Exemplo de código JS para realizar várias chamadas assíncronas para API backend utilizando iterables e for await...of

getGitLabIssuesByMilestone.js

const fetchAllResources = async (resources, params) => {
  const asyncIterable = {
    [Symbol.asyncIterator]() {
      return {
        page: '1',
        finished: false,
        async next() {
          if (!this.finished) {
            const response = await api.get(resources, {
              params: { ...params, page: this.page },
            });

            const nextPage = response.headers['x-next-page'] || '';

            this.finished = nextPage === '';
            this.page = nextPage;

            return Promise.resolve({
              value: response,
              done: false,
            });
          }

          this.page = '1';
          this.finished = false;

          return Promise.resolve({
            done: true,
          });
        },
      };
    },
  };

  let results = [];

  for await (const resp of asyncIterable) {
    const { data } = resp;
    results = [...results, ...data];
  }

  return results;
};

export const getAllIssues = async milestone => {
  const params = {
    milestone,
    per_page: 100,
    scope: 'all',
    sort: 'asc',
  };

  return fetchAllResources('issues', params);
};