loadout playwright-python.instructions.md

Instructions for writing end-to-end browser tests in Python with Playwright. These tests operate a real browser to check web pages and user flows.

In plain words
What is it for?
Use it to create or maintain Python tests that automate web applications in Chromium, Firefox, or WebKit.
Why use it?
It helps avoid fragile tests and provides consistent approaches for accessibility, regression, and browser coverage.

Instructions file for GitHub Copilot

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 instructions/stefaniuk/loadout/playwright-python
Clone the repo
git clone --depth 1 https://github.com/stefaniuk/loadout

Made for: GitHub Copilot.

Per session 2,443 This file is loaded in full into every session.
When invoked 2,443 The same file — it is already loaded in full.
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 $0.02443 $0.02443
Opus 5 $0.01222 $0.01222
Sonnet 5 $0.00489 $0.00489
Haiku 4.5 $0.00244 $0.00244

Measured yesterday against content hash d0cffb29a264, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

loadout playwright-python.instructions.md 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 yesterday.

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.

.github/instructions/playwright-python.instructions.md · 172 lines

How it starts

The opening of the file, as written. The whole thing — 172 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Playwright Python Test Generation Instructions 🎭

These instructions define the default engineering approach for writing production-grade end-to-end tests using Playwright with Python.

They must remain applicable to:

  • Web application testing with Playwright sync API
  • Browser automation and UI testing
  • Accessibility and regression testing
  • Cross-browser testing (Chromium, Firefox, WebKit)

They are non-negotiable unless an exception is explicitly documented (with rationale and expiry) in an ADR/decision record.

Cross-references. For general Python engineering standards (typing, error handling, code organisation), see python.instructions.md. This file focuses exclusively on Playwright-specific testing patterns.

Shared baseline. For language-agnostic Playwright guidance, see playwright-baseline.include.md.

Identifier scheme. Every normative rule carries a unique tag in the form [PW-PY-<prefix>-NNN], where the prefix maps to the containing section (for example QR for Quick Reference, LOC for Locators, AST for Assertions, STR for Structure). Use these identifiers when referencing, planning, or validating requirements.


0. Quick reference (apply first) 🧠

This section exists so humans and AI assistants can reliably apply the most important rules even when context is tight.

  • [PW-PY-QR-001] Role-based locators: prioritise get_by_role, get_by_label, get_by_text for resilience and accessibility ([PW-PY-LOC-001]).
  • [PW-PY-QR-002] Web-first assertions: use auto-retrying expect API; avoid .to_be_visible() unless testing visibility changes ([PW-PY-AST-001]).
  • [PW-PY-QR-003] No hard-coded waits: rely on Playwright's built-in auto-waiting mechanisms ([PW-PY-LOC-004]).
  • [PW-PY-QR-004] Descriptive test titles: use clear, intent-revealing function names ([PW-PY-STR-004]).
  • [PW-PY-QR-005] Standard imports: begin files with from playwright.sync_api import Page, expect ([PW-PY-STR-001]).
  • [PW-PY-QR-006] Consistent file naming: follow test_<feature>.py convention ([PW-PY-ORG-002]).
  • [PW-PY-QR-007] Prefer expect over assert: use Playwright's expect for more reliable UI tests ([PW-PY-AST-004]).
  • [PW-PY-QR-008] Avoid common anti-patterns: time.sleep(), force=True clicks, shared mutable state, tests without assertions (§9).

Read the full file on GitHub · 172 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. yesterday First seen · 172 lines · 2,443 tokens per session scan A d0cffb29a264

Subscribe to this mod's changes

loadout playwright-python.instructions.md is an instructions file published in the GitHub repository stefaniuk/loadout (1 stars, last pushed 3d ago), licensed MIT. It adds 2,443 tokens to every session, about $0.0122 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 2026-08-31.