Improve error handling by adding types for Octokit error

[sorenlouv]

Hi there,

I'm trying to handle the errors from Octokit but I'm not able to find docs (or better: types) for the errors that can be thrown.
As an example, this is how I hoped I'd be able to get a typed error:

try {
    const octokit = new Octokit(...);
    return await octokit.search.commits(...);
} catch(e) {
  if(e instanceof OctokitError) {
    // `e` will now be typed
  }
}

But I can't find anything like OctokitError in the types. I can add my own error type like:

type OctokitError = {
  name: string;
  status: number;
  documentation_url: string;
  errors?: Array<{
    resource: string;
    code: string;
    field: string;
    message?: string;
  }>;
};

Is there a concrete contract for errors I can see somewhere to ensure above type is correct? I looked in the docs and they seem incorrect (or out of date):

See for example this error I got back from octokit.search.commits:

Notice how there is a message in: e.errors[i].message where the docs only mentions e.message.

[gr2m]

We could add an OctokitRequestError type to https://github.com/octokit/types.ts/tree/master/src, so you can import it from @octokit/types.

I don't think it's currently possible to set types for errors that can be thrown by a method (microsoft/TypeScript#13219), that'd be cool though

[sorenlouv]

I don't think it's currently possible to set types for errors that can be thrown by a method (microsoft/TypeScript#13219), that'd be cool though

yeah, that would be neat. But until then I think if(e instanceof OctokitRequestError) is the recommended approach. Having an explicit type like OctokitRequestError will be great for documentation purposes also.

[gr2m]

could you send a pull request to https://github.com/octokit/types.ts/?

[sorenlouv]

@gr2m Done!