I definitely know cases of businesses and start ups - either offering to buy out or employ another party, asking for access to code and other secret information

I definitely know cases of businesses and start ups - either offering to buy out or employ another party, asking for access to code and other secret information, requiring NDAs, and then making off. I would personally never share more than some small snippets of code. Throw those snippets on a different repo and that’s it. If they demand to see more of the code base, ask them specifically what they’d like. If they want the entire project, I wouldn’t proceed any further.