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/nedcodes-ok/cursor-doctor/testinggit clone --depth 1 https://github.com/nedcodes-ok/cursor-doctorWhat 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 | $0.00797 | $0.00797 |
| Opus 5 | $0.00398 | $0.00398 |
| Sonnet 5 | $0.00159 | $0.00159 |
| Haiku 4.5 | $0.00080 | $0.00080 |
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.
How it starts
The opening of the file, as written. The whole thing — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Testing Rules
Test Structure
- Arrange-Act-Assert: set up data → call the thing → check the result. Consistent structure makes every test scannable
- One behavior per test — multiple
assertcalls checking the same behavior is fine (assertThat(user).hasName("Alice"); assertThat(user).isActive()). Multiple unrelated assertions is not - Test names describe the scenario and expectation:
returnsNullWhenUserNotFound,throwsWhenEmailIsDuplicate— nottest1,testUser, orshouldWork - Tests must be independent. If reordering tests breaks them, you have shared mutable state — a test that only passes after another test runs is two bugs
What to Test
- Test behavior from the caller's perspective, not implementation details. "When I call createOrder with valid items, I get an order with the correct total" — not "createOrder calls calculateSubtotal then calls applyTax then calls saveToDb"
- Edge cases are where bugs live: empty collections, zero/negative values, null/undefined, boundary values (off-by-one), Unicode, very long strings, concurrent access
- Error paths are as important as happy paths — test that invalid input returns the right error, not just that valid input works
- Don't test framework/library code. If you're testing that
Array.sort()sorts, you're wasting time. Test YOUR code's behavior when it uses the sort result
Mocking Strategy
- Mock at boundaries: HTTP clients, databases, file system, clocks, randomness — things that are slow, non-deterministic, or have side effects
- Never mock the system under test. If you're mocking half the class to test the other half, the class is doing too much — split it
- Prefer fakes over mocks when the boundary is complex: an in-memory repository that implements the same interface is more realistic than 20 mock configurations
- Verify interactions only when the interaction IS the behavior: "send email to user" needs
verify(emailService).send(...). "calculate total" does not needverify(calculator).add(...)— check the result instead - Mock return values for queries, verify calls for commands (CQS principle applied to test doubles)
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 · 43 lines · 797 tokens per session scan A 0f564fdb9379
testing is a cursor rule published in the GitHub repository nedcodes-ok/cursor-doctor (9 stars, last pushed 5mo ago), licensed MIT. It adds 797 tokens to every session, about $0.0040 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.
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