Production-Ready Example Integrations

PatternKit examples are meant to be importable building blocks, not throwaway snippets. The examples package now exposes a production-readiness catalog that applications, tests, documentation tooling, and ASP.NET Core diagnostics can use to discover which examples exist, where their source/tests/docs live, and which integration surfaces they exercise.

Register the catalog

Use the standard .NET dependency injection container:

using Microsoft.Extensions.DependencyInjection;
using PatternKit.Examples.ProductionReadiness;

var services = new ServiceCollection()
    .AddLogging()
    .AddPatternKitExampleCatalog()
    .AddPatternKitPatternCatalog();

using var provider = services.BuildServiceProvider(validateScopes: true);
var catalog = provider.GetRequiredService<IPatternKitExampleCatalog>();
var patterns = provider.GetRequiredService<IPatternKitPatternCatalog>();

Register runnable examples

The examples package also exposes a fluent IoC surface for every catalog entry. Existing applications can import the complete example suite with one call:

using Microsoft.Extensions.DependencyInjection;
using PatternKit.Examples.DependencyInjection;
using PatternKit.Examples.ProductionReadiness;

var services = new ServiceCollection()
    .AddLogging()
    .AddPatternKitExamples();

using var provider = services.BuildServiceProvider(validateScopes: true);

var pricing = provider.GetRequiredService<PricingCalculatorExample>();
var catalog = provider.GetRequiredService<IPatternKitExampleCatalog>();
var patterns = provider.GetRequiredService<IPatternKitPatternCatalog>();

Each example also has its own focused extension, so sample applications can import only the slice they need:

services
    .AddPricingCalculatorExample()
    .AddPaymentProcessorDecoratorExample()
    .AddMessagingBackplaneFacadeExample();

Every extension registers a concrete typed entry point, such as PricingCalculatorExample, EnterpriseFeatureSlicesExample, MinimalWebRequestRouterExample, or ReactiveTransactionExample. The companion PatternKitExampleServiceDescriptor registrations make the IoC surface auditable: tests compare those descriptors against the production-readiness catalog and resolve every registered example through IServiceProvider.

Each PatternKitExampleDescriptor includes:

Field	Purpose
Name	Human-readable example name.
SourcePath	Repository source file or entry point.
TestPath	TinyBDD scenario coverage for the example.
DocumentationPath	DocFX page for the example.
Integration	Tooling surfaces covered: DI, options, generic host, ASP.NET Core, source generators, messaging, or external infrastructure.
Patterns	PatternKit primitives demonstrated by the example.
ProductionChecks	The behaviors that make the example production-shaped and regression-testable.

The companion IPatternKitPatternCatalog records the broader pattern matrix: GoF patterns, enterprise integration patterns, messaging reliability patterns, and application architecture patterns. It links each pattern to its fluent/runtime path, TinyBDD tests, real-world example, and source-generated path. Any missing generated path must point to a tracked issue so planned work stays visible.

Validate in a generic host

Applications can fail fast during startup when catalog metadata is malformed or when source/docs/tests are missing from a repository checkout:

using Microsoft.Extensions.Hosting;
using PatternKit.Examples.ProductionReadiness;

var builder = Host.CreateApplicationBuilder(args);

builder.AddPatternKitExampleHostedValidation(options =>
{
    options.RepositoryRoot = "/work/PatternKit";
    options.FailOnInvalid = true;
});

using var host = builder.Build();
await host.StartAsync();

When RepositoryRoot is unset, validation still checks descriptor quality: names, paths, integration surfaces, listed patterns, and production checks. Supplying a repository root also verifies that the referenced source, test, and documentation files exist.

Expose diagnostics in ASP.NET Core

ASP.NET Core apps can map a tiny diagnostics endpoint for internal documentation portals or build verification:

using PatternKit.Examples.ProductionReadiness;

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddPatternKitExampleCatalog();

var app = builder.Build();
app.MapPatternKitExampleCatalog();

await app.RunAsync();

This maps:

Route	Result
/patternkit/examples	The catalog descriptors.
/patternkit/examples/validation	A validation report, with HTTP 500 when validation fails.

Readiness Contract

Every documented example should satisfy the same baseline contract:

Requirement	How it is enforced
Documented in DocFX	docs/examples/toc.yml links to the page and documentation tests validate hrefs.
Covered by TinyBDD scenarios	The catalog points to a test file and catalog tests verify it exists.
Importable from the examples package	The catalog is part of PatternKit.Examples and is registered through IServiceCollection/IHostApplicationBuilder.
Has an IoC entry point	AddPatternKitExamples() and per-example Add...Example() extensions register typed example services through IServiceCollection.
Host/tooling friendly where applicable	Integration flags identify examples that demonstrate IOptions, DI, generic host, ASP.NET Core, source generators, messaging, or external infrastructure.
Production-shaped behavior called out	ProductionChecks records the behaviors each example must keep validating.

Current Catalog Scope

The catalog covers every page in the examples ToC, including:

Area	Examples
Request and pipeline composition	Auth/logging chain, minimal web router, mediated transaction pipeline, configuration-driven pipeline.
Host and DI composition	Enterprise feature slices, source-generator application suite, messaging backplane facade.
Messaging	Enterprise messaging workflow suite, resilient checkout, collaborating mailboxes, message router visitor.
POS and pricing	Payment processor decorator, pricing calculator, POS app state, tender visitor.
Behavioral workflows	Async state machine, reactive ViewModel, reactive transaction, template method sync/async, event processing visitor.
Structural and creational patterns	Flyweight glyph cache, proxy demos, prototype registry, text editor memento, observer hub.

The catalog is intentionally small and static. It is easy to audit in code review, cheap to resolve at runtime, and suitable for use in build checks, docs portals, sample applications, or internal architecture dashboards.