perf-lint

import { Aside, Badge } from ‘@astrojs/starlight/components’;

perf-lint is the only dedicated linter for performance test scripts across JMeter, k6, and Gatling. It enforces 53 rules covering correctness, performance anti-patterns, and best practices.

Tier	Rules	Price
Community (free)	18 rules	Free — `pip install perf-lint-tool`
Pro	18 + 17 extended = 35 rules	£9/month
Team	18 + 35 extended = 53 rules + team config	£29/month

Installation

pip install perf-lint-tool
perf-lint --version

Requires Python 3.8+.

Basic Usage

# Check a script
perf-lint check my-test.jmx
perf-lint check my-script.js
perf-lint check MySimulation.scala

# Auto-fix supported rules
perf-lint check my-test.jmx --fix

# Output as SARIF (for GitHub code scanning)
perf-lint check my-test.jmx --format sarif --output results.sarif

# Output as JSON
perf-lint check my-test.jmx --format json

Exit Codes

Code	Meaning
`0`	No errors (warnings/info may be present)
`1`	One or more errors found
`2`	Tool error (file not found, parse failure, etc.)

Use exit code 1 to fail CI pipelines on errors.

Configuration

Create .perf-lint.yml in your project root:

version: "1.0"

rules:
  # Disable a specific rule
  JMX001: off

  # Change severity
  JMX010: warn   # default: error

  # Rule with config
  JMX042:
    severity: warn
    max_vus: 500

ignore:
  - "tests/legacy/**"
  - "**/*.bak.jmx"

# Pro/Team: sync rule config from perf-lint API
api_sync:
  enabled: true
  # API key from perf-ecosystem.yml or set directly:
  api_key: "${PERF_LINT_API_KEY}"

Rule Categories

JMeter Rules (JMX prefix)

Rule	Severity	Description
JMX001	WARN	Thread group uses “Forever” loop
JMX010	ERROR	HTTP sampler missing explicit timeout
JMX015	ERROR	Hardcoded hostname — use variables
JMX020	WARN	No assertions on any sampler
JMX025	WARN	Think time missing between requests
JMX030	ERROR	CSV Data Set Config references missing file
JMX035	WARN	Regex extractor with greedy match
JMX040	INFO	Result tree listener left enabled
JMX042	INFO	Parameterise VU count
JMX050	ERROR	Non-standard response code handling

Full rule reference: perflint.martkos-it.co.uk

k6 Rules (K6 prefix)

Rule	Severity	Description
K6001	ERROR	`sleep()` missing between requests
K6005	WARN	No threshold defined
K6010	ERROR	Hardcoded URL
K6015	WARN	`check()` result not validated
K6020	WARN	No gracefulStop defined
K6025	ERROR	`open()` called inside VU function

Gatling Rules (GTL prefix)

Rule	Severity	Description
GTL001	WARN	Pause time missing
GTL005	ERROR	No assertions defined
GTL010	WARN	Constant load profile — consider ramp
GTL015	ERROR	Hardcoded base URL

GitHub Action

Zero-configuration lint step for GitHub Actions:

- name: Lint performance scripts
  uses: markslilley/perf-lint-action@v1
  with:
    path: tests/performance/
    tool: jmeter          # jmeter | k6 | gatling | auto
    fail-on: error        # error | warn | info

Available on GitHub Marketplace.

perf-lint API (Hosted)

The hosted API at perflint.martkos-it.co.uk accepts script uploads and returns lint results. Useful for web dashboards or CI systems without Python.

curl -X POST https://perflint.martkos-it.co.uk/api/lint \
  -H "X-API-Key: ${PERF_LINT_API_KEY}" \
  -F "file=@my-test.jmx" \
  -F "tool=jmeter"

Rate limits: Free 50 scans/month · Pro 500 scans/month · Team unlimited.

See perf-lint API reference for full endpoint documentation.

Pro/Team Features

35 extended rules (Pro) — deeper analysis: correlator pattern detection, resource leak detection, protocol-specific anti-patterns
53 rules total (Team) — all extended rules plus team-specific checks
Team configuration — share .perf-lint.yml across projects via the API; changes propagate without re-deploying
SARIF integration — upload results to GitHub Advanced Security for in-PR annotations

Ecosystem Integration

When perf-ecosystem.yml is present with services.perf_lint_api configured:

Auto-syncs rule configuration from the team config store
perf-migrator auto-lints converted scripts if integrations.migrator_validate: true