Testing

Have the computer make the checks you may be doing visually
Have the checks done in code

Setup

requirements.txt

pytest
pytest-playwright

Install browers

playwright install

Run tests

Call pytest!

pytest

See the test in the browser

pytest --headed

or specify a specific brower

pytest --brower firefox

Testing Shiny

Testing is always great (nothing new here)
Playwright is the more modern way to test web apps
- Compared to Selenium…
Shiny makes playwright easier to code against

Pytest Example

import pandas as pd

idx1 = pd.Index([1, 2, 3, 4, 5])
idx2 = pd.Index([2, 3, 4, 5, 6])
idx3 = pd.Index([3, 4, 5, 6, 7])
default = pd.Index([1, 2, 3, 4, 5, 6, 7])

def test_index_intersection_all():
    to_intersect = [idx1, idx2, idx3]
    expected = pd.Index([3, 4, 5])
    calculated = index_intersection_all(
        to_intersect,
        default=default,
    )
    assert (calculated == expected).all()
    assert calculated.equals(expected)

Playwright Example

https://shiny.posit.co/py/api/testing/

from shiny.playwright import controller
from shiny.run import ShinyAppProc
from playwright.sync_api import Page
from shiny.pytest import create_app_fixture

app = create_app_fixture("app.py")

def test_basic_app(page: Page, app: ShinyAppProc):
    page.goto(app.url)

    selectize_day = controller.InputSelectize(page, "adaptive-filter_day")
    selectize_day.set("Fri")
    selectize_day.expect_selected(["Fri"])

    selectize_time = controller.InputSelectize(page, "adaptive-filter_time")
    selectize_time.expect_choices(["Dinner"])