export default function createDraftAutosave(initialDraft = ''){
  let draft = initialDraft;

  return {
    setDraft(nextDraft){
      draft = nextDraft;
    },
    install(register, save){
      const snapshot = draft;
      return register(() => save(snapshot));
    }
  };
}

import createDraftAutosave from './js-debug-stale-closure-autosave';

describe('createDraftAutosave', () => {
  test('uses the latest draft when the delayed callback finally runs', () => {
    const autosave = createDraftAutosave('hel');
    const saved = [];
    let flush;

    autosave.install((cb) => {
      flush = cb;
      return 'registered';
    }, (value) => {
      saved.push(value);
      return value;
    });

    autosave.setDraft('hello');
    flush();

    expect(saved).toEqual(['hello']);
  });

  test('keeps reading fresh draft values across repeated delayed runs', () => {
    const autosave = createDraftAutosave('a');
    const saved = [];
    let flush;

    autosave.install((cb) => {
      flush = cb;
    }, (value) => {
      saved.push(value);
      return value;
    });

    autosave.setDraft('ab');
    flush();
    autosave.setDraft('abc');
    flush();

    expect(saved).toEqual(['ab', 'abc']);
  });

  test('still works if the draft never changes after install', () => {
    const autosave = createDraftAutosave('draft one');
    let flush;

    autosave.install((cb) => {
      flush = cb;
    }, (value) => value);

    expect(flush()).toBe('draft one');
  });
});