Regression test for loss of data with overlapping fragments in apollo-cache-hermes

apollo-cache-hermes-overlapping-fragments-test.ts

import { GraphSnapshot } from '../../../../../src/GraphSnapshot';
import { createSnapshot } from '../../../../helpers';

describe(`overlapping fragments`, () => {
  let snapshot: GraphSnapshot;
  beforeAll(() => {
    const cyclicRefQuery = `
      query {
        myDetailedBar {
          ...DetailedBarFragment
        }
        myFooOrBar {
          ...FooFragment
          ...BarFragment
        }
      }

      fragment FooFragment on Foo {
        id
        payload
      }

      fragment BarFragment on Bar {
        id
        fizz
      }

      fragment DetailedBarFragment on Bar {
        ...BarFragment
        payload
      }
    `;

    const result = createSnapshot(
      {
        myDetailedBar: {
          id: 'Bar:1',
          fizz: 'buzz',
          payload: 'huge',
        },
        myFooOrBar: {
          id: 'Bar:1',
          fizz: 'buzz',
        },
      },
      cyclicRefQuery
    );

    snapshot = result.snapshot;
  });

  it(`writing an entity with overlapping fragment fields should not lose data`, () => {
    const bar = snapshot.getNodeData('Bar:1');

    expect(bar.id).to.eq('Bar:1');
    expect(bar.fizz).to.eq('buzz');
    expect(bar.payload).to.eq('huge');
  });
});