Jasmine 无法读取未定义的属性“长度”

Question

嗨，我是单元测试的新手，我编写了一个程序，它接受 3 个参数，两个罗马字母和一个运算符（+，-，/，*）它应该执行操作，它应该返回 romanLetters 中的值我正在尝试编写一个对该问题的单元测试它说无法读取未定义的属性长度我不知道为什么会发生我的代码运行良好。我在这里附上我的代码

Mainjs 文件

var main=function(operand1,operand2,operator) {
    var concat,number;
    var operand1=romantonumerals(operand1);
    var operand2=romantonumerals(operand2);
    //var operator=operatorconversion(operator);
    console.log("operand1 "+operand1);
    console.log("operand2 "+operand2);
    if(operand1>operand2) {
      concat=operand1+operator+operand2;
    }
    else {
      concat=operand2+operator+operand1;
    }
    number=Math.round(eval(concat));
    console.log(number);
    if(number<500) {
      result=numeralstoroman(number)
    }
    else if(number===0) {
      result="Make sure its greater than 0";
    }
    else {
      result="Make sure your number gets less than 500 try with some other romans";
    }
    console.log(result);
    return result;
  };
  var numeralstoroman=function(number) {
    var roman="",temp;
    var ones=function(number) {
      switch (number) {
        case 1:
          roman+="I";
          break;
        case 2:
          roman+="II";
          break;
        case 3:
          roman+="III";
          break;
        case 4:
          roman+="IV";
          break;
        case 5:
          roman+="V";
          break;
        case 6:
          roman+="VI";
          break;
        case 7:
          roman+="VII";
          break;
        case 8:
          roman+="VIII";
          break;
        case 9:
          roman+="IX";
          break;
      }
    };
    var twos=function(number) {
      if(number>=10 && number<20) {
        roman+="X";
        ones(number%10);
      }
      else if(number>=20 && number30) {
        roman+="XX";
        ones(number%10);
      }
      else if(number>=30 && number<40) {
        roman+="XXX";
        ones(number%10);
      }
      else if(number>=40 && number<50) {
        roman+="XL";
        ones(number%10);
      }
      else if(number>=50 && number<60) {
        roman+="L";
        ones(number%10);
      }
      else if(number>=60 && number<70) {
        roman+="LX";
        ones(number%10);
      }
      else if(number>=70 && number<80) {
        roman+="LXX";
        ones(number%10);
      }
      else if(number>=80 && number<90) {
        roman+="LXXX";
        ones(number%10);
      }
      else if(number>=90 && number<100) {
        roman+="XC";
        ones(number%10);
      }
    };
    var threes=function(number) {
      if(number>=100 && number<200) {
          roman+="C";
          if(number%100<10) {
            ones(number%10);
          }
          else {
            twos(number%100);
          }
      }
      else if(number>=200 && number<300) {
          roman+="CC";
          if(number%100<10) {
            ones(number%10);
          }
          else {
            twos(number%100);
          }
      }
      else if(number>=300 && number<400) {
          roman+="CCC";
          if(number%100<10) {
            ones(number%10);
          }
          else {
            twos(number%100);
          }
      }
      else if(number>=400 && number<500) {
          roman+="CD";
          if(number%100<10) {
            ones(number%10);
          }
          else {
            twos(number%100);
          }
      }
    }
    if(number<10) {
      ones(number);
    }
    else if(number>=10 && number<100) {
      twos(number);
    }
    else if(number>=100 && number<500) {
      threes(number);
    }
    console.log(roman);
    return roman;
  };
  var character=function(str) {
    switch(str) {
      case "I":
        return 1
      case "V":
        return 5
      case "X":
        return 10
      case "L":
        return 50
      case "C":
        return 100
      case "D":
        return 500
      default:
        return -1;
    }
  }
  var romantonumerals=function(operand) {
    var no=0,i=0,char1="",char2="";
    while(i<operand.length) {
      char1=character(operand[i]);
      if(i+1<operand.length) {
        char2=character(operand[i+1]);
        if(char1>=char2) {
          no+=char1;
          i++;
        }
        else {
          no=no+(char2-char1);
          i+=2;
        }
      }
      else {
        no+=char1;
        i++;
      }
    }
    return no;
  };
  var ans=main("V","I","+");
  console.log(ans);

JasmineHTML 文件

<!DOCTYPE html>
  <html>
  <head>
    <meta charset="utf-8">
    <title>Jasmine Spec Runner v2.2.0</title>

    <link rel="shortcut icon" type="image/png" href="lib/jasmine-2.2.0/jasmine_favicon.png">
    <link rel="stylesheet" href="lib/jasmine-2.2.0/jasmine.css">

    <script src="lib/jasmine-2.2.0/jasmine.js"></script>
    <script src="lib/jasmine-2.2.0/jasmine-html.js"></script>
    <script src="lib/jasmine-2.2.0/boot.js"></script>

    <!-- include source files here... -->
    <script src="romtantonumeralstoroman.js"></script>
    <!-- include spec files here... -->
    <script src="spec.js"></script>


  </head>

  <body>
  </body>
  </html>

茉莉花测试文件

describe("A suite", function() {
it("contains spec with an expectation", function() {
    main();
    expect(main("V","I","+").toBe("VI"));
});
});

JSFIDDLE 链接

https://jsfiddle.net/pLecneto/

Answer 1

问题是您调用 main(); 时在您的规范中没有任何参数。删除它，因为当操作数为 undefined 时，它会在 while(i<operand.length) 处引发异常。

并更改您的 expect 声明，例如：

expect(main("V","I","+")).toBe("VI");