Node js 单元测试 sinon chai

Question

如何为下面的文件创建单元测试

index.ts

import ----
import ----

let workerService = new WorkerService();
let creatWorkerPromise = Promise.promisify(workerService.createWorkers);

creatWorkerPromise()
.then(function(){
    let kafkaService =  new KafkaService(kafkaConfig, workerService);
})
.catch(function (err: any) {
    console.log('Error while creating workers:', err);
});

Answer 1

测试不是单元的东西有点困难，因为单元通常会公开要测试的方法，所以我假设您最终会在测试代码中执行此操作。所以这里是：

///////////
// index.js
///////////
// stubs for this example to work
var createWorkerPromise = function(){ return Promise.resolve(); }
var workerService, kafkaConfig;
function KafkaService(){ throw new Error("crashes test"); }

function exportedFunction(){ 
  return createWorkerPromise()
    .then(function(){
        var kafkaService =  new KafkaService(kafkaConfig, workerService);
    })
    .catch(function (err) {
        console.log('Error while creating workers:', err);
    });
}

///////////
// test.js
///////////
var log = console.log.bind(console);
var assert = function(expr) {
  if(!expr) throw new Error("AssertionError"); 
  log("TEST OK");
}

// the test
var spy = sinon.spy(console, 'log');
exportedFunction().then(function test() {
  assert(spy.called);
  
}).catch(log.bind(null, "TEST FAILED"))

<script src="https://unpkg.com/sinon@latest/pkg/sinon.js"></script>