What is the proper way to pass something into slash command handler?

[telephrag]

I'm interacting with mongodb inside handlers and need pointer to collection inside database.

[FedorLap2006]

I think dependency injection is what you need.
In Go you can implement it using structs and methods. Like that:

type MyAppOrModule struct {
     Client *Something
}

func (m *MyAppOrModule) HandleSlash(s *discordgo.Session, i *discordgo.InteractionCreate) {
     m.Client.DoSomething(...)
}

[telephrag]

var HandlerToCmd = map[string]func(s *discordgo.Session, i *discordgo.InteractionCreate){
    "command": nil,
    // other commands...
}

type MongoSession struct {
    Client     *mongo.Client
    Collection *mongo.Collection
}

func New(args) *MongoSession {
    ms := &MongoSession{
        // ...
    }

    HandlerToCmd["command"] = (ms).Command
    // assigning other methods to map...
}

func DoSmtWithDb(i *discordgo.InteractionCreate, ms* MongoSession) {
    // ...
}

func (ms *MongoSession) Command(s *discordgo.Session, i *discordgo.InteractionCreate) {
    // do stuff...
    DoSmtWithDb(i, ms)
}

This is what I ended up with. It works but can it be made simpler? It used to be just global variable that pointed to MongoSession object.

[FedorLap2006]

I would recommend renaming it to Module or Instance / <BotName>, that's the general approach for that.
Additionally, I think would be better to move all the logic inside the handler.
But if you're going with "Clean Architecture" approach, you can make services and repositories which will take care of the storage and business logic, leaving handlers only to work with input and output.

[telephrag]

Thank you.