J- Unit Test: Make static method void on class exception
I am writing J-Unit Tests for my project and now this problem came up:
I am testing a servlet that uses the Utility class (the class is final, all methods are static). The method used returns void and can call
IOException (httpResponse.getWriter).
Now I need to force this exception ...
I tried a lot and searched a lot, but all the solutions I found didn't work because I was no combination of final, static, void, throw
.
Has anyone done this before?
EDIT: Here is a piece of code
Servlet:
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
try {
String action = request.getParameter("action");
if (action.equals("saveRule")) {
// Some code
String resp = "blablabla";
TOMAMappingUtils.evaluateTextToRespond(response, resp);
}
} catch (IOException e) {
TOMAMappingUtils.requestErrorHandling(response, "IOException", e);
}
}
Utils class:
public final class TOMAMappingUtils {
private static final Logger LOGGER = Logger.getLogger(TOMAMappingUtils.class.getName());
private static final Gson GSON = new Gson();
public static void evaluateTextToRespond(HttpServletResponse response, String message) throws IOException {
// Some Code
response.getWriter().write(new Gson().toJson(message));
}
}
Test Method:
@Test
public void doPostIOException () {
// Set request Parameters
when(getMockHttpServletRequest().getParameter("action")).thenReturn("saveRule");
// Some more code
// Make TOMAMappingUtils.evaluateTextToRespond throw IOExpection to jump in Catch Block for line coverage
when(TOMAMappingUtils.evaluateTextToRespond(getMockHttpServletResponse(), anyString())).thenThrow(new IOException()); // This behaviour is what i want
}
So, as you can see, I want to force the Utils method to throw an IOException, so I ended up in a catch block for better line coverage.
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To make fun of the final class, first add it to prepareForTest
.
@PrepareForTest({ TOMAMappingUtils.class })
Then layout as static class
PowerMockito.mockStatic(TOMAMappingUtils.class);
Then set your expected value below.
PowerMockito.doThrow(new IOException())
.when(TOMAMappingUtils.class,
MemberMatcher.method(TOMAMappingUtils.class,
"evaluateTextToRespond",HttpServletResponse.class, String.class ))
.withArguments(Matchers.anyObject(), Matchers.anyString());
Another way:
PowerMockito
.doThrow(new IOException())
.when(MyHelper.class, "evaluateTextToRespond",
Matchers.any(HttpServletResponse.class), Matchers.anyString());
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