My configuration:

    'graphql/required-fields': [
      'error',
      {
        env: 'apollo',
        schemaJson: require('./schema.json'),
        requiredFields: ['id'],
      },
      {
        env: 'literal',
        schemaJson: require('./schema.json'),
        requiredFields: ['id'],
      },
    ],

My query:

query Main {
  nestedField {
    ...NestedField
  }
}

fragment NestedField on SomeType {
  id
  someField
}

Expected result

No linter error.

Actual result

/path/MyQuery.graphql
  2:3  error  'id' field required on 'nestedField'  graphql/required-fields

Apparently the required-fields rule doesn't account for fields included in a fragment.

Update

It seems like field selection merging is part of the GraphQL specification: https://graphql.github.io/graphql-spec/draft/#sec-Field-Selection-Merging

So this is not really a bug per se but more a feature request to be more exhaustive in checking for the inclusion of required fiels in fragments.