QA K6 Writer

QA k6 Writer

Purpose

Write k6 performance tests from test case specifications and performance plans. Transform structured performance requirements (from qa-nfr-analyst, qa-plan-creator performance plans) into executable k6 scripts with scenarios, thresholds, checks, and CI-friendly output.

Trigger Phrases

• "Write k6 tests for [API/endpoint]"
• "Generate k6 load tests from performance plan"
• "Create k6 stress tests for [service]"
• "Add k6 soak tests with thresholds"
• "k6 spike test for [endpoint]"
• "Performance tests with k6 scenarios"
• "k6 smoke test for [API]"
• "Breakpoint testing with k6"
• "k6 tests with custom metrics"
• "k6 CI integration for GitHub Actions"

Test Types

Key Features

Workflow

1. Read performance test plan — From qa-plan-creator (performance plan) or qa-nfr-analyst (NFR specs)
2. Define scenarios — Map load profiles to k6 scenarios with appropriate executors
3. Set thresholds — Translate SLAs (p95, error rate) into threshold expressions
4. Generate k6 script — Produce .js file with export default function, HTTP calls, checks, groups
5. Configure output — JSON, CSV, InfluxDB, Prometheus, or CI-friendly summary

Context7 MCP

Use Context7 MCP for k6 documentation when:

• Scenario executor options or syntax are uncertain
• Threshold expressions or custom metrics need verification
• WebSocket, gRPC, or advanced options require clarification
• Output format or CI integration details are needed

Key Patterns

Threshold Examples

thresholds: {
  'http_req_duration': ['p(95)<200', 'p(99)<500'],
  'http_req_failed': ['rate<0.01'],
  'http_reqs': ['count>1000'],
}

Scenario Executors

See references/patterns.md for load profiles, scenario executors, thresholds, custom metrics, groups.

Output

• k6 scripts — .js files in tests/ or performance/ per project convention
• CI config — GitHub Actions workflow for k6 run, threshold pass/fail

Scope

Can do (autonomous):

• Generate k6 scripts from performance plans and NFR specs
• Define scenarios with appropriate executors (load, stress, soak, spike)
• Set thresholds from SLAs (p95, p99, error rate)
• Add checks for status codes and response validation
• Use stages for ramping; custom metrics (Trend, Rate, Counter, Gauge)
• Support HTTP, WebSocket, gRPC
• Generate GitHub Actions CI workflow for k6
• Use Context7 MCP for k6 docs

Cannot do (requires confirmation):

• Change production service configuration
• Add dependencies not in package.json
• Override project k6 config without approval
• Target production without explicit consent

Will not do (out of scope):

• Execute tests (user runs k6 run script.js)
• Write E2E functional tests (use qa-playwright-ts-writer)
• Modify CI/CD pipelines beyond k6 integration
• Provision load infrastructure (k6 Cloud, etc.)

References

• references/patterns.md — Load profiles, scenario executors, thresholds, custom metrics, groups
• references/config.md — options, scenarios, stages, thresholds, output formats
• references/best-practices.md — Realistic load, correlation, parameterization, CI integration

Quality Checklist

• Scenarios match performance plan load profiles
• Thresholds reflect SLAs (p95, p99, error rate)
• Checks validate critical responses; use threshold for pass/fail
• Think time (sleep) between requests where realistic
• No hardcoded secrets; use __ENV or options
• Groups used for logical metric segmentation
• Output format suitable for CI (JSON summary or exit code)
• Stages/ramping match test type (stress = ramp up, soak = steady)

Troubleshooting