Function createSyncCollection

packages/db/tests/query/includes.test.ts:6299–6331

(
      id: string,
      getKey: (item: T) => string | number,
    )

  describe(`many sibling toArray includes with chained derived collections`, () => {
    function createSyncCollection<T extends object>(
      id: string,
      getKey: (item: T) => string | number,
    ) {
      let syncBegin: () => void
      let syncWrite: (msg: { type: string; value: T }) => void
      let syncCommit: () => void

      const collection = createCollection<T>({
        id,
        getKey,
        sync: {
          sync: (params: any) => {
            syncBegin = params.begin
            syncWrite = params.write
            syncCommit = params.commit
            params.markReady()
            return () => {}
          },
        } as SyncConfig<T>,
        startSync: true,
        gcTime: 0,
      })

      return {
        collection,
        insert(value: T) {
          syncBegin!()
          syncWrite!({ type: `insert`, value })
          syncCommit!()
        },
      }
    }

    const TIMELINE_KEY = `timeline`