Did you have a situation where you did not have any documents (no requirement document, no Use Cases, or no Design Document) and you had to write the Test Cases? How did you write the Test Cases in this situation?

Yes. I have been to that kind of scenarios several times. There were companies where they had no documents at all. In that case, I had to discuss the application scenario and functionalities with the Business Analysts or developer. On the basis of that discussion, I prepared a document in consultation with Business Analysts and Developers and then started writing Plans and Test Cases.