Is there a way for me to wildcard a friend class in C++?

I'm using gtest to unit test a cpp class. Consider a situation in which I'd like to make the test class a friend of the actual class, so it can unit test its private state. This works fine for me. The problem is that while using the very helpful TEST_P macro which allows you to parameterize test instantiation, the framework mangles the test name a bit.

So I have something like

class FooTester {
    FooTester() {}
}

TEST_P(FooTester, TestCoolFeature) {
// test my cool feature that needs access to Foo's internal state
}

which is great but to allow this I must provide

class Foo {
    friend class FooTester_TestCoolFeature;
}

we can see through macro magic gtest creates a new class I haven't explicitly declared which is a combination of the test class and the test method name.

This is ostensibly fine but a bit ugly. It would require me to add a new friend class for each new test method which requires this access. The only real, if unlikely, problem is that if gtest were to change its implementation and mangle the class names differently, it could break my tests.

Is there a way to use some #define magic or similar to declare all FooTester* classes as friends?