feat: Add indexes to Entity for improved performance

[ntucker]

Fixes #232.

Motivation

Sometimes you want to request data via different parameters.
Say you have user data. It has both an id and a username. When someone visits their profile you want to have the url have the username. Thus it would be best to look it up via that username. So you add an endpoint that supports that.

const user = useResource(UserResource.detailShape(), { username: 'bob' });

Unfortunately, because username is not the primary key, this cannot be inferred from entity cache alone. This means if we visited a user list page, then went to that user's profile page - we would have to wait while the new request finishes. This is quite silly, as a request with the primary key would instantly resolve (one of the unique benefits of Rest Hooks).

Solution

export class UserResource extends Resource {
  readonly id: number | undefined = undefined;
  readonly username: string = '';
  readonly email: string = '';
  readonly isAdmin: boolean = false;

  pk() {
    return this.id?.toString();
  }

  static urlRoot = 'http://test.com/user/';

  static indexes = ['username'];
}

Now you can:

const user = useResource(UserResource.detailShape(), { username: 'bob' });

And get results before the fetch completes!

Note: Inferred results are always considered stale and will revalidate when useResource().

[kmartinezmedia]

🚀