shakaperf

How to drive shaka-perf twin-servers (the control + experiment Docker pair) from an agent — which subcommand to use for build, start containers, start the app, stop, run a command inside a side, or sync code changes. Bare `shaka-perf servers` is for humans (interactive menu); agents must call subcommands directly. Use whenever you need to bring twin-servers up, restart them after a change, or run something inside a container. Triggers include "servers", "twin servers", "ab servers", "control/experiment server", "run X in container", "ab tests failing".

Audit existing .abtest.ts files plus the latest `shaka-perf audit` results for anti-patterns, false-positive PASSes (blank/high-whitespace screenshots), and coverage gaps. Use whenever the user wants to review, audit, improve, or "assess quality" of AB tests — phrasings like "are my visreg tests any good?", "check the ab tests", "why is this test passing?", or "make these tests more reliable".

Crawl a website and auto-generate .abtest.ts files for shaka-perf visreg visual regression testing. Use this skill whenever the user wants to discover, generate, or scaffold AB tests for a URL — even if they just say "set up tests for localhost:3020", "generate tests for this site", or "create visreg tests".

Review/design guide for framework extension points in shaka-perf. When a primitive has variants (pipeline, stage, …), the variant must own its behaviour via mandatory factory options and the framework must call into it polymorphically. The only allowed name-keyed `switch` is the single deserialisation site that maps a persisted name back to a primitive instance. Use when adding a new pipeline/stage variant, adding an extension point, reviewing a PR that introduces variant-specific behaviour, or auditing a `switch (name)` that picks between behaviours.

Set up shaka-perf twin-servers — the Docker A/B testing infrastructure that runs your app twice (control vs experiment) so visreg/perf can compare two branches. Use this skill whenever the user wants to set up, configure, or debug twin-servers, "dockerize" their app for shaka-perf, write the twin-servers Dockerfile/Procfile/docker-compose, fill in the `twinServers` config, or get `shaka-perf servers` building and running — even if they just say "set up twin servers", "get the A/B servers running", or "make my app run under shaka-perf for perf testing".