基本的jUnit问题(Basic jUnit Questions)

 我正在用一个multiply()方法测试一个String乘数类，该方法以2个数字作为输入（如String ）并返回结果数字（如String ） 
 
public String multiply(String num1, String num2);      
 
 我已经完成了实现并创建了一个测试类，其中包含以下与输入String参数as相关的测试用例 
 
 
 
 有效的数字 
 
 
 人物 
 
 
 特殊符号 
 
 
 空字符串 
 
 
 空值 
 
 
 0 
 
 
 负数 
 
 
 浮动 
 
 
 边界值 
 
 
 有效但其产品超出范围的数字 
 
 
 数字会加号（+23） 
 
 
 现在我的问题是这些： 
 
 
 
 我想知道“每一个”assertEquals（）是否应该在它自己的测试方法中？ 或者，我可以将类似的测试用例（如testInvalidArguments（））分组以包含涉及无效字符的所有断言，因为它们都引发相同的NumberFormatException？ 
 
 
 如果测试像字符（“a”）这样的输入值，是否需要为所有场景包含测试用例？ “a”作为第一个参数“a”作为第二个参数“a”和“b”作为2个参数 
 
 
 根据我的理解，这些单元测试的好处是要找出用户输入可能失败并导致异常的情况。 然后，我们可以给用户一个有意义的消息（要求他们提供有效的输入）而不是例外。 这是正确的吗？ 而且，这是唯一的好处吗？ 
 
 
 上面提到的11个测试用例是否足够？ 我错过了什么？ 我过度了吗？ 什么时候够了？ 
 
 
 从上述观点来看，我是否成功地测试了multiply（）方法？ 
 

I was testing a String multiplier class with a multiply() method that takes 2 numbers as inputs (as String) and returns the result number (as String) 
 
public String multiply(String num1, String num2);      
 
I have done the implementation and created a test class with the following test cases involving the input String parameter as 
 
 
 
valid numbers 
 
 
characters 
 
 
special symbol 
 
 
empty string 
 
 
Null value 
 
 
0 
 
 
Negative number 
 
 
float 
 
 
Boundary values 
 
 
Numbers that are valid but their product is out of range 
 
 
numbers will + sign (+23) 
 
 
Now my questions are these:
 
 
 
I'd like to know if "each and every" assertEquals() should be in it's own test method? Or, can I group similar test cases like testInvalidArguments() to contains all asserts involving invalid characters since ALL of them throw the same NumberFormatException ? 
 
 
If testing an input value like character ("a"), do I need to include test cases for ALL scenarios? "a" as the first argument "a" as the second argument "a" and "b" as the 2 arguments 
 
 
As per my understanding, the benefit of these unit tests is to find out the cases where the input from a user might fail and result in an exception. And, then we can give the user with a meaningful message (asking them to provide valid input) instead of an exception. Is that the correct? And, is it the only benefit? 
 
 
Are the 11 test cases mentioned above sufficient? Did I miss something? Did I overdo? When is enough? 
 
 
Following from the above point, have I successfully tested the multiply() method? 
 

原文：https://stackoverflow.com/questions/2710545