import { describe, expect, it } from 'vitest';
import { strayIdsAfterCatchUp } from '../reindex';

describe('strayIdsAfterCatchUp', () => {
  it('removes locally-indexed ids absent from a complete (uncapped) fetch', () => {
    // Contacts/files have no date filter, so a catch-up query that comes back
    // under the cap IS the whole account - anything indexed but missing from
    // it was deleted. This is the only place a JMAP `destroyed` ever reaches
    // these two content types, since nothing in the renderer populates
    // reindex's `removed` field.
    const existing = new Set(['a', 'b', 'c']);
    expect(strayIdsAfterCatchUp(existing, ['a', 'c'], 2, 2_000)).toEqual(['b']);
  });

  it('does nothing when the fetch is empty but so is the local index', () => {
    expect(strayIdsAfterCatchUp(new Set(), [], 0, 2_000)).toEqual([]);
  });

  it('never removes anything when the query hit its cap - a truncated page is not the whole world', () => {
    // Exactly the case that would otherwise delete objects that are still
    // live: an account with >= cap contacts/files, where "missing from this
    // page" only means "not on this page", not "gone".
    const existing = new Set(['a', 'b', 'c']);
    expect(strayIdsAfterCatchUp(existing, ['a'], 2_000, 2_000)).toEqual([]);
  });

  it('is a no-op when nothing is stray', () => {
    const existing = new Set(['a', 'b']);
    expect(strayIdsAfterCatchUp(existing, ['a', 'b', 'c'], 3, 2_000)).toEqual([]);
  });
});