Question

我尝试使用Mocha＆amp; amp ;;对NodeJ进行单元测试。柴...

我的第一个测试套件是根据参数类型验证构造函数是否返回或不返回TypeError。

/* ./test/entity/Point.js */

"use strict";

var expect = require("chai").expect;
var Point = require("./../entity/Point");

describe("Point entity", function() {
    it("x parameter must not be string", function() {
        var fn = function() { var p = new Point("5", 40); };
        expect(fn).to.throw(TypeError);
    });

    it("y parameter must not be string", function() {
        var fn = function() { var p = new Point(5, "40"); };
        expect(fn).to.throw(TypeError);
    });

    it("x and y parameters must be number", function() {
        var fn = function() { var p = new Point(5, 40); };
        expect(fn).to.not.throw(TypeError);
    });
});

我测试的构造函数：

/*./entity/Point.js */

"use strict";

function Point(x, y) {
    // Type validation
    if(x && !(typeof x === "number")) {
        throw new TypeError("x is expected to be a number");
    }
    if(y && !(typeof y === "number")) {
        throw new TypeError("y is expected to be a number");
    }

    // instantiation
    this.x = x;
    this.y = y;
}

module.exports = Point;

第一次测试没问题。第二次测试没问题。但是第三次测试给我发了一个奇怪的断言错误：

  Point entity
    V x parameter must not be string
    V y parameter must not be string
    1) x and y parameters must be number


  2 passing (67ms)
  1 failing

  1) Point entity x and y parameters must be number:
     AssertionError: expected [Function] to not throw 'TypeError' but 'TypeError: Point is not a function' was thrown

      at Context. (C:\Users\Cedric\Documents\NodeProjects\SqueezeParking\test\entity\Point.js:19:32)
      at callFn (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runnable.js:326:21)
      at Test.Runnable.run (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runnable.js:319:7)
      at Runner.runTest (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:422:10)
      at C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:528:12
      at next (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:342:14)
      at C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:352:7
      at next (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:284:14)
      at Immediate._onImmediate (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:320:5)

如果我使用NodeJs断言模块而不是Chai，我也会得到一个断言错误：

  Point entity
    V x parameter must not be string
    V y parameter must not be string
    1) x and y parameters must be number


  2 passing (55ms)
  1 failing

  1) Point entity x and y parameters must be number:
     AssertionError: Got unwanted exception (TypeError)..
      at _throws (assert.js:341:5)
      at Function.assert.doesNotThrow (assert.js:359:3)
      at Context. (C:\Users\Cedric\Documents\NodeProjects\SqueezeParking\test\entity\Point.js:19:16)
      at callFn (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runnable.js:326:21)
      at Test.Runnable.run (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runnable.js:319:7)
      at Runner.runTest (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:422:10)
      at C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:528:12
      at next (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:342:14)
      at C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:352:7
      at next (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:284:14)
      at Immediate._onImmediate (C:\Users\Cedric\AppData\Roaming\npm\node_modules\mocha\lib\runner.js:320:5)

如果我在Mocha之外使用Chai或NodeJs断言模块，第三个测试不会抛出TypeError：

/*./server.js */

var expect = require("chai").expect;
var Point = require("./entity/Point");
var fn = function() {
    var p = new Point(10, 20);
}
expect(fn).to.not.throw(TypeError);

似乎这个奇怪的TypeError来自摩卡，但我不明白为什么以及如何...... 有人有想法吗？

Answer 1

您的测试代码将自身导入为模块。为了说明，请在./test/entity/Point.js的开头将代码更改为：

exports.foo = "foo";
var expect = require("chai").expect;
var Point = require("./../entity/Point");
console.log(Point);

您将获得输出：

{ foo: 'foo' }
[... followed by the tests passing and failing ...]

更改您使用的路径，要求您要测试的代码为var Point = require("../../entity/Point");，测试将通过。

Mocha / Chai to.not.throw（TypeError）奇怪的行为

1 个答案: