CLI Testing Patterns

A skill for systematically testing command-line tools and scripts. It covers discovering available commands, checking help text, testing options and errors, verifying exit codes, and validating output.

In plain words
What is it for?
Use it when testing shell scripts, command-line programs, build tools, or other terminal interfaces, especially around changed functionality.
Why use it?
It provides a repeatable way to find incorrect behavior and unclear command interfaces, including cases ordinary smoke tests may overlook.

Skill for Claude CodeCodex

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 skills/tommymorgan/claude-plugins/cli-testing-patterns
Any agent
npx skills add tommymorgan/claude-plugins --skill cli-testing-patterns
Clone the repo
git clone --depth 1 https://github.com/tommymorgan/claude-plugins

Made for: Claude Code, Codex.

Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,982 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. 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 $0.00053 $0.01982
Opus 5 $0.00026 $0.00991
Sonnet 5 $0.00011 $0.00396
Haiku 4.5 $0.00005 $0.00198

Measured yesterday against content hash 7ef7b95f3b46, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

CLI Testing Patterns scanned grade C with 1 finding 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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

rm -rf "$TMPDIR"
tommymorgan/testing/skills/cli-testing-patterns/SKILL.md · 383 lines

How it starts

The opening of the file, as written. The whole thing — 383 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLI Testing Patterns

Purpose

Provide systematic patterns for autonomous command-line tool exploratory testing. Guide agents through comprehensive CLI testing including help discovery, option validation, error handling checks, exit code verification, and output correctness testing.

Core Testing Methodology

Systematic CLI Testing Approach

Test command-line tools using a structured approach:

  1. Discovery: Find command and understand its options
  2. Basic smoke test: Verify command runs
  3. Help validation: Check help text completeness
  4. Option testing: Test all flags and arguments
  5. Error handling: Test edge cases and invalid inputs
  6. Output validation: Verify correctness and formatting
  7. Scoped comprehensive testing: Focus on changed areas

CLI Discovery Methods

Identify command to test from context:

Script path: ./scripts/build.sh Binary name: mycommand Package.json script: npm run test System command: git status

Verify command exists:

which mycommand
command -v mycommand
[ -f ./script.sh ] && echo "exists"

Help Text Discovery

Common Help Patterns

Try these flags to discover usage:

command --help
command -h
command help
command

Parse Help Output

Extract from help text:

  • Available options/flags
  • Required vs optional arguments
  • Expected input formats
  • Subcommands (if applicable)
  • Usage examples

Example help parsing:

Usage: deploy [options] <environment>

Options:
  -v, --verbose    Enable verbose output
  -d, --dry-run    Show what would be deployed
  --config <file>  Use custom config

Identifies:
- Required: <environment>
- Optional flags: -v, -d, --config
- Config file option

Smoke Testing

Basic Execution Tests

Test command works at all:

# Version check
command --version
command -v

# No arguments (if allowed)
command

# Help (should never error)
command --help

Verify:

  • Command executes without crashing
  • Returns appropriate exit code
  • Produces expected output or error

Read the full file on GitHub · 383 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 383 lines · 53 tokens per session scan C 7ef7b95f3b46

Subscribe to this mod's changes

CLI Testing Patterns is a skill published in the GitHub repository tommymorgan/claude-plugins (4 stars, last pushed 1mo ago), licensed MIT. It adds 53 tokens to every session and 1,982 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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