testing-example-apps

A testing workflow for py-shiny example applications using Playwright, a tool that drives web browsers for automated tests. It provides shared smoke tests to check that example apps load and interaction tests for key component examples.

In plain words
What is it for?
Use it when adding Playwright tests for Core and Express py-shiny component examples, using the repository’s shared fixtures and public testing API.
Why use it?
It avoids repeating basic test setup for every example and catches broken applications or user interactions before documentation is published.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/posit-dev/py-shiny-site/testing-example-apps
Any agent
npx skills add posit-dev/py-shiny-site --skill testing-example-apps
Clone the repo
git clone --depth 1 https://github.com/posit-dev/py-shiny-site

Made for: Claude Code, Codex.

Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,721 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00073 $0.01721
Opus 5 $0.00036 $0.00860
Sonnet 5 $0.00015 $0.00344
Haiku 4.5 $0.00007 $0.00172

Measured 2d ago against content hash 3382348638e1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

testing-example-apps scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/testing-example-apps/SKILL.md · 123 lines

How it starts

The opening of the file, as written. The whole thing — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Testing Example Apps

Overview

Component example apps (components/**/app.py, components/**/app-*.py) are the source of truth for each page — the shinylive links in index.qmd are generated from them. Smoke coverage (it loads with no server, JS, or output errors) is centralized: a single parametrized components/test_examples_smoke.py auto-discovers and smoke-tests every such app, one test_example_app_smoke[<relative path>] case per app. This skill covers adding py-shiny Playwright interaction tests for the primary Core + Express apps via py-shiny's controllers — you do not write per-component smoke tests.

Everything uses the public shiny package APIshiny.pytest.create_app_fixture, shiny.playwright.controller, shiny.run.ShinyAppProc. No custom test runner.

Reference implementation: components/layout/accordion/test_accordion.py.

Shared infrastructure (already in place — do not re-create)

  • pytest.ini (repo root): testpaths = components scopes pytest to the site's tests and away from the py-shiny/ submodule.
  • components/conftest.py provides:
    • create_example_fixture(HERE / "app-NAME.py") — returns a fixture yielding a running ShinyAppProc. Splits multi-file ## file: shinylive apps into a temp dir; launches single-file apps directly.
    • smoke_test fixture — a callable smoke_test(page, app, *, allow_stderr=(), allow_js=()) that navigates, waits for Shiny idle, and asserts no un-allow-listed server stderr, no JS console errors, and zero .shiny-output-error.
    • example_app_paths() / launch_example_app() — power the centralized smoke sweep below; you generally don't call these directly from a component's test_<name>.py.
  • components/test_examples_smoke.py — smoke-tests EVERY discovered example app (app.py / app-*.py) as its own parametrized case; you do NOT write per-component smoke tests.
  • components/test_component_pages.py — a static (non-browser) check that every component page (components/<section>/<name>/index.qmd) ships at least one example app (app.py / app-*.py). All discovered pages are enforced; a page may only opt out via EXEMPT_PAGES (normally empty) with a documented reason. Runs under make test-components-examples.

Read the full file on GitHub · 123 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 123 lines · 73 tokens per session scan A 3382348638e1

Subscribe to this mod's changes

testing-example-apps is a skill published in the GitHub repository posit-dev/py-shiny-site (22 stars, last pushed 19d ago), licensed MIT. It adds 73 tokens to every session and 1,721 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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