JavaScript 代码没有通过 Jasmine toThrow 测试

Question

我正在学习JavaScript和Jasmine-Node我已经成功通过了前11个匹配器。但是我似乎无法通过这个 toThrow matcher 并且我已经查找了我能想到的一切来通过它。我卡住了。我真的很感激一些帮助，也欢迎对我的代码提出任何意见。

这是规格测试...

var Triangle = require('./triangle');

describe('Triangle', function() {

  it('equilateral triangles have equal sides', function() {
    var triangle = new Triangle(2,2,2);
    expect(triangle.kind()).toEqual('equilateral');
  });

  it('larger equilateral triangles also have equal sides', function() {
    var triangle = new Triangle(10,10,10);
    expect(triangle.kind()).toEqual('equilateral');
  });

  it('isosceles triangles have last two sides equal', function() {
    var triangle = new Triangle(3,4,4);
    expect(triangle.kind()).toEqual('isosceles');
  });

  it('isosceles trianges have first and last sides equal', function() {
    var triangle = new Triangle(4,3,4);
    expect(triangle.kind()).toEqual('isosceles');
  });

  it('isosceles triangles have two first sides equal', function() {
    var triangle = new Triangle(4,4,3);
    expect(triangle.kind()).toEqual('isosceles');
  });

  it('isosceles triangles have in fact exactly two sides equal', function() {
    var triangle = new Triangle(10,10,2);
    expect(triangle.kind()).toEqual('isosceles');
  });

  it('scalene triangles have no equal sides', function() {
    var triangle = new Triangle(3,4,5);
    expect(triangle.kind()).toEqual('scalene');
  });

  it('scalene triangles have no equal sides at a larger scale too', function() {
    var triangle = new Triangle(10,11,12);
    expect(triangle.kind()).toEqual('scalene');
  });

  it('scalene triangles have no equal sides in descending order either', function() {
    var triangle = new Triangle(5,4,2);
    expect(triangle.kind()).toEqual('scalene');
  });

  it('very small triangles are legal', function() {
    var triangle = new Triangle(0.4,0.6,0.3);
    expect(triangle.kind()).toEqual('scalene');
  });

  it('test triangles with no size are illegal', function() {
    var triangle = new Triangle(0,0,0);
    expect(triangle.kind.bind(triangle)).toThrow();
  });

  xit('triangles with negative sides are illegal', function() {
    var triangle = new Triangle(3,4,-5);
    expect(triangle.kind.bind(triangle)).toThrow();
  });

  xit('triangles violating triangle inequality are illegal', function() {
    var triangle = new Triangle(1,1,3);
    expect(triangle.kind.bind(triangle)).toThrow();
  });

  xit('edge cases of triangle inequality are in fact legal', function() {
    var triangle = new Triangle(2,4,2);
    expect(triangle.kind.bind(triangle)).not.toThrow();
  });

  xit('triangles violating triangle inequality are illegal 2', function() {
    var triangle = new Triangle(7,3,2);
    expect(triangle.kind.bind(triangle)).toThrow();
  });

  xit('triangles violating triangle inequality are illegal 3', function() {
    var triangle = new Triangle(10,1,3);
    expect(triangle.kind.bind(triangle)).toThrow();
  });

});

这是我的JavaScript...

function Triangle(sideA, sideB, sideC) {

    this.kind = function() {
        //
        // Your solution to the exercise goes here
        //
      var triangleType = "";  
      if (this.isValidTriangle()){
        if (sideA == sideB && sideB == sideC ) {
          triangleType="equilateral";
        }
        else if (sideA == sideB || sideB == sideC || sideA == sideC) {
          triangleType="isosceles";
        }
        else {
         triangleType="scalene";
        } 
      }
      else {
//          throw new Error('Invalid Triangle');
//          throw TypeError("Invalid Triangle");
//          throw "up";
          throw new RangeError("Test");
          } 
      return triangleType;    
    };
    this.isValidTriangle = function() {
        var sides = [sideA, sideB, sideC];
        for(var i = 0; i < sides.length; i++) {
            if(sides[i] = 0) {i = 3; return false;};
        };
        return true;
    };
};

module.exports = Triangle;

这是 Jasmine 输出...

c:\Users\EP\exercism\javascript>jasmine-node triangle --verbose

Triangle - 20 ms
    equilateral triangles have equal sides - 16 ms
    larger equilateral triangles also have equal sides - 1 ms
    isosceles triangles have last two sides equal - 0 ms
    isosceles trianges have first and last sides equal - 0 ms
    isosceles triangles have two first sides equal - 0 ms
    isosceles triangles have in fact exactly two sides equal - 0 ms
    scalene triangles have no equal sides - 0 ms
    scalene triangles have no equal sides at a larger scale too - 0 ms
    scalene triangles have no equal sides in descending order either - 0 ms
    very small triangles are legal - 0 ms
    test triangles with no size are illegal - 1 ms

Failures:

  1) Triangle test triangles with no size are illegal
   Message:
     Expected function to throw an exception.
   Stacktrace:
     Error: Expected function to throw an exception.
    at null.<anonymous> (C:\Users\EP\exercism\javascript\triangle\triangle.spec.js:57:42)

Finished in 0.053 seconds
11 tests, 11 assertions, 1 failure, 0 skipped

我知道我一定漏掉了什么。我已经阅读了 Jasmine 文档、JavaScript 文档、MDN，用谷歌搜索了它，但似乎无法确定我做错了什么。

更新：在 Whosebug 社区的帮助下，我解决了这个问题。下面是通过所有匹配器的最终代码（那些未决（退出）的都被激活（它）。

function Triangle(sideA, sideB, sideC) {

    this.kind = function() {
        //
        // Your solution to the exercise goes here
        //
      if (this.isValidTriangle() == false){ throw new TypeError("Invalid Triangle");}
      else if (sideA == sideB && sideB == sideC ) {
        triangleType="equilateral";
      }
      else if (sideA == sideB || sideB == sideC || sideA == sideC) {
        triangleType="isosceles";
      }
      else {
        triangleType="scalene";
      }
      return triangleType; 
    };

    this.isValidTriangle = function() {
        // no triangle inequality
        if(sideA + sideB < sideC) {return false;}
        if(sideB + sideC < sideA) {return false;}
        if(sideA + sideC < sideB) {return false;}       
        // no zero or negative sides
        var sides = [sideA, sideB, sideC];
        for(var i = 0; i < 3; i++) {
            if(sides[i] <= 0) {i = 3; return false;}; 
        };
        return true;
    };
}
module.exports = Triangle;

再次感谢所有帮助我回答问题的人！

Answer 1

原因在于您直接调用该方法，这会产生 javascript 错误，您需要传递一个将由 jasmine 调用的回调...这允许 jasmine 捕获您的错误：

describe("Something throws", () => {
  it("foo is not defined", () => {
    expect(() => { foo + 5 }).toThrow();

    // instead of:
    // expect(foo + 5).toThrow();
  });
});

Answer 2

绑定方法returns一个函数语句。您不能期望函数语句在您执行之前抛出异常。如果要同时更改上下文和执行函数，则需要使用 apply or call.

JavaScript 代码没有通过 Jasmine toThrow 测试

JavaScript code does not pass Jasmine toThrow test

javascript

jasmine-node