IoCTools.Abstractions 1.7.3

IoCTools

A Roslyn source generator that lets each service declare its own lifetime, dependencies, and registration intent with small attributes. IoCTools emits constructors, service registrations, and analyzers at build time—no reflection, no runtime scanning.

Highlights

• Self-describing services – [Scoped], [DependsOn<T>], [RegisterAs<…>], and [ConditionalService] live on the class, so intent never leaves the type
• Dependency sets – Implement IDependencySet to reuse dependency bundles across services
• Inheritance-aware – Derived services inherit base class lifetime; diagnostics validate across the full chain
• 100+ diagnostics – Build-time validation catches missing lifetimes, circular dependencies, lifetime mismatches, open-generic edge cases, and FluentValidation anti-patterns
• Zero reflection – Everything happens at compile time; generated code is plain C# you can inspect

Authoring Posture

• [Inject] is deprecated in 1.6.0 and emits IOC095. A Roslyn code fix plus ioc-tools migrate-inject migrate in bulk. Scheduled for removal in 2.0.
• [DependsOn<T>] is the source-of-truth for explicit service dependencies.
• [DependsOnConfiguration<T>] / [DependsOnOptions<T>] for config dependencies. InjectConfiguration stays supported but is not preferred.
• Auto-deps (1.6.0+) declare ambient dependencies once per assembly: [assembly: AutoDep<T>], [assembly: AutoDepOpen(typeof(ILogger<>))], plus Microsoft.Extensions.Logging.ILogger<T> is auto-detected with zero configuration. See docs/auto-deps.md.

Installation

dotnet add package IoCTools.Abstractions
dotnet add package IoCTools.Generator

Or directly in your project file:

<ItemGroup>
  <PackageReference Include="IoCTools.Abstractions" Version="*" />
  <PackageReference Include="IoCTools.Generator" Version="*" PrivateAssets="all" />
</ItemGroup>

What's New in v1.7.3

Fixed in 1.7.3

• IOC997 crash on array TypedConstant args fixed — TestFixtureAnalyzer and AttributeParser now guard against calling .Value on Array-kinded TypedConstants, which occurs when a DependsOn-prefixed attribute is called with multiple typeof() args (e.g. [DependsOnExtras(typeof(IFoo), typeof(IBar))]).
• TDIAG04 false positive for [GeneratedCode("IoCTools")] constructors fixed — HasConstructorGenerationIntent now recognizes constructors tagged by IoCTools in a prior pass, preventing false TDIAG04 on Keel LoggedHandler<T> subclasses.

Fixed in 1.7.2

• [Cover<T>] source compatibility restored — IoCTools.Testing now injects IoCTools.Testing.Annotations as a global using via its MSBuild .targets file. Consumers using PrivateAssets="all" with no explicit using directive no longer receive CS0246 on Cover<>, CoverAttribute<>, or FixtureLoggerProfile.
• IOC997 crash on scalar nameof() args fixed — TestFixtureAnalyzer now correctly handles params string[] attribute arguments stored as scalar TypedConstant by the C# compiler (e.g. [ProjectSignalFrom<T>(nameof(T.Id))]).
• TDIAG08 downgraded to Info — no longer blocks compilation in TreatWarningsAsErrors=true projects. Escalate with <IoCToolsTestingDiagnosticSeverity>Warning</IoCToolsTestingDiagnosticSeverity> for strict mode.

Features introduced in v1.7.x (all in 1.7.2)

v1.7.0 was tagged but never published to NuGet — CI failed in the CLI fixture-evidence build step before the publish job ran. v1.7.1 is the first published release with the 1.7 features, but had consumer regressions fixed in 1.7.2.

• AnalysisScope model + DiagnosticGate — each diagnostic declares whether it fires in production projects, test projects, or both. IOC081/IOC082/IOC086 are reclassified as AnalysisScope.Production; test projects are auto-exempt via the IsTestProject MSBuild property (forwarded as a CompilerVisibleProperty from Microsoft.NET.Test.Sdk). No naming heuristics.
• IOC110 (Warning, configurable via IoCToolsLifetimeValidationSeverity) — deterministic multi-impl lifetime diagnostic. Fires when some (not all) implementations of an interface violate the lifetime dependency rule. Replaces the previous non-deterministic single-impl selection that caused IOC012 to fire in Rider but pass silently in CLI.
• IOC073 / IOC066 — open-generic and inaccessible IHostedService implementers are skipped at registration with observable diagnostics (rather than emitting CS0246/CS0122 in consumer code).
• [RegisterAs<T>] + [RegisterAsAll] compose with IHostedService — the concrete class is registered once at the declared lifetime, companion interfaces bridged via GetRequiredService<TImpl>(), and IHostedService bridged to the same instance.
• Test fixture generator v2 (IoCTools.Testing) — FixtureMemberPlanner separates planning from emission. Generated fixtures enable nullable context, emit new modifier on derived hidden members, support GetRequiredSection and binder-style configuration reads, and treat IClock as fixture-provided.
• IOC032 InstanceSharing.Shared exemption, IOC081/082/086 carve-outs for Replace, factory lambdas, TryAddEnumerable, and IoCTools-unaware assemblies, buildTransitive packaging of IoCTools.Generator.targets, and CLI host-path resolver that walks PATH before throwing.
• Multitarget CLI — IoCTools.Tools.Cli ships for both net9.0 and net10.0. Existing .NET 9 global-tool consumers are not broken.
• CI build fix (1.7.1) — removed accidental IoCTools.Testing analyzer reference from FixtureEvidence.TestsProject (CLI evidence corpus only needs IoCTools.Testing.Abstractions for [Cover<T>]); removed unused ProductionPreferenceHelperTests helper that combined IoCTools deps with a manual constructor, triggering IOC041 through diagnostics core (net9.0 builds pass; net8.0 CI now installs SDK 8.0.x).

Getting Started in Three Steps

1. Annotate a partial service

   [DependsOn<ILogger<EmailService>>]
   public partial class EmailService : IEmailService
   {
       public Task SendAsync(string to, string subject, string body) => Task.CompletedTask;
   }
   

   Tip: [Scoped] is implied for partial classes implementing interfaces. Add [Singleton]/[Transient] only when you want to change that default.

   Full getting started guide

2. Build – IoCTools emits Add<YourAssembly>RegisteredServices() into <AssemblyName>.Extensions.Generated.

3. Call the extension during startup

   using YourAssembly.Extensions.Generated;
   
   var builder = WebApplication.CreateBuilder(args);
   builder.Services.AddYourAssemblyRegisteredServices(builder.Configuration);
   

Common Open-Generic Pattern

[Scoped]
[RegisterAsAll]
public partial class Repository<T> : IRepository<T> where T : class
{
}

That common open-generic path is supported. If you ask for InstanceSharing.Shared across open-generic interface aliases, IoCTools emits the secondary IOC095 descriptor and falls back to valid direct registrations because Microsoft.Extensions.DependencyInjection does not support open-generic factory aliases. (In 1.6.0+, the primary IOC095 descriptor is the [Inject] deprecation diagnostic — both ship under the same ID; see diagnostics.md.)

Platform Support

IoCTools works with .NET Framework 4.6.1+, .NET Core 2.0+, and .NET 5+. The generator targets netstandard2.0 internally, but your service code can use any C# features your framework supports. See platform constraints for details.

Testing with IoCTools

The IoCTools.Testing package auto-generates test fixtures, eliminating mock declaration boilerplate.

using IoCTools.Testing.Annotations;

[Cover<UserService>]
public partial class UserServiceTests
{
    [Fact]
    public void Test() {
        var result = Sut.GetById(1); // Lazy auto-generated SUT
    }
}

Full testing guide

The CLI includes test scaffold and fixture-aware evidence --test-fixtures paths for downstream adoption:

dotnet ioc-tools test scaffold --project src/App.csproj --type MyApp.Services.UserService --dry-run
dotnet ioc-tools evidence --project tests/App.Tests.csproj --production-project src/App.csproj --test-fixtures

IoCTools CLI

IoCTools.Tools.Cli ships as a dotnet global/local tool (dotnet ioc-tools …). It interrogates your project with the real IoCTools generator.

Installation

dotnet pack IoCTools.Tools.Cli/IoCTools.Tools.Cli.csproj -c Release -o ./artifacts
dotnet tool install --global --add-source ./artifacts IoCTools.Tools.Cli

Commands

Full CLI reference

Before & After: Replacing DI Smells

Legacy (manual, brittle)

public class LegacyBillingService : IBillingService
{
    private readonly ILogger<LegacyBillingService> _logger;
    private readonly IHttpClientFactory _httpClients;
    private readonly BillingOptions _options;
    private readonly IConfiguration _config;

    public LegacyBillingService(
        ILogger<LegacyBillingService> logger,
        IHttpClientFactory httpClients,
        IOptionsMonitor<BillingOptions> options,
        IConfiguration config)
    {
        _logger = logger;
        _httpClients = httpClients;
        _options = options.CurrentValue;
        _config = config;
    }
}

services.AddHttpClient();
services.Configure<BillingOptions>(configuration.GetSection("Billing"));
services.AddScoped<IBillingService, LegacyBillingService>();

Problems: duplicated registrations, runtime config lookups, no analyzer guardrails.

IoCTools (attributes, analyzers, generated DI)

using IoCTools.Abstractions.Annotations;

[Scoped]
[DependsOn<ILogger<BillingService>, IHttpClientFactory, IClock>]
[DependsOnConfiguration<string>("Billing:BaseUrl", Required = true)]
[DependsOnConfiguration<int>("Billing:RetryCount", DefaultValue = "3")]
public partial class BillingService : IBillingService
{
    public async Task ChargeAsync(BillingRequest request)
    {
        using var client = _httpClientFactory.CreateClient("billing");
        // _logger, _httpClientFactory, _clock, _baseUrl, _retryCount all available
    }
}

Generated code creates the constructor, binds configuration, and registers everything via builder.Services.AddYourAssemblyRegisteredServices(configuration).

Attribute Reference

Complete attribute reference: docs/attributes.md

Key attributes: [Scoped], [Singleton], [Transient], [DependsOn<T>], [DependsOnConfiguration<T>], [DependsOnOptions<T>], [RegisterAs<T>], [ConditionalService], and the 1.6.0 auto-deps surface ([assembly: AutoDep<T>], [assembly: AutoDepOpen(...)], [AutoDeps<TProfile>], [NoAutoDeps], …)

Diagnostics Reference

IoCTools provides core diagnostics through IOC110, plus testing diagnostics (TDIAG01 through TDIAG08) and FluentValidation diagnostics (IOC100-IOC102). See diagnostics.md for the full list.

Error-Severity Diagnostics

View all diagnostics including warnings and info

Configuration

IoCTools reads configuration from MSBuild properties/.editorconfig. Common knobs:

See configuration reference

Samples & License

• IoCTools.Sample demonstrates every attribute, diagnostic, and configuration scenario
• Licensed under MIT. See LICENSE