Tag: .NET

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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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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October 11, 2018 Programming 2 Comments

[.NET Internals 10] Application execution model

Knowing the idea and main benefits of JIT compilation from the previous post, we’ll now see how it fits into .NET applications execution model.

By execution model I mean a process of having a .NET Framework application actually executed on the machine (CPU), starting from having its source code written. It contains all steps and actions necessary to happen in order to transform source code (like C#) into machine (assembly) code and execute it.

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