JMockit / Netbeans - verify AccessController.doPrivileged() was called

Question

I am using JMockit 1.12 and want to verify that AccessController.doPrivileged() was called. This seems rather straightforward:

@Test(expected = MissingInvocation.class)
public void testFoo1() {
    foo(false, true);
}

@Test
public void testFoo2() {
    foo(false, false);
}

@Test
public void testFoo3() {
    foo(true, true);
}

private void foo(boolean usePrivilegedAccess, boolean expectAccessControllerCall) {
    new NonStrictExpectations(AccessController.class) {{
    }};

    if (usePrivilegedAccess) {
        AccessController.doPrivileged((PrivilegedAction<String>) () -> "");
    }

    // verify AccessController.doPrivileged was called
    if (expectAccessControllerCall) {
        new Verifications() {{ AccessController.doPrivileged(withAny((PrivilegedAction<Object>) () -> null )); }};
    }
}

Note that testFoo1() does not call AccessController.doPrivileged() yet performs the check anyway.

I added this method because I found that sometimes the Verifications block would pass even if AccessController.doPrivileged(). I am using Netbeans 8.0.1 and after a lot of testing, I found that if I run the test using "Run Focused Test Method" or "Debug Focused Test Method" (runs only 1 test) then it passes. If I use "Test File" (runs all tests) then testFoo1() fails because it does not throw MissingInvocation. If I use "Debug Test File" (runs all tests) then it always fails if I put in a breakpoint; it intermittently fails if I do not put in a breakpoint. Very strange.

Is my JMockit usage correct? I am new, so any pointers appreciated but please note that I want to run the exact same test code from 2 tests which only differ by a boolean flag. I do not want to copy/paste the test twice.

Is there something up with Netbeans?

Is it something to do with the CGLib injection somewhere in the pipeline?

Answer 1

What probably happens is that, during the test, AccessController.doPrivileged(...) gets called from somewhere else, perhaps from NetBeans or more likely from the JRE itself.

JMockit 1.x does not restrict the mocking of the AccessController class to just the foo(boolean,boolean) method; instead, it registers all invocations to its methods, regardless of where they come from. The test would have to implement a more restrictive verification, perhaps checking the exact PrivilegedAction instance passed to the mocked method, or even by checking the call stack to see where it comes from.

For JMockit 2, an API change is planned so that mocking gets scoped to @Tested classes only, avoiding situations like this.