GraphQL.md

https://www.apollographql.com/tutorials/lift-off-part2/04-implementing-our-restdatasource

Let's define a constructor method inside the class. Inside, we'll call super() to make sure we get access to our RESTDataSource features. We'll also assign our REST API's base url.

class TrackAPI extends RESTDataSource {
  constructor() {
    super();
    this.baseURL = "https://odyssey-lift-off-rest-api.herokuapp.com/";
  }
}

Note: Be sure that your TrackAPI class' baseURL value ends with a /. This will allow our helper class to make requests and append new paths to the baseURL without any errors.

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https://www.apollographql.com/tutorials/lift-off-part2/05-the-shape-of-a-resolver

A resolver is a function. It has the same name as the field that it populates data for. It can fetch data from any data source, then transforms that data into the shape your client requires.

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https://www.apollographql.com/tutorials/lift-off-part2/08-querying-live-data

The first one took about half a second, then this one returned in just a few milliseconds. This is thanks to our RESTDataSource's built-in resource caching.

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https://www.apollographql.com/tutorials/lift-off-part2/09-errors-when-queries-go-sideways

There could be multiple errors! ApolloServer provides error codes that will help to narrow down what caused the issues.