如何对 node-cron 作业进行单元测试

Question

我需要使用 node-cron 调用一个函数，并想为此编写一个单元测试用例。单元测试用例应该能够测试函数是否正在根据模式进行调用。

下面是我的代码

const server = (module.exports = {
  cronJob: null,
  scheduledJob: function(pattern) {
    server.cronJob = cron.schedule(pattern, () => {
      server.run();
    });
  },
  run: function() {
    console.log("run called");
  },
}); 

describe("entry point test suite", () => {
  it("should call function every second", (done) => {
    const pattern = "* * * * * *";
    let spy = sinon.spy(server, "run");
    server.scheduledJob(pattern);
    server.cronJob.Start();
    // to do wait for 3 sencond
    server.cronJob.Stop();
    expect(spy.callCount).eq(3);
  });
}); 

两个问题：

1. 除了setTimeout我必须等待 3 秒的选项之外，cron 作业将按照模式每秒运行 3 次。

2. 此测试失败，错误为 server.cronjob.start is not a function。

我怎样才能使这项工作？

Answer 1

这是单元测试解决方案：

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server.js:

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const cron = require("node-cron");\n\nconst server = (module.exports = {\n  cronJob: null,\n  scheduledJob: function(pattern) {\n    server.cronJob = cron.schedule(pattern, () => {\n      server.run();\n    });\n  },\n  run: function() {\n    console.log("run called");\n  },\n});\n

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server.test.js:

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const server = require("./server");\nconst sinon = require("sinon");\nconst cron = require("node-cron");\nconst { expect } = require("chai");\n\ndescribe("57208090", () => {\n  afterEach(() => {\n    sinon.restore();\n  });\n  describe("#scheduledJob", () => {\n    it("should schedule job", () => {\n      const pattern = "* * * * * *";\n      const runStub = sinon.stub(server, "run");\n      const scheduleStub = sinon\n        .stub(cron, "schedule")\n        .yields()\n        .returns({});\n      server.scheduledJob(pattern);\n      sinon.assert.calledWith(scheduleStub, pattern, sinon.match.func);\n      sinon.assert.calledOnce(runStub);\n      expect(server.cronJob).to.be.eql({});\n    });\n  });\n\n  describe("#run", () => {\n    it("should run server", () => {\n      const logSpy = sinon.spy(console, "log");\n      server.run();\n      sinon.assert.calledWith(logSpy, "run called");\n    });\n  });\n});\n

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100%覆盖率的单元测试结果：

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  57208090\n    #scheduledJob\n      \xe2\x9c\x93 should schedule job\n    #run\nrun called\n      \xe2\x9c\x93 should run server\n\n\n  2 passing (12ms)\n\n----------------|----------|----------|----------|----------|-------------------|\nFile            |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |\n----------------|----------|----------|----------|----------|-------------------|\nAll files       |      100 |      100 |      100 |      100 |                   |\n server.js      |      100 |      100 |      100 |      100 |                   |\n server.test.js |      100 |      100 |      100 |      100 |                   |\n----------------|----------|----------|----------|----------|-------------------|\n

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您要求进行单元测试。如果您需要集成测试，请创建一个新帖子。

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源代码：https ://github.com/mrdulin/mocha-chai-sinon-codelab/tree/master/src/stackoverflow/57208090

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