 
 		/// <summary>

src/Tgstation.Server.Host/Models/IApiTransformable{TModel,TApiModel,TTransformer}.cs

@@ -11,6 +11,7 @@ namespace Tgstation.Server.Host.Models
 	/// <typeparam name="TApiModel">The API model <see cref="Type"/>.</typeparam>
 	/// <typeparam name="TTransformer">The <see cref="ITransformer{TModel, TApiModel}"/> <see cref="Type"/>.</typeparam>
 	public interface IApiTransformable<TModel, TApiModel, TTransformer>
+		where TApiModel : notnull
 		where TModel : IApiTransformable<TModel, TApiModel, TTransformer>
 		where TTransformer : ITransformer<TModel, TApiModel>, new()
 	{