Syllabus

ASP.NET Core Complete Tutorial (ShopNest)

Module 1: Foundations
What is ASP.NET Core? Complete Guide Setting Up ASP.NET Core Development Environment ASP.NET Core Project Structure Explained MVC Architecture in ASP.NET Core — Complete Guide Controllers and Actions in ASP.NET Core Routing in ASP.NET Core — Conventional and Attribute Routing Views and Razor Syntax in ASP.NET Core Layouts, Partial Views and View Components Models and ViewModels in ASP.NET Core Forms, Model Binding and Validation in ASP.NET Core Tag Helpers in ASP.NET Core — Complete Guide Static Files, Bundling and Minification in ASP.NET Core
Module 2: Entity Framework Core
Entity Framework Core — Introduction and Setup EF Core Code First — Models, Migrations, Database EF Core CRUD Operations — Create, Read, Update, Delete EF Core LINQ Queries — Beginner to Advanced EF Core Relationships — One-to-One, One-to-Many, Many-to-Many EF Core Fluent API — Advanced Configuration EF Core Repository Pattern and Unit of Work EF Core Performance Optimization Database First Approach with EF Core (Scaffold) EF Core with SQL Server — Advanced Features
Module 3: Dependency Injection & Middleware
Dependency Injection in ASP.NET Core — Complete Guide Middleware in ASP.NET Core — Complete Guide Configuration in ASP.NET Core — appsettings, Environment Variables, Secrets Filters in ASP.NET Core — Action, Authorization, Exception, Resource, Result Logging in ASP.NET Core — ILogger, Serilog, NLog Error Handling and Exception Management in ASP.NET Core
Module 4: Authentication & Security
ASP.NET Core Identity — Complete Setup Guide Authentication in ASP.NET Core — Cookie and JWT Authorization in ASP.NET Core — Roles, Policies, Claims JWT Authentication with Refresh Tokens — Complete Implementation OAuth2 and External Login (Google, Facebook, Microsoft) Data Protection and Encryption in ASP.NET Core HTTPS, SSL Certificates and Security Best Practices
Module 5: Web API
Building REST APIs with ASP.NET Core — Complete Guide API Versioning in ASP.NET Core Swagger / OpenAPI Documentation in ASP.NET Core Input Validation in Web APIs — FluentValidation and Data Annotations Pagination, Filtering and Sorting in ASP.NET Core APIs HTTP Client and Consuming External APIs in ASP.NET Core Minimal APIs in ASP.NET Core .NET 8 SignalR — Real-Time Web Applications
Module 6: Advanced Architecture
Clean Architecture in ASP.NET Core CQRS Pattern with MediatR in ASP.NET Core Repository Pattern — Deep Dive with Generic Repository Background Services and Hosted Services in ASP.NET Core Caching in ASP.NET Core — In-Memory, Distributed, Redis Health Checks in ASP.NET Core AutoMapper in ASP.NET Core Microservices with ASP.NET Core — Introduction Message Queues with RabbitMQ / Azure Service Bus in ASP.NET Core gRPC with ASP.NET Core
Module 7: Testing
Unit Testing ASP.NET Core with xUnit and Moq Integration Testing in ASP.NET Core Testing EF Core — In-Memory vs SQLite Performance Testing and Load Testing ASP.NET Core APIs Test-Driven Development (TDD) in ASP.NET Core
Module 8: Deployment & DevOps
Deploying ASP.NET Core to IIS on Windows Server Docker and Containerization for ASP.NET Core Deploying ASP.NET Core to Azure App Service CI/CD with GitHub Actions for ASP.NET Core Azure SQL Database with ASP.NET Core Environment Configuration and Secrets Management
Module 9: Real-World Projects
Build a Complete Blog Website with ASP.NET Core MVC Build an E-Commerce Product Catalog API (ASP.NET Core Web API) Build a Student Management System (Complete CRUD App) Build a Job Portal (Full Stack ASP.NET Core) Build a REST API with Clean Architecture — Complete Guide Build a Real-Time Chat App with SignalR and ASP.NET Core
Module 10: Advanced Topics
Blazor WebAssembly and Blazor Server — Complete Guide gRPC, GraphQL and Alternative API Styles in ASP.NET Core Rate Limiting and API Throttling in ASP.NET Core .NET 8 Output Caching in ASP.NET Core .NET 8 ASP.NET Core .NET 9 New Features — Complete Guide
ASP.NET Core Complete Tutorial (ShopNest)
Lesson 58 of 75 77% of course

Test-Driven Development (TDD) in ASP.NET Core

1 · 5 min · 5/24/2026

Learn Test-Driven Development (TDD) in ASP.NET Core in our free ASP.NET Core Complete Tutorial (ShopNest) series. Step-by-step explanations, examples, and interview tips on Toolliyo Academy.

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Test-Driven Development (TDD) in ASP.NET Core — ShopNest
Article 58 of 75 · Module 7: Testing · ShopNest Building a Feature TDD-Style
Target keyword: tdd asp.net core · Read time: ~31 min · .NET: 8 / 9 · Project: ShopNest Building a Feature TDD-Style

Introduction

TDD — Red, Green, Refactor — builds ShopNest's promo code discount feature test-first: write failing test, minimal code to pass, then clean up. Honest take: great for domain logic; less ideal for UI scaffolding.

After this article you will

  • Apply Red-Green-Refactor cycle
  • TDD a service method from failing test outward
  • Choose mocking strategy during TDD
  • Know when TDD helps vs slows delivery
  • Avoid common TDD pitfalls

Prerequisites

Concept deep-dive

RED   → Write failing test for ApplyPromoCodeAsync
GREEN → Minimal implementation: if code=="SAVE10" discount=10%
REFACTOR → Extract IPromoRuleEngine, remove duplication
// Step 1 — RED (test fails — no implementation yet)
[Fact]
public async Task ApplyPromoCode_ValidCode_AppliesTenPercent()
{
    var order = new Order { Subtotal = 1000m };
    await _sut.ApplyPromoCodeAsync(order, "SAVE10");
    Assert.Equal(100m, order.Discount);
    Assert.Equal(900m, order.Total);
}

// Step 2 — GREEN (minimal)
public Task ApplyPromoCodeAsync(Order order, string code)
{
    if (code == "SAVE10") order.ApplyDiscount(order.Subtotal * 0.10m);
    return Task.CompletedTask;
}

// Step 3 — REFACTOR — PromoRuleEngine with pluggable rules

When TDD helps: pricing, tax, inventory rules. When it slows: CRUD scaffolding, spike/prototype, heavy UI — use tests after or integration tests instead.

Hands-on — ShopNest Building a Feature TDD-Style

  1. Promo code feature entirely TDD from first test.
  2. Tests: invalid code, expired code, max discount cap, stackable rules.
  3. Refactor to PromoRuleEngine + IPromoRepository.
  4. API endpoint added last with integration test.

Common errors & best practices

  • Writing tests after code and calling it TDD — order matters.
  • Tests too large — one behavior per test drives design.
  • Skipping refactor step — debt accumulates in green phase.
  • TDD on everything including layout pages — wrong tool.

Interview questions

Q: Red-Green-Refactor?
A: Fail test → pass minimally → improve design without changing behavior.

Q: TDD drawbacks?
A: Learning curve; slower initial UI work; requires discipline.

Q: Emergent design?
A: API of classes shaped by testability needs over upfront UML.

Summary

  • TDD excels on ShopNest pricing and promo rules
  • Red-Green-Refactor is the core rhythm
  • Mock at boundaries while driving service design
  • Skip TDD for pure CRUD — add integration tests instead

Previous: Performance and Load Testing
Next: Deploying to IIS

FAQ

TDD mandatory at TCS/Infosys?

Varies by project — knowing TDD is interview plus.

BDD vs TDD?

BDD uses Given-When-Then specs (SpecFlow) — business-readable tests.

Interview Q&A for this course

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ASP.NET Core Complete Tutorial (ShopNest)

On this page

Introduction After this article you will Prerequisites Concept deep-dive Hands-on — ShopNest Building a Feature TDD-Style Common errors & best practices Interview questions Summary FAQ TDD mandatory at TCS/Infosys? BDD vs TDD?
Module 1: Foundations
What is ASP.NET Core? Complete Guide Setting Up ASP.NET Core Development Environment ASP.NET Core Project Structure Explained MVC Architecture in ASP.NET Core — Complete Guide Controllers and Actions in ASP.NET Core Routing in ASP.NET Core — Conventional and Attribute Routing Views and Razor Syntax in ASP.NET Core Layouts, Partial Views and View Components Models and ViewModels in ASP.NET Core Forms, Model Binding and Validation in ASP.NET Core Tag Helpers in ASP.NET Core — Complete Guide Static Files, Bundling and Minification in ASP.NET Core
Module 2: Entity Framework Core
Entity Framework Core — Introduction and Setup EF Core Code First — Models, Migrations, Database EF Core CRUD Operations — Create, Read, Update, Delete EF Core LINQ Queries — Beginner to Advanced EF Core Relationships — One-to-One, One-to-Many, Many-to-Many EF Core Fluent API — Advanced Configuration EF Core Repository Pattern and Unit of Work EF Core Performance Optimization Database First Approach with EF Core (Scaffold) EF Core with SQL Server — Advanced Features
Module 3: Dependency Injection & Middleware
Dependency Injection in ASP.NET Core — Complete Guide Middleware in ASP.NET Core — Complete Guide Configuration in ASP.NET Core — appsettings, Environment Variables, Secrets Filters in ASP.NET Core — Action, Authorization, Exception, Resource, Result Logging in ASP.NET Core — ILogger, Serilog, NLog Error Handling and Exception Management in ASP.NET Core
Module 4: Authentication & Security
ASP.NET Core Identity — Complete Setup Guide Authentication in ASP.NET Core — Cookie and JWT Authorization in ASP.NET Core — Roles, Policies, Claims JWT Authentication with Refresh Tokens — Complete Implementation OAuth2 and External Login (Google, Facebook, Microsoft) Data Protection and Encryption in ASP.NET Core HTTPS, SSL Certificates and Security Best Practices
Module 5: Web API
Building REST APIs with ASP.NET Core — Complete Guide API Versioning in ASP.NET Core Swagger / OpenAPI Documentation in ASP.NET Core Input Validation in Web APIs — FluentValidation and Data Annotations Pagination, Filtering and Sorting in ASP.NET Core APIs HTTP Client and Consuming External APIs in ASP.NET Core Minimal APIs in ASP.NET Core .NET 8 SignalR — Real-Time Web Applications
Module 6: Advanced Architecture
Clean Architecture in ASP.NET Core CQRS Pattern with MediatR in ASP.NET Core Repository Pattern — Deep Dive with Generic Repository Background Services and Hosted Services in ASP.NET Core Caching in ASP.NET Core — In-Memory, Distributed, Redis Health Checks in ASP.NET Core AutoMapper in ASP.NET Core Microservices with ASP.NET Core — Introduction Message Queues with RabbitMQ / Azure Service Bus in ASP.NET Core gRPC with ASP.NET Core
Module 7: Testing
Unit Testing ASP.NET Core with xUnit and Moq Integration Testing in ASP.NET Core Testing EF Core — In-Memory vs SQLite Performance Testing and Load Testing ASP.NET Core APIs Test-Driven Development (TDD) in ASP.NET Core
Module 8: Deployment & DevOps
Deploying ASP.NET Core to IIS on Windows Server Docker and Containerization for ASP.NET Core Deploying ASP.NET Core to Azure App Service CI/CD with GitHub Actions for ASP.NET Core Azure SQL Database with ASP.NET Core Environment Configuration and Secrets Management
Module 9: Real-World Projects
Build a Complete Blog Website with ASP.NET Core MVC Build an E-Commerce Product Catalog API (ASP.NET Core Web API) Build a Student Management System (Complete CRUD App) Build a Job Portal (Full Stack ASP.NET Core) Build a REST API with Clean Architecture — Complete Guide Build a Real-Time Chat App with SignalR and ASP.NET Core
Module 10: Advanced Topics
Blazor WebAssembly and Blazor Server — Complete Guide gRPC, GraphQL and Alternative API Styles in ASP.NET Core Rate Limiting and API Throttling in ASP.NET Core .NET 8 Output Caching in ASP.NET Core .NET 8 ASP.NET Core .NET 9 New Features — Complete Guide