Mastering Unit Testing in SwiftUI: Build a Task Tracker

Name: Mastering Unit Testing in SwiftUI: Build a Task Tracker
Rating: 3.8 (3 reviews)

Build a real SwiftUI app with full unit testing and architecture skills used by professional iOS teams.

Created byNorbert Grover

Last updated 6/2025

English

What you'll learn

Build a complete to-do list app using SwiftUI and MVVM architecture.
Write unit tests for models, view models, and storage layers in a SwiftUI app.
Learn how to use dependency injection to make code more testable and modular.
Create and use mock objects to isolate logic and write predictable unit tests.
Implement a progress-tracking feature that updates as tasks are completed.
Use XCTest to write assertions, verify app behavior, and prevent regressions.
Structure and organize your Swift project for scalability and maintainability.
Configure Xcode to collect and analyze code coverage metrics.
Understand the difference between unit tests, integration tests, and UI tests.
Develop the testing mindset required for mid- to senior-level iOS engineering roles.

Course content

3 sections • 14 lectures • 2h 48m total length

Introduction to the project2:21
In the resources file, there is a link to the GitHub repo so that you can clone the finished product to your Mac.
What the Habit Tracker looks like and how it actually operates.2:25
In this video, we’ll walk through the functionality of the Habit Tracker app built in this course. You’ll see how the app allows users to:
Add new tasks or habits with a custom name
View a dynamic list of all current habits
Mark habits as complete or incomplete with a single tap
View real-time progress updates as tasks are completed
Reset the habit list or toggle individual task states
Track total and completed habit counts
Persist data locally across app sessions
This demo highlights the polished user experience and clean SwiftUI interface, but it’s what’s under the hood that matters most.

Creating the Model2:41
In this video, you'll learn how to define the core Habit model that powers our task-tracking app. We'll walk through how to structure the model using Swift’s struct, add essential properties like id, name, and isCompleted, and make it conform to Identifiable, Codable, and Equatable—all critical for SwiftUI views, persistence, and unit testing. This foundational step is key to building a scalable and testable SwiftUI application.
Creating the HabitStorage Service and Protocol in Swift22:34
In this video, we implement the HabitStorage service—our app’s persistence layer—along with the HabitStorageProtocol it conforms to. You’ll learn how to design a clean abstraction for saving and loading habit data using UserDefaults, while adhering to protocol-oriented programming principles. This separation of concerns ensures your app remains modular, testable, and easy to extend or replace in the future. Whether you're preparing for interviews or writing production-level SwiftUI code, understanding this pattern is essential.
Building the HabitViewModel in SwiftUI (MVVM)23:41
In this video, we build the HabitViewModel, the core logic layer that connects the user interface to the data in our SwiftUI app. You’ll learn how to manage app state using @Published, respond to user interactions, and use dependency injection to connect the view model to a storage service. This is a hands-on implementation of the MVVM design pattern, structured for clarity, scalability, and testability—exactly how real-world SwiftUI apps should be built.
Building the SwiftUI View for the Habit Tracker App29:41
In this video, we create the main SwiftUI view that powers the user interface of the Habit Tracker app. You'll learn how to use @ObservedObject to connect to the HabitViewModel, design a clean and interactive layout using VStack, List, ProgressView, and buttons, and bind user input with @State. We'll also show how to use system symbols and custom styling to give the interface a polished, intuitive feel. This video brings together architecture and UI to form a responsive, real-world SwiftUI experience.

Why unit tests are important0:56
Unit Tests vs. Integration Tests0:50
Writing Unit Tests for EnumerationValues in Swift16:57
In this video, we create the EnumerationValuesTests file to verify the integrity of our app’s constants. You’ll learn how to write simple but effective tests to ensure that your storage keys, system symbols, and UI strings are correctly defined and don’t silently break as the project evolves. Even though enums often seem “safe,” validating them helps maintain reliability across the codebase—especially in production apps.
Creating Integration Tests for HabitStorage in Swift17:10
n this video, we build HabitStorageIntegrationTests to ensure that our storage layer works as expected with real data. You'll learn how to simulate saving and loading habits using UserDefaults, verify data persistence across app sessions, and test the actual behavior of your storage service without mocks. These integration tests are a crucial step toward validating your app's architecture under realistic conditions—ensuring data flows reliably from storage to the user interface.
Testing Extensions with HabitTrackerExtensionTests in Swift11:24
In this video, we create HabitTrackerExtensionTests to validate utility extensions used across our app—specifically the Double.asPercent computed property. You'll learn why testing extensions is essential for maintaining correctness in utility logic, and how to write focused unit tests that catch formatting issues or edge cases early. This reinforces your habit of testing every layer of your codebase, even those that seem trivial.
Writing Unit Tests for the Habit Model in Swift - part 113:04
In this video, we create HabitTrackerModelTests to verify the behavior and integrity of the Habit model. You’ll learn how to test initialization, equality, identity, and encoding/decoding functionality to ensure your model conforms to Codable, Equatable, and Identifiable correctly. These tests form the foundation of a reliable codebase, catching subtle issues early and ensuring the core data structure behaves exactly as expected.
Writing Unit Tests for the Habit Model in Swift - part 28:52
In this video, we create HabitTrackerModelTests to verify the behavior and integrity of the Habit model. You’ll learn how to test initialization, equality, identity, and encoding/decoding functionality to ensure your model conforms to Codable, Equatable, and Identifiable correctly. These tests form the foundation of a reliable codebase, catching subtle issues early and ensuring the core data structure behaves exactly as expected.
Unit Testing in Swift: HabitTrackerViewModelTests Explained15:25
In this video, we dive deep into the unit tests behind a SwiftUI-based habit tracking app. We'll walk through the HabitTrackerViewModelTests test suite, showing how each function validates key behaviors of the HabitViewModel. From adding, removing, and clearing habits to testing completion status, progress tracking, and data persistence with mock storage—this comprehensive suite ensures your app logic stays reliable and bug-free.

Requirements

Basic knowledge of Swift programming (variables, functions, optionals, control flow).
Familiarity with SwiftUI fundamentals such as Views, State, and Bindings.
Comfort using Xcode (creating projects, navigating the interface, running simulators).
Experience building simple SwiftUI apps (no need for production experience).
Understanding of MVVM architecture basics is helpful but not mandatory.
Mac with Xcode installed (preferably the latest stable version).
Access to a macOS environment capable of running Xcode and iOS simulators.
Basic familiarity with Git and source control is a plus for managing changes.
Willingness to learn professional development workflows, including testing and debugging.
Some prior exposure to writing tests in any language is helpful but not required—testing concepts will be explained from the ground up.

Description

Like many self-taught iOS developers, I’ve taken my share of online courses — and I’ve noticed a frustrating pattern: most courses either skip unit testing entirely or cover it in abstract, unrealistic ways. You’re shown how XCTest works in isolation, but never how it fits into an actual app. This course fixes that.

In this course, you’ll build a fully functional SwiftUI to-do list app with all the real-world features you’d expect: task management, progress tracking, persistent storage, and completion toggles. But what sets this course apart is the testing. You won’t just “learn” unit testing — you’ll apply it meaningfully inside a real architecture, with a proper ViewModel, mocking, and dependency injection.

Every unit test in this course serves a purpose. I walk you through how and why to test each part of the system — not just happy paths, but edge cases, error handling, and persistent state. You’ll gain an intuition for when tests matter and how to write them so they’re fast, clear, and maintainable.

If you’re tired of courses that barely scratch the surface or leave testing as an afterthought, this course is for you. There isn’t a more realistic or comprehensive course on unit testing in SwiftUI available today.

By the end, you’ll not only have a polished, production-grade app in your portfolio — you’ll also have the testing skills that set real iOS developers apart from the crowd.

Who this course is for:

iOS developers seeking to deepen their understanding of unit testing within SwiftUI.
Junior developers working toward mid-level roles who want real-world project experience.
Developers transitioning from UIKit to SwiftUI looking to adopt modern development and testing workflows.
Bootcamp graduates who received little or no training in software testing.
Self-taught programmers who want to build testable, maintainable SwiftUI apps.
Freelance iOS developers who need to produce professional-grade applications for clients.
Computer science students aiming to strengthen their practical knowledge before entering the job market.
Mid-level developers preparing for senior roles by improving their code quality and testing discipline.
Developers working in teams with CI/CD pipelines who need reliable automated test suites.
Anyone who has built SwiftUI apps and now wants to learn how to properly test them.

Mastering Unit Testing in SwiftUI: Build a Task Tracker

What you'll learn

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Course content

Introduction2 lectures • 5min

Follow Along with the Coding4 lectures • 1hr 19min

Unit Testing and Quality Control8 lectures • 1hr 25min

Requirements

Description

Who this course is for: