Run npm run graphql:validate to validate all the documents (queries, mutations and fragments)
As graphql is strongly typed, the typescript client application needs to update the models everytime it changes.
Run npm run graphql:generate to generates the typescript types, download the schema and generate the fragment matchers.
If the models has changed, the first step is te check if our documents needs to be updated (cf Documents validation).
If the validation fails, then run npm run graphql:diff to compare the schema downloaded during the last model generation with the actual schema.
Run npm run graphql:coverage to find out how many times types and fields are used in your application.
https://apis.guru/graphql-voyager/ allow you to paste your schema and get a visual representation.
For testing purpose there is an easy way to start a fake server. Simply run npm run graphql:serve