Testing & Load

Pixelflux is tested at several levels — unit tests (in-memory), integration tests against a real Redis via Testcontainers, API contract tests (Hurl + OpenAPI), and load/benchmark tests (k6):

Load tests (k6)

health.js is a k6 load test for the HTTP server. It ramps virtual users up and down while reading the canvas and painting random pixels, and asserts latency and error-rate thresholds.

What it does

• Stages: 0→20 VUs over 10s, 20→50 VUs over 20s, 50→0 over 10s.
• Per iteration: GET /api/canvas, then POST /api/pixel with random x/y/color.
• Thresholds (the test fails if breached):
  • http_req_failed < 1% (error rate)
  • http_req_duration p95 < 200 ms

Run it

task bench

The task builds the release binary, boots the server, runs k6 against it, and stops the server afterwards.

To run it against an already-running server (local or remote), set BASE_URL:

BASE_URL=http://localhost:3000 k6 run load/health.js
# or against the deployed instance:
BASE_URL=https://your.domain.com k6 run load/health.js

Tuning

Adjust the stages (load profile) and thresholds (pass/fail criteria) at the top of health.js. Keep the thresholds realistic for the environment you test against — a remote cluster will have higher latency than localhost.