Guidelines for creating and testing Bash shell scripts in a repository's scripts/ directory. It specifies file locations, executable scripts, test naming, and the Bach framework used to check commands.

Use it to write Bash scripts, create their unit tests, run all script tests, or run one script test in the project's environment.

It gives shell scripts and their tests a consistent structure, making them easier to run and less likely to test the wrong command behavior.

How nerds-odd-e/doughnut configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to nerds-odd-e/doughnut. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/nerds-odd-e/doughnut/main/.agents/skills/script/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/nerds-odd-e/doughnut

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/nerds-odd-e/doughnut/script/github.svg)](https://agentmods.dev/skills/nerds-odd-e/doughnut/script)

Your own site

<a href="https://agentmods.dev/skills/nerds-odd-e/doughnut/script"><img src="https://agentmods.dev/badge/skills/nerds-odd-e/doughnut/script/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/nerds-odd-e/doughnut/script"><img src="https://agentmods.dev/badge/skills/nerds-odd-e/doughnut/script.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 20 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 564 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00020	$0.00564
Opus 5.5	$0.00008	$0.00226
Sonnet 5.5	$0.00004	$0.00113
Haiku 4.5	$0.00002	$0.00056

Measured 1mo ago against content hash cf8619332971, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

script 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.

.agents/skills/script/SKILL.md · 78 lines

How it starts

The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Shell Script Development

Script Location

Place scripts in the scripts/ directory
Use descriptive names with .sh extension
Make scripts executable: chmod +x scripts/script_name.sh

Unit Testing

Test Framework

Use Bach testing framework for shell script unit tests
Bach is located at scripts/test/vendor/bach.sh
Bach requires Bash 4.3+ (available in nix environment)

Test File Structure

Test files should be in scripts/test/ directory
Use .test extension (e.g., scripts/test/run.sh.test)
Test files must be executable

Writing Tests

Source Bach framework:

source "$(dirname "$0")/vendor/bach.sh"

Create test functions with test- prefix:

test-my-feature() {
    # Test implementation
}

Create assertion functions with -assert suffix:

test-my-feature-assert() {
    @out "expected output"
}

Bach uses dry-run testing - it compares commands executed in test functions with expected commands in assert functions

Running Tests

Run all tests: bash scripts/test/run_all_script_tests.sh
Run individual test: bash scripts/test/script_name.test
In nix environment: ./scripts/run.sh bash scripts/test/run_all_script_tests.sh

Test Requirements

All scripts in scripts/ should have corresponding tests in scripts/test/
Tests are automatically discovered and run in CI
Tests must pass before merging

CURSOR_DEV Mode Behavior

When scripts are run with CURSOR_DEV=true nix develop -c <command>, the nix shell hook (scripts/nix_shell_hook.sh) should:

Output only a one-liner: <<running within nix env>> at the beginning
Suppress all other output: No log messages, environment info, or setup messages should appear
Preserve command output: The actual command's stdout/stderr should be displayed normally
Show errors only: If something goes wrong during setup, errors should still be visible

This ensures that when running commands via CURSOR_DEV=true nix develop -c, users see only:

The one-liner <<running within nix env>>
The command's actual output

Read the full file on GitHub · 78 lines

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.

1mo ago First seen · 78 lines · 20 tokens per session scan A cf8619332971

Subscribe to this mod's changes

script is a skill published in the GitHub repository nerds-odd-e/doughnut (50 stars, last pushed today), licensed MIT. It adds 20 tokens to every session and 564 once invoked, about $0.0001 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 2026-09-17.

Testing Unit testing

test-master

Generates test files, creates mocking strategies, analyzes code coverage, designs test architectures, and produces test plans and defect reports across functional, performance, and security testing disciplines. Use when writing unit tests, integration tests, or E2E tests; creating test strategies or automation…

Jeffallan/claude-skills · 104 tokens

migrate-xunit-to-xunit-v3

Migrate .NET test projects from xUnit.net v2 to xunit.v3 and fix v3 breaks. Use for package/CPM conversion, OutputType=Exe, preserving the VSTest or MTP runner (including projects currently using YTest.MTP.XUnit2), incompatible TFMs, async void tests, string-to-Type attributes, custom Fact/Theory/BeforeAfterTest…

dotnet/skills · 149 tokens

doughnut: Skill for Claude Code