字符串总和方法的 Junit 测试

Question

谁能给我两个java中这个函数的失败测试用例 有指定的输入和预期的结果？

public int sumOfString(String numbers){    
  if(numbers == null) throw new IllegalArgumentException(); 
  String[] parts = numbers.split(",");
  int sum = 0; 
  for (String string : parts)
  {
    sum += Integer.parseInt(string); 
  } 
  return sum; 
}

这是我尝试过的

public void testSumOfString() {
    String numbers = "13,4,,5";
    Engine instance = new Engine();
    int expResult = 22;
    int result = instance.sumOfString(numbers);
    assertEquals(expResult, result);
}
public void testSumOfString2() {
    String numbers = "13,A,5";
    Engine instance = new Engine();
    int expResult = 13 + 65 + 5;
    int result = instance.sumOfString(numbers);
    assertEquals(expResult, result);
}

Answer 1

您要么创建包含代码的对象，要么将类设为静态以用于测试目的。

//There are your two test cases
//One is when your code tries to accept an empty string
//One is when you're trying to sum alpha characters.
public void testSumOfString() {
       Assert.Equals(new IllegalArgumentException(),MyObject.sumOfString("")); // MyObject is your class
       // the string that I gave to the method can make the method work because it's empty
    Assert.Equals(new NumberFormatException(), MyObject.sumOfString("Assadsdfcdsvc"); 
    }

您应该更新代码以确保方法接收的字符串完全由整数值组成。一个好的开始是使用以下行更新您的代码

  //Update your code with the following 
if(str == null || str.isEmpty()) throw new IllegalArgumentException();