Testing of parameterized function in streamlit

[ss_mohanty]

In a streamlit project, i have two pages and these two pages depends upon other moudules and these module contains several functions. one of the function i have mentioned below i.e

def delete_items(connection,id,db,schema, table):
    col1, col2 = st.columns([0.1,1])  # Adjust the column widths as needed
    with col1:
        st.button("Yes",on_click=confirm_delete, args=[connection,id,db,schema, table])
        
    with col2:
        st.button("No",on_click=set_state, args=[0])
    

i am little confused that do i really need to test each and every function. if yes, how we can achieve it ?

for testing i tried

def test_delete_items():
    ' ' ' test wheather item is deleted ' ' ' 
    app = AppTest.from_function(delete_items).run(timeout=5)
    assert app.columns
    # assert app.columns[0
    assert 'Yes' in app.button[0].label
    assert 'No' in app.button[1].label

however it failed. because the actual function takes some arguments and i am confusing how to ingest those arguments from the test file itself. i tried with *args to ingest arguments but also failed.
any kind of support would be highly appreciated.
cheers,
Swetansu

[sahirmaharaj]

Hello @ss_mohanty ,

Here’s how you might approach it using pytest and unittest.mock:

from unittest.mock import patch, MagicMock
import pytest

# Your function (simplified for demonstration)
def delete_items(connection, id, db, schema, table):
    col1, col2 = st.columns([0.1, 1])
    with col1:
        st.button("Yes", on_click=confirm_delete, args=[connection, id, db, schema, table])
    with col2:
        st.button("No", on_click=set_state, args=[0])

# Test function
def test_delete_items():
    with patch('streamlit.columns') as mock_columns, \
         patch('streamlit.button') as mock_button:
        # Mock the columns and button
        mock_col1 = MagicMock()
        mock_col2 = MagicMock()
        mock_columns.return_value = [mock_col1, mock_col2]
        mock_button.side_effect = [None, None]  # Assuming no return value from button

        # Call the function with mock arguments
        delete_items('connection', 'id', 'db', 'schema', 'table')

        # Assertions
        mock_columns.assert_called_once_with([0.1, 1])
        assert mock_button.call_count == 2
        mock_button.assert_any_call("Yes", on_click=confirm_delete, args=['connection', 'id', 'db', 'schema', 'table'])
        mock_button.assert_any_call("No", on_click=set_state, args=[0])

Kind Regards,
Sahir

P.S. Lets connect on LinkedIn!

[ss_mohanty]

Thank you Sahir for your valuable feedback