Usage of generics with httpsCallable functions

[nthonymiller]

From the documentation the callable functions as per below:

const functions = getFunctions(firebaseApp);
const addMessage = httpsCallable(functions, 'addMessage');
addMessage({ text: messageText })
  .then((result) => ....)

Usage of generics would help with the function signature:

interface AddMessageRequest {
   text: string;
}

const functions = getFunctions(firebaseApp);
const addMessage = httpsCallable<AddMessageRequest>(functions, 'addMessage');
addMessage({ text: messageText })
  .then((result) => {

The response could also typed as well.

[Feiyang1]

Thanks for the feedback! It seems to be the right thing to do. @hsubox76 What do you think?

[mbleigh]

IIRC the response has a mandatory {data: {}} wrapper around it, so I think a request/response two-type generic is most appropriate. That way the actual response signature can be Promise<{data: T}>

[hsubox76]

PR: #4466

[clytras]

Why I can't seem to find this PR changes any more?
Is there any refactoring that removed the httpsCallable generic typings from the repo?

[hsubox76]

No? The PR was made before we launched v9 and made the modular API the default packages. Basically, all the directories that end with "-exp" are now just the same name without the "-exp". For example, the file api.ts from that PR is here: https://github.com/firebase/firebase-js-sdk/blob/master/packages/functions/src/api.ts

If you're seeing a problem with the types, please file an issue, those will get a faster response.

If you just wanted to see the typings for reference, our reference docs are probably the best place to go: https://firebase.google.com/docs/reference/js/functions.md#httpscallable

[clytras]

Thank you for the response @hsubox76.

I was looking for the httpsCallable for another Firebase SDK library for React Native; on a related issue there about httpsCallable types implementation, there was a claim that the Firebase JS SDK httpsCallable does not support generic typings.

Now it's clear to me that it does support generic types, and I can discuss with the maintainers the implementation of the httpsCallable typings on that particular library.