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.
git clone --depth 1 https://github.com/thematters/matters-webWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/rules/thematters/matters-web/testing-approach)<a href="https://agentmods.dev/rules/thematters/matters-web/testing-approach"><img src="https://agentmods.dev/badge/rules/thematters/matters-web/testing-approach/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/rules/thematters/matters-web/testing-approach"><img src="https://agentmods.dev/badge/rules/thematters/matters-web/testing-approach.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00007 | $0.00463 |
| Opus 5.5 | $0.00003 | $0.00185 |
| Sonnet 5.5 | $0.00001 | $0.00093 |
| Haiku 4.5 | $0.00001 | $0.00046 |
Grade A, and why
testing-approach 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 1mo 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.
What it actually says
Testing Approach
Matters Web uses a combination of unit, component, and end-to-end (E2E) tests.
Testing Framework
- Vitest and Testing Library for unit and component tests
- Playwright for end-to-end (E2E) tests
Test Structure
- Unit and component tests are typically located in a
ComponentName.test.tsxfile within each component - End-to-end tests are in the
tests/directory
Running Tests
npm run test: Run all testsnpm run test:unit: Run unit and component testsnpm run test:e2e: Run end-to-end testsnpm run test:unit:coverage: Generate coverage report
Release Evaluation Boundary
Use the shared release evaluation standard when testing feature launches:
- Preview and PR checks should use the Vercel preview URL through
PLAYWRIGHT_TEST_BASE_URL. matters.icuis the staging acceptance target and may use disposable test data.matters.townproduction checks are read-only by default; production mutations, admin actions, payment actions, moderation changes, or outbound delivery require explicit human approval.- Keep CI status, staging acceptance, production deployment, and production smoke-test results separate.
See docs/e2e-release-evaluation.md for the repo-local guide.
Testing Utilities
- Mock data and fixtures for testing
- Utility functions for common test operations
- Custom test renderers for components with specific requirements
Key Test Files
- vitest.config.ts: Vitest configuration
- vitest.setup.ts: Vitest setup file
- playwright.config.ts: Playwright configuration
Testing Best Practices
- Make sure to create corresponding unit tests when adding a new component.
- Tests should be independent and not rely on the state of other tests
- Use testing-library queries that align with how users interact with the application
- Mock API responses for component tests
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.
- 1mo ago First seen · 56 lines · 7 tokens per session scan A a37a4c24d9fe
testing-approach is a cursor rule published in the GitHub repository thematters/matters-web (86 stars, last pushed 5d ago), licensed Apache-2.0. It adds 7 tokens to every session and 463 once invoked, about $0.0000 per session on Opus 5.5. 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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