CODEWITHSUNDEEP
javaunit-testingjunitnullpointerexceptionjunit5
andrew_savich
andrew_savich

Reputation: 43

How can I test method which throws NullPointerException using JUnit 5

How can I test method which throws NullPointerException using JUnit 5. But I catch this exception in the method, so test is ending with error: "Expected java.lang.NullPointerException to be thrown, but nothing was thrown."

class MyClass {
   void myMethod() {
        try {
            //do somthing
            throw new NullPointerException();
        } catch(NullPointerException e) {
            //tell about exception
        }
   }
}

class MyClassTest {  
  @Test 
  void shouldThrowNullPointerException() {
       MyClass odj = new MyClass();
       
       Assertions.assertThrows(NullPointerException.class, () -> obj.myMethod());      
   }
}

Thank you

Upvotes: 0

Views: 3545

Answers (1)

EricSchaefer
EricSchaefer

Reputation: 26340

assertThrows is meant for uncaught exception. It makes no sense for cases where the method catches the exception. You can not test for that directly. If //do somthing is doing something that you can observe from outside your method, then you can assert on that (i.e. if your catch block would return nullor some other value to signify that an error occured.

Upvotes: 3

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