javascript - 在流程 : test whether variables got set 中编写规范

Question

我有以下规范，其中 somePromise() 返回 true 或抛出错误:

describe('context level 1', () => {
  let a;
  let error;

  beforeEach(async () => {
    a = undefined;
    error = undefined;

    try {
      a = await somePromise();
    } catch (e) {
      error = e;
    }
  });

  afterEach(() => {
    a = null;
    error = null;
  });


  describe('context level 2', () => {
    before(() => {
      doSomeSetup();
    });

    it('test case 1', () => {
      a.should.balahalah();
    });
  });

  describe('context level 2', () => {
    before(() => {
      doSomeSetup();
    });

    it('test case 2', () => {
      error.message.should.equal('xxxdasfsda');
    });
  });
});

规范按预期工作，但流检查(我的项目使用 facebook 流)显示如下错误:

Cannot get error.message because property message is missing in null [1].

问题:这些specs应该怎么写成flow？

Answer 1

您可以显式处理所有可能的场景以避免流程错误。

describe('context level 1', () => {
  describe('context level 2', () => {
    before(() => {
      doSomeSetup();
    });

    it('test case 1', () => {
      try {
        const a = await subject();
        should(result).balahalah();
      } catch (e) {
        should.not.exist(e);
      }
    });
  });

  describe('context level 2', () => {
    before(() => {
      doSomeSetup();
    });

    it('test case 2', () => {
      try {
        const a = await subject();
        should.not.exist(a);
      } catch (e) {
        e.message.should.equal('xxxdasfsda');
      }
    });
  });
});