with-tests

A set of rules for finding, running, and understanding a project's automated tests. It explains how to locate test commands and interpret the test runner's output.

In plain words
What is it for?
Running tests, locating the right command and code path, investigating failures, and reporting test errors with relevant context.
Why use it?
It reduces guesswork when tests are stored behind project scripts or custom runners. It also helps turn bare error messages into useful explanations.

Cursor rule for Cursor

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 rules/zackiles/deno-kit/with-tests
Clone the repo
git clone --depth 1 https://github.com/zackiles/deno-kit

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 316 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00000 $0.00316
Opus 5 $0.00000 $0.00158
Sonnet 5 $0.00000 $0.00063
Haiku 4.5 $0.00000 $0.00032

Measured yesterday against content hash 6c18329a4753, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

with-tests 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.

.cursor/rules/with-tests.mdc · 15 lines

What it actually says

Steps To Running or Reading Tests

  1. Determine the commands, arguments, and path of the code file that runs the tests by searching for the nearest package file that typically will list the available test runners and commands. For example, this is often a package.json, deno.json file that exposes the projects scripts, and hopefully a set of test commands.

  2. Review the entry point of the test runner to understand what global utilities, patterns, strategies, logging, and high-level capabilities are implemented so you're able debug any issues with the tests if you run into any while running them.

  3. When errors occur always use all the information available to you, obvious or hidded, to contexualize any error messages you output to a user, or go retrieve more information to supplement with the error message or log.

CAUTION: HUMANS OFTEN DON'T FIND PLAIN LOG MESSAGES HELPFUL, AND THEY'LL PUNISH YOU IF YOU'RE NOT HELPFUL. ALWAYS SUPPLEMENT SUPPLEMENT PLAIN LOGS WITH OTHER CONTEXUAL DATA POINTS AND ANALYSIS UNLESS THE LOGS ARE ROBUST, AND FIND WAYS TO MAKE COMPLICATED LOGS SIMPLER. APPLY FORMATTING THAT MAKES LOGS EASY TO READ IN YOUR OUTPUT, SUCH AS PRETTY PRINTING, GROUPING, AND LABELING SO YOUR HUMAN WONT PUNISH YOU.

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 · 15 lines · 316 tokens per session scan A 6c18329a4753

Subscribe to this mod's changes

with-tests is a cursor rule published in the GitHub repository zackiles/deno-kit (3 stars, last pushed 5mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 316 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.