我有一个猫鼬模型：

var mongoose = require("mongoose");

var transactionSchema = mongoose.Schema({
  category: { type: String, required: [true, "Category is required."] },
  amount: Number,
  comment: String,
  tags: Array,
  currency: String
});

var Transaction = mongoose.model("Transaction", transactionSchema);

module.exports = Transaction;

并使用mockgoose和jest进行简单的单元测试：

var { Mockgoose } = require("mockgoose");
var mongoose = require("mongoose");
var Transaction = require("./transaction");

var mockgoose = new Mockgoose(mongoose);

describe("transaction", function() {
  afterEach(function() {
    mockgoose.helper.reset().then(() => {
      done();
    });
  });

  it("category is required", function() {
    mockgoose.prepareStorage().then(() => {
      mongoose.connect("mongodb://foobar/baz");
      mongoose.connection.on("connected", () => {
        var mockTransaction = new Transaction({
          category: "Transportation",
          amount: 25,
          comment: "Gas money, Petrol.",
          tags: ["Gas", "Car", "Transport"],
          currency: "EUR"
        });
        mockTransaction.save(function(err, savedTransaction) {
          if (err) return console.error(err);
          expect(savedTransaction).toEqual(mockTransaction);
        });
      });
    });
  });
});

现在,当我运行测试时,我收到了以下两个警告：

(node:2199) UnhandledPromiseRejectionWarning: Unhandled promise
rejection (rejection id: 1): ReferenceError: done is not defined
(node:2199) [DEP0018] DeprecationWarning: Unhandled promise rejections
are deprecated. In the future, promise rejections that are not handled
will terminate the Node.js process with a non-zero exit code.

然后单元测试通过,然后我收到此错误消息：

Jest did not exit one second after the test run has completed.

This usually means that there are asynchronous operations that weren’t
stopped in your tests. Consider running Jest with
--detectOpenHandles to troubleshoot this issue.

一旦得到正确的结果,我该如何终止测试？

解决方法:

错误意味着它所说的完全没有定义,但已经使用了.如果使用promises,则不需要它. Jest支持promises,应该从块中返回一个promise以便正确处理：

afterEach(() => mockgoose.helper.reset());

如果在this question中打开句柄出现问题,可以使用以下方式明确断开Mongoose：

afterAll(() => mongoose.disconnect());