ASP.NET Core – Error CS0266 Cannot implicitly convert type StackExchange.Redis.Extensions.Core.Configuration.RedisConfiguration

In my ASP.NET Core-6 Web API, I am implementing Redis for In-Memory Cache. I installed this extensions:

<PackageReference Include="StackExchange.Redis.Extensions.AspNetCore" Version="9.1.0" />
<PackageReference Include="StackExchange.Redis.Extensions.Newtonsoft" Version="9.1.0" />

Then I have this code for the dependency injection:

public static class DIServices
{
    public static void AddDI(this IServiceCollection services)
    {
        services.AddStackExchangeRedisExtensions<NewtonsoftSerializer>( options =>
        {
            return new RedisConfiguration();
        });
    }
}

And in Program.cs:

builder.Services.AddDI();

However, I got this error:

Severity    Code    Description Project File    Line    Suppression State
Error   CS0266  Cannot implicitly convert type 'StackExchange.Redis.Extensions.Core.Configuration.RedisConfiguration' to 'System.Collections.Generic.IEnumerable<StackExchange.Redis.Extensions.Core.Configuration.RedisConfiguration>'. An explicit conversion exists (are you missing a cast?)

Also:

return new RedisConfiguration()

is highlighted.

How do I resolve this?

>Solution :

The error is telling you that the function is returning a RedisConfiguration but it’s expecting to return an IEnumerable<RedisConfiguration>. An apple is not a basket of apples.

Return a collection instead:

return new List<RedisConfiguration> { new RedisConfiguration() };