Types of function context and arguments

let's say I want to create a utility function that does a query inside a function like this:

async function loadGame(db, id) {
  const game = (await db
    .query("games")
    .filter((q) => q.eq(q.field("_id"), id))
    .unique()) ?? raise(`Game with id ${id} doesn't exist.`);
  return game ;
}

async function loadGame(db, id) {
  const game = (await db
    .query("games")
    .filter((q) => q.eq(q.field("_id"), id))
    .unique()) ?? raise(`Game with id ${id} doesn't exist.`);
  return game ;
}

what's the correct typing on db and id?

12 Replies

Michal Srb•2y ago

You can go to the definition of query to see the context type. You can either use QueryCtx for the whole context type or DatabaseReader just for the db. IDs will be Id<"tableName"> exported from _generated/server. Feel free to post in the support channel with concrete questions, might be easier for other folks to find later.

cyremurOP•2y ago

Oh yeah sorry

Michal Srb•2y ago

No worries! Keep the feedback coming, we love it. This is a good question, and we should have better docs here (right now it only mentions the ID type): https://docs.convex.dev/typescript

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lee•2y ago

btw your loadGame function might be easier to write with db.get(id) (drive by comment, feel free to ignore 😛 )

cyremurOP•2y ago

oh yeah I had a legacy id field from my previous stack and then switched out to native convex ids yesterday and just went from id to _id

cyremurOP•2y ago

but yeah reason for this question is

cyremurOP•2y ago

like vscode just tries to vomit the whole schema into the tooltip and I'm like... but what do I write as function arg type?

Michal Srb•2y ago

Yeah, definitely not obvious! import {DatabaseWriter} from './_generated/server'

cyremurOP•2y ago

My idea comes from client side though and currently comes in as args.id : v.string() Do I typecast that for db.get(id) or how can I make the function validate game ids? nvm rtfm

lee•2y ago

i would type it as v.id("games") and do the cast client-side if necessary that way the server can validate that the id is actually valid and in the "games" table (otherwise, if you cast server-side, a rogue client could use this to get any document)

cyremurOP•2y ago

I just hand the raw document row to the client with _id type as is is that bad practice?

lee•2y ago

sounds fine to me 🙂

Types of function context and arguments

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