download_button with data=callable runs without ScriptRunContext

[DavidWalz]

Checklist

• I have searched the existing issues for similar issues.
• I added a very descriptive title to this issue.
• I have provided sufficient information below to help reproduce this issue.

Summary

When using the newly introduced option to provide a callable as data argument, the callable runs without ScriptRunContext.

Reproducible Code Example

# app.py
import csv
import io

import streamlit as st


def to_csv() -> str:
    foo = st.session_state.get("foo", "nope")
    print(foo)
    buffer = io.StringIO()
    writer = csv.writer(buffer)
    writer.writerow([foo])
    buffer.seek(0)
    return buffer.getvalue()


st.download_button(
    label="Download",
    data=to_csv,
    file_name="foo.csv",
    mime="text/csv",
)

st.session_state["foo"] = "bar"

Steps To Reproduce

1. streamlit run app.py
2. Click the button

Raises Thread 'asyncio_0': missing ScriptRunContext! This warning can be ignored when running in bare mode.

Expected Behavior

When called from the download_button, the function to_csv should have context, and see the currenct session_state.

Current Behavior

Warning

Thread 'asyncio_0': missing ScriptRunContext! This warning can be ignored when running in bare mode.

Is this a regression?

• Yes, this used to work in a previous version.

Debug info

• Streamlit version: 1.52.2
• Python version: 3.13
• Operating System: Win
• Browser: Chrome

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[DavidWalz]

Somehow I missed this issue #13337
Closing as duplicate