Category: Programming

July 11, 2022 Programming 2 Comments

Typing API Responses With Zod

Have you ever needed to synchronize types in your frontend app with the backend API?

If you ever had an API action defined like that in your controller:

public record UserViewModel(Guid Id, string Name, string LastName, string Login,
bool IsActive, int LoyaltyPoints, AddressViewModel? Address = null);
// …
public List<UserViewModel> AllUsers()
{
var usersViewModels = TestDataGenerator.GetTestUsers();
return usersViewModels.OrderBy(uvm => uvm.Name).ToList();
}
view raw AspNetControllerSample.cs hosted with ❤ by GitHub

and fetched this data using TypeScript in the following way:

getAllUsers = async (): Promise<UserViewModel[]> => {
const url = `${this.apiEndpoint}/AllUsers`;
const response = await fetch(url);
const users = (await response.json()) as UserViewModel[];
return users;
};
view raw ApiFetchSample.ts hosted with ❤ by GitHub

at some point, you probably also experienced the desynchronization of backend (C#, in our example) and frontend (TypeScript) types definitions. What if someone has changed the C# version of UserViewModel, but no one corrected its TypeScript’s equivalent?

Your TypeScript fetching code will tell nothing about that. There will be no error, even though the fetched data doesn’t match the expected UserViewModel type.

I’ll try to address this issue in this article 🙂 Let’s see how typing API responses with zod can help us here.

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June 19, 2022 Programming Post a Comment

Write Test Progress To The Console With NUnit

NUnit: writing test progress to the console

I recently needed to write test progress to the console with NUnit. The task we want to solve here is basically the TODO part of this snippet:

[TestFixture]
public class MyTests
{
[Test]
public void SampleTest()
{
// some operations here, like starting a server for tests in-memory…
// TODO: inform the 'user' (the one who runs the test) that the server is already running
while (true)
{
// keep it running on purpose (e.g. for E2E tests)
}
}
}
view raw NUnit_test_progress_todo.cs hosted with ❤ by GitHub

The title picture of this article shows the end result. If you want to know the solution, keep reading 🙂

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May 17, 2022 Programming Post a Comment

How To Fix SqlException Database Is Not Currently Available On Azure (0x80131904)

I recently deployed my .NET 6 application to Microsoft Azure. The app uses NHibernate for working with SQL Server database. After some time, I started getting an unhandled exception when opening the application:

NHibernate.Exceptions.GenericADOException: could not load an entity: 
...
 ---> Microsoft.Data.SqlClient.SqlException (0x80131904): Database 'myappdb' on server 'myapp.database.windows.net' is not currently available.  Please retry the connection later.  If the problem persists, contact customer support, and provide them the session tracing ID of '{EB501CF2-2F21-4E28-9042-2B83EEE57B91}'.

The database is not currently available was very interesting to me. I struggled a bit with solving that, so if you want to know how I did it – continue reading 🙂

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August 29, 2020 Programming Post a Comment

Is It Worth Migrating to TypeScript?

Is it worth migrating to TypeScript?

For the past year I’ve been working on a JavaScript project for my client. We have a mid-size web application. We use React as the web development framework. Few months ago we decided to start migrating to TypeScript.

Today I can say that it was the best decision we could make. TypeScript makes working with JavaScript, which is sometimes surprising and quite hard to understand, so much better experience. However, there were some challenges on this journey. If you want to know what issues we met and how we solved them, but also what huge advantages TypeScript gave us – read on 😉

I will not discuss TypeScript itself in this article. This is a pure recap of challenges and the experience I gained when migrating to TypeScript.

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October 2, 2019 Programming Post a Comment

How to Start Working with an Unknown Codebase?

If you’ve ever joined a new project you probably know the excitement of being presented with a brand new source code. As soon as you’re assigned your first tasks the excitement turns into frustration, because it’s not easy to fix this simple bug… Even you’re an experienced developer.

Today I’m trying to address the issue of approaching an unknown codebase. I’ll give you some advices and tricks I’m using to make new code easier and quicker to understand – even without understanding it all 🙂

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