Transactionality in storage

What is the transactional reliability of storage in extensions? Say I have a JSON graph with 10k nodes. I want to write into storage using the background. If a user closes the browser, will that write transactionally work. By transactionally work, I mean will that write either completely succeed or completely fail? I can live with a complete failure. I don’t want a partial graph.

Thank you.

I assume you mean browser.storage.local? I’d recommend indexedDB for large datasets in general, not that it changes the fact that I can’t answer the question in general.