Add CI-backed verification for C# Fundamentals examples

.github/workflows/build.yml

@@ -0,0 +1,46 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - main
+      - "feature/**"
+  pull_request:
+    branches:
+      - main
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+env:
+  SOLUTION_PATH: src/CSharpFundamentals/CSharpFundamentals.slnx
+
+jobs:
+  build:
+    name: Build (.NET 10)
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v6
+
+      - name: Set up .NET 10
+        uses: actions/setup-dotnet@v5
+        with:
+          dotnet-version: 10.0.x
+
+      - name: Restore dependencies
+        run: dotnet restore "$SOLUTION_PATH"
+
+      - name: Build in Release mode
+        run: dotnet build "$SOLUTION_PATH" --configuration Release --no-restore --warnaserror
+
+      - name: Verify executable examples
+        run: >-
+          dotnet run
+          --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamentals.csproj
+          --configuration Release
+          --no-build
+          --
+          verify

.github/workflows/markdown-links.yml

@@ -0,0 +1,39 @@
+name: Markdown Links
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - "**/*.md"
+      - ".github/workflows/markdown-links.yml"
+  pull_request:
+    branches:
+      - main
+    paths:
+      - "**/*.md"
+      - ".github/workflows/markdown-links.yml"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  links:
+    name: Validate Markdown links
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v6
+
+      - name: Check links
+        uses: lycheeverse/lychee-action@v2.8.0
+        with:
+          args: >-
+            --root-dir "${{ github.workspace }}"
+            --verbose
+            --no-progress
+            "./**/*.md"
+          fail: true
+          jobSummary: true

README.md

@@ -1,10 +1,12 @@
 <div align="center">
   <img src="./assets/csharp-fundamentals-banner.svg" alt="C# engineering reference" width="100%" />
 
+  [![Build](https://github.com/Sahithbasani/csharp-fundamentals/actions/workflows/build.yml/badge.svg)](https://github.com/Sahithbasani/csharp-fundamentals/actions/workflows/build.yml)
+  [![Markdown Links](https://github.com/Sahithbasani/csharp-fundamentals/actions/workflows/markdown-links.yml/badge.svg)](https://github.com/Sahithbasani/csharp-fundamentals/actions/workflows/markdown-links.yml)
   [![C#](https://img.shields.io/badge/C%23-engineering-512BD4?logo=csharp&logoColor=white)](https://learn.microsoft.com/dotnet/csharp/)
   [![.NET](https://img.shields.io/badge/.NET-10-512BD4?logo=dotnet&logoColor=white)](https://dotnet.microsoft.com/)
   [![Modules](https://img.shields.io/badge/modules-10-0F766E)](#module-index)
-  [![License](https://img.shields.io/badge/license-MIT-2563EB)](./LICENSE)
+  [![License](https://img.shields.io/github/license/Sahithbasani/csharp-fundamentals?color=2563EB)](./LICENSE)
 </div>
 
 # C# Engineering Fundamentals
@@ -16,10 +18,12 @@ This repository is not organized as a syntax tutorial. Each module is an enginee
 ## Table of Contents
 
 - [Engineering Model](#engineering-model)
+- [Engineering Quality](#engineering-quality)
 - [Module Index](#module-index)
 - [Documentation Standard](#documentation-standard)
 - [Runnable Scenarios](#runnable-scenarios)
 - [Build and Validate](#build-and-validate)
+- [Technical Blog Watch](#technical-blog-watch)
 - [Repository Structure](#repository-structure)
 - [Contribution Standard](#contribution-standard)
 
@@ -34,6 +38,16 @@ flowchart LR
     Operations --> Review["Review and interview reasoning"]
 ```
 
+## Engineering Quality
+
+Repository quality is enforced through small, reviewable changes and automated verification:
+
+- **Continuous integration:** every push to `main` or a feature branch and every pull request to `main` restores, builds, and verifies the executable examples in Release mode.
+- **Strict compilation:** CI treats compiler warnings as errors to prevent warning debt from entering the stable branch.
+- **Behavior verification:** `dotnet run -- verify` exercises the example decision paths and fails fast when expected outcomes drift.
+- **Documentation integrity:** Markdown links are checked automatically when documentation changes.
+- **Reproducible tooling:** workflows install the .NET 10 SDK explicitly instead of relying on the runner's preinstalled SDKs.
+
 ## Module Index
 
 | Module | Engineering area | Code examples |
@@ -53,21 +67,22 @@ flowchart LR
 
 Every module contains:
 
-- `README.md` — decision-oriented overview and navigation;
-- `Theory.md` — language and runtime semantics;
-- `BestPractices.md` — implementation and review checklist;
-- `CommonMistakes.md` — production failure patterns;
-- `InterviewQuestions.md` — 10 senior-level questions with answers;
-- `ProductionNotes.md` — enterprise use, memory, performance, and Microsoft-aligned recommendations;
-- compileable `.cs` examples using orders, payments, users, claims, services, and infrastructure boundaries.
+- `README.md` - decision-oriented overview and navigation
+- `Theory.md` - language and runtime semantics
+- `BestPractices.md` - implementation and review checklist
+- `CommonMistakes.md` - production failure patterns
+- `InterviewQuestions.md` - 10 senior-level questions with answers
+- `ProductionNotes.md` - enterprise use, memory, performance, and Microsoft-aligned recommendations
+- compileable `.cs` examples using orders, payments, users, claims, services, and infrastructure boundaries
 
 ## Runnable Scenarios
 
-The application includes executable order processing, payment validation, and notification dispatch examples.
+The application includes executable order processing, payment validation, and notification dispatch examples, plus a built-in verification command for deterministic behavior checks.
 
 ```bash
 dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamentals.csproj
 dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamentals.csproj -- payment
+dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamentals.csproj -- verify
 ```
 
 See the [execution guide](./examples/README.md).
@@ -79,27 +94,23 @@ Requires the [.NET 10 SDK](https://dotnet.microsoft.com/download/dotnet/10.0).
 ```bash
 dotnet restore src/CSharpFundamentals/CSharpFundamentals.slnx
 dotnet build src/CSharpFundamentals/CSharpFundamentals.slnx --configuration Release
+dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamentals.csproj --configuration Release --no-build -- verify
 ```
 
+## Technical Blog Watch
+
+- [.NET Team: Announcing .NET 10](https://devblogs.microsoft.com/dotnet/announcing-dotnet-10/) explains the runtime, language, and tooling release this repository targets.
+
 ## Repository Structure
 
 ```text
 csharp-fundamentals/
-├── assets/
-├── examples/
-└── src/CSharpFundamentals/CSharpFundamentals/
-    ├── Examples/                  # Executable cross-topic scenarios
-    └── Modules/
-        ├── 01-Variables/
-        ├── 02-DataTypes/
-        ├── 03-TypeConversion/
-        ├── 04-Operators/
-        ├── 05-Strings/
-        ├── 06-Arrays/
-        ├── 07-Methods/
-        ├── 08-ControlFlow/
-        ├── 09-ExceptionHandling/
-        └── 10-Namespaces/
+|-- assets/
+|-- examples/
+`-- src/CSharpFundamentals/CSharpFundamentals/
+    |-- Examples/       # Executable cross-topic scenarios
+    |-- Modules/
+    `-- Verification/   # Built-in behavior checks for the examples
 ```
 
 ## Contribution Standard

examples/README.md

@@ -1,6 +1,6 @@
 # Runnable Backend Examples
 
-[← Repository home](../README.md) · [Module index](../README.md#module-index)
+[Repository home](../README.md) | [Module index](../README.md#module-index)
 
 These examples are small enough to run locally while using domains and design concerns found in backend services.
 
@@ -10,6 +10,14 @@ These examples are small enough to run locally while using domains and design co
 dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamentals.csproj
 ```
 
+## Verify Expected Behavior
+
+```bash
+dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamentals.csproj -- verify
+```
+
+The `verify` command checks the reusable order, payment, and notification decision paths so regressions surface before a pull request is opened.
+
 ## Available Examples
 
 | Argument | Scenario | Concepts |
@@ -26,9 +34,9 @@ dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamental
 
 Expected behavior:
 
-- validates customer and line data;
-- calculates subtotal, tax, and total;
-- flags orders at or above the review threshold.
+- validates customer and line data
+- calculates subtotal, tax, and total
+- flags orders at or above the review threshold
 
 ### Payment Validation
 
@@ -38,9 +46,9 @@ dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamental
 
 Expected behavior:
 
-- rejects invalid amounts or unsupported currencies;
-- routes high-risk or large payments to manual review;
-- returns a decision object rather than using exceptions for expected outcomes.
+- rejects invalid amounts or unsupported currencies
+- routes high-risk or large payments to manual review
+- returns a decision object rather than using exceptions for expected outcomes
 
 ### Notification Dispatch
 
@@ -50,9 +58,9 @@ dotnet run --project src/CSharpFundamentals/CSharpFundamentals/CSharpFundamental
 
 Expected behavior:
 
-- resolves a user through a repository interface;
-- respects notification preferences;
-- sends through an asynchronous gateway with cancellation support.
+- resolves a user through a repository interface
+- respects notification preferences
+- sends through an asynchronous gateway with cancellation support
 
 ## Practice Extensions
 

src/CSharpFundamentals/CSharpFundamentals/Examples/NotificationDispatchExample.cs

@@ -21,65 +21,4 @@ public async Task RunAsync(CancellationToken cancellationToken)
 
         Console.WriteLine($"Notification status: {result.Status}");
     }
-
-    private interface IUserRepository
-    {
-        Task<User?> FindAsync(Guid userId, CancellationToken cancellationToken);
-    }
-
-    private interface IMessageGateway
-    {
-        Task SendAsync(string destination, string message, CancellationToken cancellationToken);
-    }
-
-    private sealed class NotificationService(
-        IUserRepository users,
-        IMessageGateway gateway)
-    {
-        public async Task<NotificationResult> NotifyAsync(
-            Guid userId,
-            string message,
-            CancellationToken cancellationToken)
-        {
-            User? user = await users.FindAsync(userId, cancellationToken);
-
-            if (user is null)
-                return new NotificationResult("User not found");
-
-            if (!user.NotificationsEnabled)
-                return new NotificationResult("Notifications disabled");
-
-            await gateway.SendAsync(user.Email, message, cancellationToken);
-            return new NotificationResult("Sent");
-        }
-    }
-
-    private sealed class InMemoryUserRepository(IEnumerable<User> users) : IUserRepository
-    {
-        private readonly IReadOnlyDictionary<Guid, User> _users =
-            users.ToDictionary(user => user.Id);
-
-        public Task<User?> FindAsync(Guid userId, CancellationToken cancellationToken)
-        {
-            cancellationToken.ThrowIfCancellationRequested();
-            _users.TryGetValue(userId, out User? user);
-            return Task.FromResult(user);
-        }
-    }
-
-    private sealed class ConsoleMessageGateway : IMessageGateway
-    {
-        public async Task SendAsync(
-            string destination,
-            string message,
-            CancellationToken cancellationToken)
-        {
-            await Task.Delay(25, cancellationToken);
-            Console.WriteLine($"Sending to {destination}: {message}");
-        }
-    }
-
-    private sealed record User(Guid Id, string Email, bool NotificationsEnabled);
-
-    private sealed record NotificationResult(string Status);
 }

src/CSharpFundamentals/CSharpFundamentals/Examples/NotificationDispatchScenario.cs

@@ -0,0 +1,62 @@
+namespace CSharpFundamentals.Examples;
+
+internal interface IUserRepository
+{
+    Task<User?> FindAsync(Guid userId, CancellationToken cancellationToken);
+}
+
+internal interface IMessageGateway
+{
+    Task SendAsync(string destination, string message, CancellationToken cancellationToken);
+}
+
+internal sealed class NotificationService(
+    IUserRepository users,
+    IMessageGateway gateway)
+{
+    public async Task<NotificationResult> NotifyAsync(
+        Guid userId,
+        string message,
+        CancellationToken cancellationToken)
+    {
+        User? user = await users.FindAsync(userId, cancellationToken);
+
+        if (user is null)
+            return new NotificationResult("User not found");
+
+        if (!user.NotificationsEnabled)
+            return new NotificationResult("Notifications disabled");
+
+        await gateway.SendAsync(user.Email, message, cancellationToken);
+        return new NotificationResult("Sent");
+    }
+}
+
+internal sealed class InMemoryUserRepository(IEnumerable<User> users) : IUserRepository
+{
+    private readonly IReadOnlyDictionary<Guid, User> _users =
+        users.ToDictionary(user => user.Id);
+
+    public Task<User?> FindAsync(Guid userId, CancellationToken cancellationToken)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        _users.TryGetValue(userId, out User? user);
+        return Task.FromResult(user);
+    }
+}
+
+internal sealed class ConsoleMessageGateway : IMessageGateway
+{
+    public async Task SendAsync(
+        string destination,
+        string message,
+        CancellationToken cancellationToken)
+    {
+        await Task.Delay(25, cancellationToken);
+        Console.WriteLine($"Sending to {destination}: {message}");
+    }
+}
+
+internal sealed record User(Guid Id, string Email, bool NotificationsEnabled);
+
+internal sealed record NotificationResult(string Status);