Message context apps are broken for user-only installs

[VelvetToroyashi]

Description

The current message parser attempts to make a GET request for the message despite all information being present in the interaction (in fact, GW data can be more beneficial than REST, so this is even more moot)

Steps to Reproduce

Create an application
Enable user install
Authorize the application to your account
Create a command which is usable by user-install (default)
Run said command

Expected Behavior

The application responds

Current Behavior

The application does not respond (because Remora cannot parse the data, because the request that it should not be making fails)

Library / Runtime Information

2025.2.0

[VelvetToroyashi]

The offending line is here:

Remora.Discord/Remora.Discord.Commands/Parsers/MessageParser.cs

Line 78 in 03e93b8

return await _channelAPI.GetChannelMessageAsync(channelID, messageID.Value, ct);

The parser should attempt to pull from an interaction context if it exists, as that will have a populated message in the resolved which may be relevant, but fall back for message commands.

My personal implementation could be cleaned up, but:

public class ContextAwareMessageParser
(
    IOperationContext context, 
    ITypeParser<IMessage> fallback
) : AbstractTypeParser<IPartialMessage>
{
    public async override ValueTask<Result<IPartialMessage>> TryParseAsync(string token, CancellationToken ct)
    {
        if (!DiscordSnowflake.TryParse(token, out Snowflake? mid))
        {
            return new ParsingError<IPartialMessage>("Invalid snowflake");
        }
        
        Snowflake messageID = mid.Value; 
        
        // "Context-aware"; attempt to pull from the interaction, if available, and if it hasn't already been parsed
        if 
        (
            context is InteractionContext
            {
                Interaction.Data: { HasValue: true, Value.Value: IApplicationCommandData data }
            } &&
            data.Resolved.Value.Messages.Value.TryGetValue(messageID, out IPartialMessage? message)
        )
        {
            return Result<IPartialMessage>.FromSuccess(message);
        }

        Result<IMessage> fallbackResult = await fallback.TryParseAsync(token, ct);
        return fallbackResult.Map(parsed => (IPartialMessage) parsed);
    }
}

[MazeXP]

Is your command relying on IMessage or IPartialMessage?
If the later then the current PartialMessageParser should already have this functionality implemented and it is not being used at all in your case.