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/prest/prest/unit-tests-tddgit clone --depth 1 https://github.com/prest/prestWhat 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 | $0.00375 | $0.00375 |
| Opus 5 | $0.00187 | $0.00187 |
| Sonnet 5 | $0.00075 | $0.00075 |
| Haiku 4.5 | $0.00038 | $0.00038 |
Grade A, and why
unit-tests-tdd 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.
What it actually says
Unit Tests & TDD
TDD (behavior changes)
For adding or changing behavior: failing unit test first → implement → refactor. Do not land production code without a red→green cycle.
Coverage bar
Unit tests for packages under change must cover ≥80% of that package’s existing code (not only new lines). Verify before done:
go test -timeout 30s -race -cover ./path/to/package/...
# or full unit suite (writes coverage.out):
make test-unit
Fail the task if package coverage is under 80%.
Placement & isolation
- Co-located
<source>_test.go(e.g.config.go→config_test.go) - Mock ports via
adapters/mockgen/; never live DB orpostgres.Load()in unit tests - Outside
adapters/postgres/, mock ports — not concrete postgres types
Parallelism
- Prefer
t.Parallel()when safe (no shared mutable state / ordering) - Never with
t.Setenv, mutatedconfig.Load(),SetDBConnectForTest, or shared globals
Controllers / HTTP
TDD unit tests do not replace E2E. Every behavior change MUST also ship an
integration test — this is not optional for controller/HTTP-adjacent code, it
is the gate that catches a sibling code path a mocked unit test structurally
cannot see (e.g. a second query-param builder reusing weaker validation than
the one under test). See integration-tests.mdc (MUST section) and skill
prest-integration-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.
- 2d ago First seen · 45 lines · 375 tokens per session scan A adccb40c4efb
unit-tests-tdd is a cursor rule published in the GitHub repository prest/prest (4,614 stars, last pushed 5d ago), licensed MIT. It adds 375 tokens to every session, about $0.0019 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.
Other cursor rules, from other repositories
tutorial-system-guide
This guide documents the complete tutorial infrastructure in Windmill's frontend, enabling developers to create new interactive tutorials without re-exploring the codebase.
windmill-overview
Windmill is an open-source developer platform for building internal tools, API integrations, background jobs, workflows, and user interfaces. It offers a unified system where scripts are automatically turned into sharable UIs and can be composed into flows or embedded in custom applications.
testing
Cursor rule "testing" from kanyun-inc/reskill, covering testing rules, testing philosophy, spec-driven tdd workflow, benefits of test-first approach and example: adding --dry-run option.
python_tests
We use the unit tests to cover internal behavior that can work without the web / backend counterpart. We aim for 95%+ unit test coverage of our Python code in lib/streamlit.
upgrade-tests
// ✅ CORRECT: Upgrade package pattern await using ctx = testReactResource(appRouter, { server: { // server configuration }, client(opts) { return { links: [ httpLink({ url: opts.httpUrl, // client configuration }), ], }; }, }).
spec
Shared RSpec conventions for the gem suite.