return type of auth({ type: "installation", installationId, factory }) should be Promise<ReturnType<factory>>

[gr2m]

Follow up to https://github.com/octokit/auth-app.js/pull/198/files#diff-c54113cf61ec99691748a3890bfbeb00e10efb3f0a76f03a0fd9ec49072e410aR109-R111

Currently, when doing this:

const AppOctokit = Octokit.defaults({ authStrategy: createAppAuth, });
const appOctokit = new AppOctokit({
  auth: {
    id: APP_ID,
    privateKey: PRIVATE_KEY,
  },
});

const installationOctokit = await appOctokit.auth({
  type: "installation",
  installationId: INSTALLATION_ID,
  factory: (auth) => new appOctokit.constructor({ auth }),
});

The type for installationOctokit is unknown. What it should be though is the same as the type of appOctokit.

With the way the Types for authentication strategies are currently implemented, this change will be very hard to accomplish. Unfortunately it will be quite a rabbit hole, but I think it's about time we introduce a globally declared Octokit namespace on which we can define interfaces that plugins and users can extend.

I'd declare the global Octokit namespace in https://github.com/octokit/types.ts/

declare namespace Octokit {
    export interface AuthenticationStrategies {}
}

Then each Octokit authentication strategy module could extend the interface

declare namespace Octokit {
    export interface AuthenticationStrategies {
      OctokitApp: {
        authStrategy: Strategy;
        auth: AuthOptions;
      }
    }
}

We could still use OctokitTypes.StrategyInterface with implements to make sure the API surface for each authentication strategy is compatible.

See

• https://github.com/octokit/rest.js/issues/1562#issuecomment-582678977
• [discussion]: Put foundations on Octokit namespace webhooks.js#308

[github-actions]

🎉 This issue has been resolved in version 3.5.2 🎉

The release is available on:

• GitHub release
• npm package (@latest dist-tag)

Your semantic-release bot 📦🚀