How to mock a String using mockito?
- by Alceu Costa
I need to simulate a test scenario in which I call the getBytes() method of a String object and I get an UnsupportedEncodingException.
I have tried to achieve that using the following code:
String nonEncodedString = mock(String.class);
when(nonEncodedString.getBytes(anyString())).thenThrow(new UnsupportedEncodingException("Parsing error."));
The problem is that when I run my test case I get a MockitoException that says that I can't mock a java.lang.String class.
Is there a way to mock a String object using mockito or, alternatively, a way to make my String object throw an UnsupportedEncodingException when I call the getBytes method?
Here are more details to illustrate the problem:
This is the class that I want to test:
public final class A{
public static String f(String str){
try{
return new String(str.getBytes("UTF-8"));
} catch (UnsupportedEncodingException e) {
// This is the catch block that I want to exercise.
...
}
}
}
This is my testing class (I'm using JUnit 4 and mockito):
public class TestA {
@Test(expected=UnsupportedEncodingException.class)
public void test(){
String aString = mock(String.class);
when(nonEncodedString.getBytes(anyString())).thenThrow(new UnsupportedEncodingException("Parsing error."));
A.f(aString);
}
}
