ASP.NET Core 2.2 -> 3.0 upgrade. env.IsDevelopment() not found

As Rena says IsDevelopment has been moved to IHostEnvironment Interface in the Microsoft.Extensions.Hosting Namespace

I just had to add the

using Microsoft.Extensions.Hosting;

and then I could use IsDevelopment() as before.

The new IHostEnvironment, IsDevelopment, IsProduction etc. extension methods are in the Microsoft.Extensions.Hosting namespace which may need to be added to your app.

Reference:

https://docs.microsoft.com/en-us/aspnet/core/migration/22-to-30?view=aspnetcore-3.0&tabs=visual-studio#migrate-startupconfigure

https://github.com/aspnet/AspNetCore/issues/7749

int the extension:

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;

public static class HostingEnvironmentExtensions
{
    public static IConfigurationRoot GetAppConfiguration(this IWebHostEnvironment env)
    {
        return AppConfigurations.Get(env.ContentRootPath, env.EnvironmentName, env.IsDevelopment());
    }
}