test-cli-application
About
This skill provides integration testing for Node.js CLI applications using the built-in node:test module. It includes helpers for executing commands, asserting outputs, verifying filesystem state, and handling cleanup and error cases. Use it to add robust tests to existing CLIs, validate new commands, or set up continuous integration pipelines.
Quick Install
Claude Code
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Documentation
Test CLI App
Integration tests via built-in node:test + execSync.
Use When
- Add tests to existing CLI
- Test new cmd
- Verify adapter/plugin behavior across frameworks
- Setup CI validating CLI correctness
- Catch regressions after CLI internal refactor
In
- Required: Path to CLI entry (
cli/index.js) - Required: Cmds to test
- Optional: Framework adapters to test (dry-run)
- Optional: Cleanup reqs (files/symlinks created)
Do
Step 1: Setup Test Infra
import { describe, it, before, after } from 'node:test';
import assert from 'node:assert/strict';
import { execSync } from 'child_process';
import { existsSync, rmSync } from 'fs';
import { resolve } from 'path';
const CLI = 'node cli/index.js';
const ROOT = process.cwd();
function run(args) {
return execSync(`${CLI} ${args}`, {
cwd: ROOT,
encoding: 'utf8',
timeout: 10000,
});
}
Design decisions:
node:testbuilt-in — no test runner depexecSyncruns CLI as subprocess → tests actual binary, not internals- 10s timeout prevents hanging on prompts
encoding: 'utf8'→ strings for regex- All paths relative to
ROOTfor reproducibility
Got: Test file imports from node:test, working run() helper.
If err: node:test not avail → Node < 18. Upgrade | polyfill.
Step 2: Smoke Tests
Verify CLI starts, parses args, expected output shapes:
describe('meta', () => {
it('shows version', () => {
const out = run('--version');
assert.match(out, /\d+\.\d+\.\d+/);
});
it('shows help with all commands', () => {
const out = run('--help');
assert.match(out, /install/);
assert.match(out, /list/);
assert.match(out, /detect/);
});
});
describe('registry', () => {
it('list shows expected counts', () => {
const out = run('list --domains');
assert.match(out, /\d+ domains/);
});
it('search finds known items', () => {
const out = run('search "docker"');
assert.match(out, /result\(s\) for "docker"/);
});
it('search returns 0 for nonsense', () => {
const out = run('search "xyzzy-nonexistent"');
assert.match(out, /0 result/);
});
});
Smoke patterns:
--version+--helpalways work- Registry loading validates data integrity
- Search w/ known + unknown terms
Got: Smoke tests confirm CLI functional, data loaded.
If err: Registry counts change often → use \d+ not hardcoded #s.
Step 3: Lifecycle Tests
Create → verify → delete sequences w/ cleanup:
describe('install', () => {
const testPath = resolve(ROOT, '.agents/skills/commit-changes');
after(() => {
// Always clean up, even if tests fail
try { rmSync(testPath); } catch {}
try { rmSync(resolve(ROOT, '.agents/skills'), { recursive: true }); } catch {}
try { rmSync(resolve(ROOT, '.agents'), { recursive: true }); } catch {}
});
it('dry-run does not create files', () => {
const out = run('install commit-changes --dry-run');
assert.match(out, /DRY RUN/);
assert.ok(!existsSync(testPath));
});
it('installs creates the target', () => {
run('install commit-changes');
assert.ok(existsSync(testPath));
});
it('skips already installed', () => {
const out = run('install commit-changes');
assert.match(out, /skipped/);
});
it('uninstall removes the target', () => {
run('uninstall commit-changes');
assert.ok(!existsSync(testPath));
});
});
Cleanup rules:
- Use
after()notafterEach()— lifecycle tests build on each other - Wrap cleanup in
try/catch— must not fail suite - Clean leaf → root (file → parent → grandparent)
- Modifies shared state (symlinks, configs) → restore
Got: Tests run in sequence within describe, cleanup runs even on fail.
If err: Tests run parallel (non-default in node:test) → force sequential w/ { concurrency: 1 }.
Step 4: Dry-Run Tests Per Adapter
Test each adapter's target path w/o changes:
describe('adapter: cursor (dry-run)', () => {
it('targets .cursor/skills/ path', () => {
const out = run('install commit-changes --framework cursor --dry-run');
assert.match(out, /\.cursor\/skills/i);
});
});
describe('adapter: copilot (dry-run)', () => {
it('targets .github/ path', () => {
const out = run('install commit-changes --framework copilot --dry-run');
assert.match(out, /\.github/i);
});
});
Pattern scales to any adapters. Each test:
--frameworkbypasses auto-detection--dry-run→ no files created- Asserts target path appears in output
Got: 1 describe per adapter, each w/ ≥ path assertion.
If err: Adapter doesn't exist in proj → fails w/ "Unknown framework". Correct — adapter tests should only exist for implemented.
Step 5: Err Case Tests
describe('errors', () => {
it('rejects unknown items', () => {
assert.throws(
() => run('install nonexistent-skill-xyz'),
/No matching items|Unknown/,
);
});
it('rejects unknown framework', () => {
assert.throws(
() => run('install commit-changes --framework nonexistent'),
/Unknown framework/,
);
});
it('handles missing state gracefully', () => {
assert.throws(
() => run('scatter nonexistent-team'),
/not burning|Unknown/,
);
});
});
Err testing patterns:
assert.throwscatches non-zero exits fromexecSync- Regex match on err msg (captured from stderr)
- Test "item not found" + "invalid option" errs
- Verify err msgs suggest corrective actions
Got: All err paths → non-zero exits + helpful msgs.
If err: execSync throws on non-zero. Err's stderr | stdout has msg. Check error.stdout if regex doesn't match.
Step 6: JSON Output Tests
describe('json output', () => {
it('campfire --json outputs valid JSON', () => {
const out = run('campfire --json');
const data = JSON.parse(out);
assert.ok(typeof data.totalTeams === 'number');
assert.ok(Array.isArray(data.fires));
});
it('gather --dry-run --json outputs structured data', () => {
const out = run('gather tending --dry-run --json');
// JSON may follow a DRY RUN header — extract from first '{'
const jsonStart = out.indexOf('{');
assert.ok(jsonStart >= 0, 'Should contain JSON');
const data = JSON.parse(out.slice(jsonStart));
assert.equal(data.team, 'tending');
});
});
JSON testing gotchas:
- Some cmds prefix JSON w/ human text (DRY RUN header)
- Extract JSON by first
{ - Validate structure (key presence, types), not exact values
- Counts may change as content added
Got: JSON output parseable + contains expected keys.
If err: JSON.parse fails → cmd may mix human text + JSON. Fix cmd → pure JSON in --json mode | extract substring.
Step 7: Cleanup + State Restoration
describe('stateful commands', () => {
const stateDir = resolve(ROOT, '.agent-almanac');
after(() => {
// Remove state file created by tests
try { rmSync(stateDir, { recursive: true }); } catch {}
});
// Tests that create/modify state...
});
// Restore symlinks that destructive tests may remove
describe('destructive tests', () => {
after(() => {
// Restore symlinks that scatter/uninstall removed
const skills = ['heal', 'meditate', 'remote-viewing'];
for (const skill of skills) {
const link = resolve(ROOT, `.claude/skills/${skill}`);
if (!existsSync(link)) {
try {
execSync(`ln -s ../../skills/${skill} ${link}`, { cwd: ROOT });
} catch {}
}
}
});
});
State restoration rules:
- State files (
.agent-almanac/state.json) → cleaned after tests - Symlinks removed by
scatter/uninstall→ restored - Manifest (
agent-almanac.yml) created byinit→ removed - Order:
after()runs reverse declaration order → declare restore hooks last
Got: Suite leaves proj in same state found.
If err: CI reports leftover files → add cleanup to after(). Use git status after to detect leaked state.
Check
- Test file runs
node --test cli/test/cli.test.js - All pass (0 fails)
- Smoke tests cover
--version,--help, registry loading - Lifecycle: create → verify → delete w/ cleanup
- ≥1 adapter dry-run test per implemented adapter
- Err cases test non-zero exits w/ msg matching
- JSON tests parse actual output (not mocked)
- After hooks restore all modified state
Traps
- Hardcoded counts: Registry totals change. Use
\d+regex | read dynamic vs329 skills. - Tests dep on order:
node:testruns suites in declaration order default, but within suite may not. Lifecycle suites (create → verify → delete) within singledescribefor guarantee. - Missing cleanup on fail: Test fails mid-lifecycle →
after()still runs. Throw inbefore()→ subsequent +after()may not. Keepbefore()minimal. - Interactive prompts hang: Confirmation prompts hang
execSync. Pipeecho y || ensure--yesalways passed. - Real installs in CI: Tests creating in
.claude/skills/|.agents/skills/modify working tree. CI may fail on "dirty WD" checks. Always clean.
→
scaffold-cli-command— build cmds these tests verifybuild-cli-plugin— build adapters tested in Step 4design-cli-output— output patterns tests assert against
GitHub Repository
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