File uploading in headless app testing?

I am really excited to learn about AppTest in the 1.28.0 release of Streamlit (docs and blog), so that we can finally write tests easily for our Streamlit UI, in addition to the background processes being activated through the UI.

Our Streamlit app operates on user-uploaded CSVs. However, in the AppTest documentation, Iā€™m not seeing any methods for testing st.file_uploader. Is there any approach for testing file uploads or any workaround for sending data to pages/functions that involve a file upload at the moment?