NonNullable utility type | discord.js - imagine an app | Page 1

wind hull Dec 20, 2023, 4:00 AM

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@warm knoll

ebon rockBOT Dec 20, 2023, 4:00 AM

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Consider reading #how-to-get-help to improve your question!
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warm knoll Dec 20, 2023, 4:00 AM

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For anyone else reading and wanting context: #djs-help-v14 message

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I suggest giving this a decent look at first so you know what I'm actually talking about
https://www.typescriptlang.org/docs/handbook/utility-types.html#nonnullabletype

wind hull Dec 20, 2023, 4:01 AM

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makes a lot of sense

warm knoll Dec 20, 2023, 4:02 AM

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Right, so you'd want to make an interface that extends the d.js ChatInputCommandinteraction

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And in that interface, you define a channel property, and the type of that property is the NonNullable type of the ChatInputCommandInteraction.channel

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All you're doing in this process is replacing the type of the channel property with exactly what it is, but excluding null

wind hull Dec 20, 2023, 4:03 AM

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import type { ChatInputCommandInteraction } from "discord.js";

export interface ExtendedChatInputCommandInteraction extends ChatInputCommandInteraction {
  channel: NonNullable<ChatInputCommandInteraction.channel>
}

like this?

warm knoll Dec 20, 2023, 4:04 AM

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Just about, yea. I'd add the CacheType ~~enum~~ generic (probably "cached" for you) there as well if needed

wind hull Dec 20, 2023, 4:04 AM

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what will that do

warm knoll Dec 20, 2023, 4:05 AM

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Ensure that some properties of the interaction are cached. Of course, this is useless if you don't have your runtime checks beforehand in your command handler (e.g. inCachedGuild() like some have suggested to you)

wind hull Dec 20, 2023, 4:06 AM

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ah so adding "cached" then doing the caching checks will be good too?

warm knoll Dec 20, 2023, 4:07 AM

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Yes. That makes you dialed both on the type level and runtime level

wind hull Dec 20, 2023, 4:07 AM

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warm knoll Just about, yea. I'd add the CacheType ~~enum~~ generic (probably `"cached"` for...

how would i do this?

warm knoll Dec 20, 2023, 4:07 AM

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Sorry - just realized - not enum, generic

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interface ... extends ChatInputCommandInteraction<"cached">

wind hull Dec 20, 2023, 4:09 AM

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warm knoll Dec 20, 2023, 4:09 AM

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This is what I did for my project, if you'd like a - in my opinion - good reference

warm knoll Dec 20, 2023, 4:09 AM

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wind hull

Can you show what you typed channel as behind that hover window?

wind hull Dec 20, 2023, 4:10 AM

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channel: NonNullable<ChatInputCommandInteraction["channel"]>

warm knoll Dec 20, 2023, 4:10 AM

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Yea, you forgot to add the <"cached"> generic to there as well

wind hull Dec 20, 2023, 4:11 AM

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ohhh

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that fixes everything, so i just do the same thing for other commands if it's not a chat input command? e.g. context menus

warm knoll Dec 20, 2023, 4:12 AM

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You could, assuming you do your proper runtime checking beforehand there as well

wind hull Dec 20, 2023, 4:12 AM

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okay can you remind me of the checks i must do

warm knoll Dec 20, 2023, 4:13 AM

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Well, moreless just as what you detailed in #djs-help-v14 - checking if interaction.channel is null

wind hull Dec 20, 2023, 4:14 AM

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and checking interaction.inCachedGuild()?

warm knoll Dec 20, 2023, 4:14 AM

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Right, yea, that for member/guild-related data for the associated interaction

wind hull Dec 20, 2023, 4:15 AM

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alr

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what do you recommend i name my ExtendedChatInputCommandInteraction

warm knoll Dec 20, 2023, 4:17 AM

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Really up to you. I just prefix my interaction/client extensions with a T for the first letter of my username to denote that I made it, followed by whatever it is, TInteraction in this case

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Although I don't fully suggest using that naming scheme for your slash command interaction extension, as {prefix}Interaction is a bit vague since there's multiple different kinds of interactions

wind hull Dec 20, 2023, 4:20 AM

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tysm man you've been a MASSIVE help, sorry about being difficult

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also i moved all my typings to typings.ts, do you recommend .ts or .d.ts?

warm knoll Dec 20, 2023, 4:22 AM

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That's something I don't have full knowledge on, so if you want a solid answer, I'd wait for if someone else more knowledgeable in TS would want to chime in

wind hull Dec 20, 2023, 4:22 AM

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alr

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oh one last thing

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warm knoll Dec 20, 2023, 4:23 AM

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Is this run() function part of a class?

wind hull Dec 20, 2023, 4:24 AM

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ohhh i see

warm knoll Dec 20, 2023, 4:24 AM

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Looks like it

wind hull Dec 20, 2023, 4:24 AM

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hmmmm now im getting this

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if(interaction.isChatInputCommand()) {
   if(!interaction.channel || !interaction.inCachedGuild()) return;

   command.run(interaction);
}

warm knoll Dec 20, 2023, 4:25 AM

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Yea, I think that's a shortcoming of that, as I can't think of an easy and safe way to have them play nicely if you're using classes for your commands

wind hull Dec 20, 2023, 4:26 AM

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im just doing this ```ts
export interface Command {
name?: string; // Optional as not explicitly given in command files
description: string;
type: ApplicationCommandType;
options?: ApplicationCommandOptionData[];
run: (interaction: ECICInteraction) => Promise<void>;
autocomplete?: (interaction: AutocompleteInteraction) => Promise<void>;
}

warm knoll Dec 20, 2023, 4:29 AM

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Yea you might have to make some compromises, not totally sure with that one. It works for me because my command file types are cut off when they exit the command files into my command handler. You seem to be constraining your command files to that Command interface which is what your command files also use

wind hull Dec 20, 2023, 4:30 AM

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are cut off when they exit the command files
wdym by this? do you have a ref

warm knoll Dec 20, 2023, 4:30 AM

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I don't constrain my command file exports to an Interface like you do

wind hull Dec 20, 2023, 4:31 AM

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ah

warm knoll Dec 20, 2023, 4:31 AM

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I'm just exporting them as they are

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Which does work for me, however can be a bit risky during runtime if you don't format your command file properly and don't realize

wind hull Dec 20, 2023, 4:31 AM

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yeah

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doing command.run(interaction as ECICInteraction); fixed it

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is that a good idea?

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warm knoll Dec 20, 2023, 4:34 AM

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Well, with you doing your runtime checking above it, I don't really see a reason for it to not be safe. Type casting should really be a last resort, and it does seem like this might be a case where you would otherwise be stuck in a tight corner with type errors. I can't think of a better way to do this, so it seems to me like that'd be your best bet there

wind hull Dec 20, 2023, 4:34 AM

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alr tysm

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its 5am so im gonna sleep now aha

warm knoll Dec 20, 2023, 4:35 AM

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Have a good one

wind hull Dec 20, 2023, 4:35 AM

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you too<3

unreal obsidian Dec 20, 2023, 6:53 AM

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wind hull is that a good idea?

Make a typeguard yourself

function isECICInteraction(interaction: Interaction): interaction is ECICInteraction {
  return interaction.isChatInputCommand() && interaction.inCachedGuild() && interaction.channel !== null;
}

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Better than an explicit cast, since it couples your runtime checks and the type change so you won‘t cast without checks

#NonNullable utility type