Provide Spectre.Console.Cli.CommandSettings as Interface

[BigPapa314]

Context

I'm implementing a CLI app that shares some configuration settings among multiple different commands. One example is the output specification (file name or STDOUT). I'd like to create a separate ComandSettings class for just the output setting so that I can write some code like:

if (settings is OutputSettings outputSettings) {
    appContext.Ouput = File.Open(outputSettings.Output);
}

I also have some other command line settings that occur multiple times like DatabaseSettings, LoggingSettings, ....

The different commands whould need to compose these settings as they need. Like

public class ListDatabaseSettings : LoggingSettings, OutputSettings
{
}
public class ReadDatabaseSettings : LoggingSettings, OutputSettings, DatabaseConnectionSettings, DatabaseKeySettings
{
}
public class WriteDatabaseSettings : LoggingSettings, DatabaseConnectionSettings, DatabaseKeySettings
{
    [Description("The value to write to the database.")]
    [CommandOption("-v|--value")]
    public string Value { get; init; }
}

This does not work because C# is only able to derive from one base class.

Possible Solution

If the settings could be a C# Interfaces like in commandline then it would be possible to inherit from multiple Interfaces and compose the command line parameters more freely. A possible drawback is that the final classes have to implement the interfaces.

public interface IOutputSettings {
    [Description("The output to store the result.")]
    [CommandOption("-o|--output")]
    public string? Output { get; init; }
}

public class ListDatabaseSettings : ComandSettings, ILoggingSettings, IOutputSettings 
{
    public string? LogLevel { get; init; }
    public string? Output { get; init; }
}
public class ReadDatabaseSettings : ComandSettings, ILoggingSettings, IOutputSettings, IDatabaseConnectionSettings, IDatabaseKeySettings
{
    public string? LogLevel { get; init; }
    public string? Output { get; init; }
    public string DatabaseUrl { get; init; }
    public string Key { get; init; }
}
public class WriteDatabaseSettings : ComandSettings, ILoggingSettings, IDatabaseConnectionSettings, IDatabaseKeySettings
{
    public string? LogLevel { get; init; }
    public string DatabaseUrl { get; init; }
    public string Key { get; init; }

    [Description("The value to write to the database.")]
    [CommandOption("-v|--value")]
    public string Value { get; init; }
}

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