You have to update your extension method to the following public static IEnumerable<T> NotNull<T>(this IEnumerable<T?> enumerable) where T : class { return enumerable.Where(e => e != null).Select(e => e!); } The point here is that you are converting the IEnumerable of nullable references to not nullable ones, therefore you’ll have to use IEnumerable<T?>. where T … Read more
To workaround the issue, add the code ENV ASPNETCORE_URLS=http://+:80 below the other ENV declarations at the top of the Dockerfile.develop file Dockerfile.develop after: FROM mcr.microsoft.com/dotnet/core/sdk:3.1 ARG BUILD_CONFIGURATION=Debug ENV ASPNETCORE_ENVIRONMENT=Development ENV DOTNET_USE_POLLING_FILE_WATCHER=true ENV ASPNETCORE_URLS=http://+:80 EXPOSE 80 Explanation Server URLs is one of the ASP.NET Core Web Host configuration values. It uses the environment variable ASPNETCORE_URLS and … Read more
Given a function in a program using C# 8.0’s nullable reference types feature, should I still be performing null checks on the arguments? That depends on how certain you are of all the paths through your API. Consider this code: public void Foo(string x) { FooImpl(x); } private void FooImpl(string x) { … } Here … Read more
As an option, you can use the default literal in combination with the null forgiving operator public class Item { public string Id { get; set; } = default!; public string Name { get; set; } = default!; public string Description { get; set; } = default!; } Since your DTO is populated from DynamoDB, … Read more
If you install the System.Linq.Async package, you should be able to use AsyncEnumable.Empty<string>(). Here’s a complete example: using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; class Program { static async Task Main() { IAsyncEnumerable<string> empty = AsyncEnumerable.Empty<string>(); var count = await empty.CountAsync(); Console.WriteLine(count); // Prints 0 } }
LINQ for IAsyncEnumerable is supported by System.Linq.Async which is part of the reactive extensions for .NET. The reactive extensions as a whole are split into two larger NuGet packages: System.Reactive and System.Interactive. While all the packages stayed the same, the extensions now live in the System.Linq namespace, not System.Linq.Async anymore (thanks Dzmitry Lahoda). Relevant GitHub … Read more
Whenever you want to tell the compiler “shut up, I know what I’m doing” in regards to nullable reference types, use the ! operator. You can fix your issue by declaring your properties like so: public DbSet<Probe> Probes { get; set; } = null!; public DbSet<ProbeUnitTest> ProbeUnitTests { get; set; } = null!;
It seems, that you have two possible options here. First one is to initialize an Options properties using empty string (instead of null value) to avoid null checks public sealed class MyOptions { public string Name { get; set; } = “”; } Second one is to make all of the properties a nullable ones … Read more
TL;DR It is not possible. In C# 8 switch expression cannot return void. It must return a value and this value must be consumed (assigned to a variable, passed as an argument to a method, returned as a result of a method, etc.). But there is a workaround. We can write a switch expression that … Read more
Going forward, Microsoft want to tie C# language versions more closely to framework versions than they have in the past. They really only want you to be using C# 8 with .NET Core 3.x and .NET Standard 2.1 projects, and that means using Visual Studio 2019. My answer to Does C# 8 support the .NET … Read more