---

name: scaffold-cli-command locale: caveman-ultra source_locale: en source_commit: 82c77053 fence_basis_commit: 82c77053 translator: "Julius Brussee homage — caveman" translation_date: "2026-05-03" description: > Scaffold new Commander.js CLI cmd → opts, action handler, 3 output modes (human|quiet|JSON), opt ceremony variant. Cmd naming, opt design, shared ctx, err handling, integ tests. Use → add cmd to existing CLI, design new CLI, standardize cmd structure. license: MIT allowed-tools: Read Write Edit Bash Grep Glob metadata: author: Philipp Thoss version: "1.0" domain: cli complexity: intermediate language: TypeScript tags: - cli - commander - nodejs - terminal - command-pattern

Scaffold a CLI Command

Add cmd → Commander.js CLI w/ consistent opts, 3 output modes, integ tests.

Use When

• Add cmd to existing Commander.js CLI
• Design multi-cmd CLI from scratch
• Standardize cmd structure → all same patterns
• Add ceremony variant → warm narrative output

In

• Required: Cmd name + verb (gather, audit, sync)
• Required: What cmd does (1 sentence)
• Required: CLI entry path (cli/index.js)
• Optional: Ceremony variant needed?
• Optional: Custom opts beyond standard
• Optional: Subcmd args (<name>|[names...])

Do

Step 1: Cmd Name + Category

Verb communicates action. Group:

Category	Verbs	Pattern
CRUD	install, uninstall, list, search	Operates on content
Lifecycle	init, sync, audit	Manages project state
Ceremony	gather, scatter, tend, campfire	Warm narrative output

Conventions:

• Single verb (not install-skill — opts specify what)
• Lowercase, no hyphens in cmd name
• Positional: <required>|[optional]|[variadic...]

program
  .command('gather <name>')
  .description('Gather a team around the campfire')

→ Cmd name, desc, positional args defined.

If err: verb overlaps existing → compose (add opt to existing) or differentiate in desc.

Step 2: Opts

Standard set + cmd-specific.

Standard (as needed):

  .option('-n, --dry-run', 'Preview without making changes')
  .option('-q, --quiet', 'Suppress human-readable output')
  .option('--json', 'Output as JSON')
  .option('-f, --framework <id>', 'Target specific framework')
  .option('-g, --global', 'Use global scope')
  .option('--scope <scope>', 'Scope: project, workspace, global', 'project')
  .option('--source <path>', 'Path to tool root directory')

Cmd-specific — only what needed:

  .option('--ceremonial', 'Show each item arriving individually')
  .option('--only <items>', 'Comma-separated subset to include')
  .option('-y, --yes', 'Skip confirmation prompts')

Rules:

• Short flags (-n) for frequent
• Long (--dry-run) for clarity
• Default vals as 3rd arg
• Booleans for toggles

→ Complete opt chain w/ standard + custom.

If err: too many opts (>8) → split into subcmds or group related.

Step 3: Action Handler

Consistent pattern:

.action(async (name, options) => {
  // 1. Get shared context (registries, adapters, paths)
  const ctx = getContext(options);

  // 2. Resolve what to operate on
  const items = resolveItems(ctx, name, options);
  if (!items || items.length === 0) {
    reporter.error('Nothing found.');
    process.exit(1);
  }

  // 3. Preview if dry-run
  if (options.dryRun) reporter.printDryRun();

  // 4. Execute the operation
  const results = await executeOperation(items, ctx, options);

  // 5. Output results (3 modes)
  if (options.json) {
    console.log(JSON.stringify(results, null, 2));
  } else if (options.quiet) {
    reporter.printResults(results);
  } else {
    printHumanOutput(results, options);
  }
})

getContext() shared helper centralizes:

• Root dir detection
• Registry loading
• Framework detection|explicit
• Scope resolution

→ Handler follows 5-step: ctx → resolve → preview → exec → output.

If err: cmd doesn't fit resolve-then-exec (purely informational like detect) → simplify: ctx → compute → output.

Step 4: 3 Output Modes

Default (human):

Installing 3 item(s) to Claude Code...

  + create-skill [claude-code] .claude/skills/create-skill
  + write-tests  [claude-code] .claude/skills/write-tests
  = commit-changes [claude-code] (skipped)

  2 installed, 1 skipped

Quiet (--quiet): Standard reporter — concise lines w/ status icons (+, -, =, !), no ceremony, no decoration.

JSON (--json):

{
  "command": "install",
  "items": 3,
  "installed": 2,
  "skipped": 1,
  "failed": 0
}

Pattern:

if (options.json) {
  console.log(JSON.stringify(data, null, 2));
  return;
}
if (options.quiet) {
  reporter.printResults(results);
  return;
}
// Default: human-readable output
printHumanReadable(results, options);

→ All 3 modes useful. JSON parseable. Quiet concise. Default informative.

If err: no meaningful JSON (detect) → skip + document why.

Step 5: Ceremony Variant (Optional)

For cmds benefiting from warm narrative:

if (options.json) {
  ceremonyReporter.printJson(data);
} else if (options.quiet) {
  reporter.printResults(results);
} else {
  ceremonyReporter.printArrival({
    teamId: name,
    agents,
    results: { installed, skipped, failed },
    ceremonial: options.ceremonial || false,
  });
}

Voice rules:

1. Present tense, active ("mystic arrives", not "was installed")
2. No exclamation
3. Metaphor → jargon ("practices" not "deps")
4. Failures honest, not catastrophic ("a spark was lost")
5. Closing reflects state ("The fire burns.")
6. No emoji — Unicode glyphs (✦ ◉ ◎ ○ ✗)
7. Every word carries info

See design-cli-output skill for terminal patterns.

→ Ceremony follows voice rules → warm informative narratives.

If err: ceremony forced or doesn't add info → skip. Not every cmd needs.

Step 6: Errs + Edge Cases

// Unknown item
if (!item) {
  reporter.error(`Unknown: ${name}. Use 'tool list' to browse.`);
  process.exit(1);
}

// Confirmation for destructive actions
if (!options.yes && !options.quiet && !options.dryRun) {
  const answer = await askYesNo('Proceed?');
  if (!answer) {
    console.log('  Cancelled.');
    return;
  }
}

// State validation
if (!state.fires[name]) {
  reporter.error(`Not active. Nothing to remove.`);
  process.exit(1);
}

Err design:

• Msgs suggest corrective action
• process.exit(1) for unrecoverable
• Confirm for destructive (bypass --yes)
• Dry-run always succeeds (no confirm block)

→ All err paths helpful. Destructive needs confirm.

If err: confirm prompts break scripting → ensure --yes + --quiet bypass both.

Step 7: Integ Tests

import { describe, it, after } from 'node:test';
import assert from 'node:assert/strict';
import { execSync } from 'child_process';

const CLI = 'node cli/index.js';
function run(args) {
  return execSync(`${CLI} ${args}`, { encoding: 'utf8', timeout: 10000 });
}

describe('new-command', () => {
  after(() => { /* cleanup created files/state */ });

  it('dry-run shows preview', () => {
    const out = run('new-command arg --dry-run');
    assert.match(out, /DRY RUN/);
  });

  it('--json outputs valid JSON', () => {
    const out = run('new-command arg --json');
    const start = out.indexOf('{');
    const data = JSON.parse(out.slice(start));
    assert.equal(data.command, 'new-command');
  });

  it('rejects unknown input', () => {
    assert.throws(() => run('new-command nonexistent'), /Unknown/);
  });
});

See test-cli-application for comprehensive patterns.

→ ≥3 tests: dry-run, JSON, err. More for complex.

If err: execSync timeout → ↑timeout or check for interactive prompts blocking.

Check

• Cmd registered in entry + --help
• Standard opts (--dry-run, --quiet, --json) work
• Default human + informative
• JSON valid + parseable
• Err msgs suggest fix
• Destructive needs confirm (bypass --yes)
• ≥3 integ tests pass
• Cmd follows getContext → resolve → exec → output

Traps

• Forget JSON: Machine consumers (scripts, CI) need structured. Always impl --json.
• Confirm blocks scripts: Any prompt hangs non-interactive. Always provide --yes for destructive + --quiet suppresses.
• Inconsistent exit codes: Use process.exit(1) all errs. Tools check exit first.
• Opts no defaults: --scope etc → sensible defaults so users don't specify each time.
• Ceremony in quiet mode: --quiet = "min output for machines". Ceremony leak → scripts break.

→

• build-cli-plugin — build adapter/plugin cmds operate on
• test-cli-application — comprehensive testing beyond Step 7
• design-cli-output — terminal design all verbosity
• install-almanac-content — well-structured CLI cmd example