No test that you wouldn't have had done before

No test that you wouldn't have had done before

The above is a prediction, i.e. "From my experience as an eye specialist I can predict/surmise that you will have had this test before".

Strictly speaking the original isn't a complete sentence. We can make it so in various ways, e.g.

I shall administer no test that you wouldn't have had done before.

No test that you wouldn't have had done before will be given.

There will be no test that you wouldn't have had done before.

Those are perfectly correct, complete sentences.

Alternatives

No test that you won't have had done before. (prediction)

No test you haven't had done before. (certainty/knowledge)