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.
npx agentmods add rules/arjshiv/localutils-mcp-server/testinggit clone --depth 1 https://github.com/arjshiv/localutils-mcp-serverWhat 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 | $0.00000 | $0.00310 |
| Opus 5 | $0.00000 | $0.00155 |
| Sonnet 5 | $0.00000 | $0.00062 |
| Haiku 4.5 | $0.00000 | $0.00031 |
Grade A, and why
testing 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.
What it actually says
Testing Standards
Test Organization
- Place tests in
__tests__directory - Name test files with
.test.tsor.spec.tssuffix - Group related tests in describe blocks
- Use clear, descriptive test names
Test Structure
- Follow AAA pattern:
- Arrange - Set up test data
- Act - Execute the code being tested
- Assert - Verify the results
Test Coverage
- Aim for 80%+ code coverage
- Test both success and error cases
- Test edge cases and boundary conditions
- Include integration tests for critical paths
Best Practices
- Keep tests independent
- Avoid test interdependence
- Clean up after each test
- Use beforeEach/afterEach for setup/teardown
- Mock external dependencies
Assertions
- Use explicit assertions
- One assertion per test when possible
- Use appropriate matchers
- Include meaningful error messages
Mocking
- Mock external dependencies
- Use jest.mock() for module mocking
- Reset mocks between tests
- Verify mock calls when relevant
Test Data
- Use factories for test data
- Keep test data minimal
- Use meaningful test data names
- Avoid sharing mutable test data
Performance
- Keep tests fast
- Avoid unnecessary async operations
- Use setup/teardown hooks efficiently
- Group similar tests together
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.
- yesterday First seen · 55 lines · 0 tokens per session scan A 8387da8128f0
testing is a cursor rule published in the GitHub repository arjshiv/localutils-mcp-server (2 stars, last pushed 8mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 310 tokens. 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.
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