@apollo/federation/src/composition/validate/preComposition/__tests__/externalUsedOnBase.test.ts

Apollo Federation Utilities

import { externalUsedOnBase as validateExternalUsedOnBase } from '../';
import {
  gql,
  graphqlErrorSerializer,
} from 'apollo-federation-integration-testsuite';

expect.addSnapshotSerializer(graphqlErrorSerializer);

describe('externalUsedOnBase', () => {
  it('does not warn when no externals directives are defined', () => {
    const serviceA = {
      typeDefs: gql`
        type Product @key(fields: "color { id value }") {
          sku: String!
          upc: String!
          color: Color!
        }

        type Color {
          id: ID!
          value: String!
        }
      `,
      name: 'serviceA',
    };

    const warnings = validateExternalUsedOnBase(serviceA);
    expect(warnings).toEqual([]);
  });

  it('warns when there is a @external field on a base type', () => {
    const serviceA = {
      typeDefs: gql`
        type Product @key(fields: "sku") {
          sku: String!
          upc: String! @external
          id: ID!
        }
      `,
      name: 'serviceA',
    };

    const warnings = validateExternalUsedOnBase(serviceA);
    expect(warnings).toMatchInlineSnapshot(`
      Array [
        Object {
          "code": "EXTERNAL_USED_ON_BASE",
          "locations": Array [
            Object {
              "column": 16,
              "line": 4,
            },
          ],
          "message": "[serviceA] Product.upc -> Found extraneous @external directive. @external cannot be used on base types.",
        },
      ]
    `);
  });
});