flaker-setup

name	flaker-setup
description	Set up @mizchi/flaker on a new repository. Use when the user asks to introduce flaker, configure flaker.toml, integrate flaker into GitHub Actions, or "start using flaker on this project". Encodes the declarative apply-based onboarding flow for @mizchi/flaker 0.7.0+ (declarative apply model).

flaker setup skill

@mizchi/flaker (0.7.0+) is a test-intelligence CLI with a declarative apply model: flaker.toml describes the desired state, and flaker apply reconciles the repo to that state by running collect / calibrate / cold-start run / quarantine apply in the right order based on current DB state and repo probe. Callers do not memorize the sequence.

Always read the canonical checklist first. It lives next to this skill in the plugin:

• Plugin-relative: ${CLAUDE_PLUGIN_ROOT}/docs/new-project-checklist.ja.md or ${CLAUDE_PLUGIN_ROOT}/docs/new-project-checklist.md
• GitHub: https://github.com/mizchi/flaker/blob/main/docs/new-project-checklist.ja.md or https://github.com/mizchi/flaker/blob/main/docs/new-project-checklist.md

If both are unreachable, fall back to the procedure below.

When this skill applies

• "新しいプロジェクトに flaker を入れたい"
• "flaker.toml を作って"
• "GitHub Actions に flaker を組み込んで"
• "this project should use flaker"
• "flaker のセットアップ手順を教えて"

Mental model: desired state + reconciler

1. User writes flaker.toml (gates, profiles, [promotion] thresholds, [quarantine].auto).
2. flaker plan shows what apply would do right now.
3. flaker apply executes the plan (idempotent; safe to re-run).
4. flaker status shows drift vs [promotion] thresholds.

The Day 1 flow is flaker init → flaker doctor → flaker apply → flaker status. The deprecated imperative chain (init → collect → calibrate → run) still works via compat shims but is a migration-only concern — do not use it in new projects.

Minimal declarative flaker.toml

[repo]
owner = "your-org"
name = "your-repo"

[adapter]
type = "playwright"

[runner]
type = "playwright"
command = "pnpm exec playwright test"
flaky_tag_pattern = "@flaky"

[affected]
resolver = "workspace"

[quarantine]
auto = false              # Day 1 recommended: keep false until history accumulates;
                          # flip to true in Week 1-2 once `flaker status` drift shows moderate+ confidence.
flaky_rate_threshold_percentage = 30
min_runs = 10

[profile.local]
strategy = "affected"
max_duration_seconds = 60
fallback_strategy = "weighted"
skip_flaky_tagged = true

[profile.ci]
strategy = "hybrid"
sample_percentage = 30
adaptive = true
skip_flaky_tagged = true

[profile.scheduled]
strategy = "full"

# [promotion] is OPTIONAL — defaults (matched_commits_min=20, FNR<=5%, correlation>=95%,
# holdout_fnr<=10%, data_confidence_min="moderate") apply when omitted.

flaker init generates a starter toml including [profile.*] defaults; expect to edit [affected].resolver before the first flaker apply.

Decision points to confirm before touching files

Ask the user (or infer from package.json / pnpm-workspace.yaml / repo layout) — do NOT guess silently:

1. Adapter — playwright | vitest | jest | junit. Look at package.json devDependencies and existing test files. Default to vitest for TS libraries, playwright for e2e, junit for non-Node.
2. Runner — vitest | playwright | jest | actrun. Usually matches the adapter. actrun wraps a GitHub Actions workflow file when local execution should mirror CI exactly.
3. Resolver — workspace | glob | bitflow | git. Pick workspace if pnpm-workspace.yaml or package.json workspaces exists. Pick glob for legacy single-package repos (then create flaker.affected.toml). Pick bitflow only if the repo already uses bitflow.
4. CI history availability — does the repo already have GitHub Actions runs? Either way, flaker apply handles it: with no history it skips calibrate and runs a cold-start gate; with history it pulls + calibrates + applies quarantine.
5. GITHUB_TOKEN scope — gh auth status must show actions:read. If missing, the user runs gh auth refresh -s actions:read themselves.

Phase order

Day 0   prerequisites           5 min   node>=24, pnpm>=10, gh auth, git remote
Day 1   install + init          10 min  pnpm add -D @mizchi/flaker → init → doctor
Day 1   first apply              5 min   flaker plan → flaker apply → flaker status
Day 3   package.json scripts     5 min   flaker:plan, flaker:apply, flaker:status, flaker:run:*
Day 5   Actions integration     15 min   cron `flaker apply` + PR advisory `flaker run --gate merge`
Week 1  daily observation        -      flaker status (drift → promotion-ready signal)
Week 2-4 promote to required     -      drift == ready, remove continue-on-error

Day 2 and Day 4 are intentionally empty — apply is idempotent, so there is no forced action between the Day 1 bootstrap and the Day 3 / Day 5 integration steps. Run flaker apply whenever you want (manually or in cron); skip days if nothing changed.

Never skip the continue-on-error: true on the first PR job. The CI job becomes a required check ONLY after flaker status drift reports ready (all 5 [promotion] thresholds met). Promoting too early causes false negatives that erode developer trust.

Day 1 commands (copy-paste ready)

# 0. prerequisites
node --version && pnpm --version && git remote -v && gh auth status

# 1. install
pnpm add -D @mizchi/flaker

# 2. init (init now writes [profile.*] defaults)
pnpm flaker init --adapter <adapter> --runner <runner>

# 3. doctor
pnpm flaker doctor

# 4. edit [affected].resolver in flaker.toml (workspace | glob | bitflow)

# 5. preview + converge
export GITHUB_TOKEN=$(gh auth token)   # optional if no CI history yet
pnpm flaker plan
pnpm flaker apply
pnpm flaker status

What flaker apply does

The planner produces a PlannedAction[] based on current state:

Action	Condition
collect_ci --days 30	GITHUB_TOKEN present. Pulls new CI runs.
calibrate	data.confidence is moderate or high. Tunes [sampling].
cold_start_run (iteration gate)	No local history yet. Seeds the first local sample.
quarantine_apply	[quarantine].auto = true AND history is usable. Applies the current quarantine plan.

When actions don't apply (e.g. no GITHUB_TOKEN on a brand-new repo), apply silently skips them. It is safe to run anywhere in the lifecycle.

package.json scripts to add

{
  "scripts": {
    "flaker": "flaker",
    "flaker:plan": "flaker plan",
    "flaker:apply": "flaker apply",
    "flaker:status": "flaker status",
    "flaker:run:iteration": "flaker run --gate iteration",
    "flaker:run:release": "flaker run --gate release",
    "flaker:eval": "flaker status --markdown",
    "flaker:doctor": "flaker doctor"
  }
}

GitHub Actions snippets

PR advisory (MUST be continue-on-error: true for the first 2-4 weeks):

- name: Run tests via flaker (advisory)
  run: pnpm flaker run --gate merge
  continue-on-error: true
  env:
    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Nightly apply (single scheduled cron replaces the old collect + run pair):

- run: pnpm flaker apply
  env:
    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
- run: pnpm flaker status --markdown > .artifacts/flaker-status.md

Promotion criteria for required check

Only promote flaker run --gate merge from advisory to required when flaker status drift shows ready (all 5 [promotion] thresholds met), or equivalently when flaker status --gate merge --detail --json reports:

• Matched commits ≥ 20
• False negative rate ≤ 5%
• Pass correlation ≥ 95%
• Holdout FNR ≤ 10%
• Data confidence: moderate or high

The thresholds live in [promotion] of flaker.toml; defaults match the above. Override in config if the project needs stricter or looser gating.

The simplest readout is flaker status — the drift section shows ready or lists unmet thresholds.

If the user wants to gate sooner, push back: empirically less than 20 matched commits gives unstable readings.

Pitfalls (encountered in real dogfood)

Symptom	Cause	Fix
flaker.toml uses deprecated keys	Config from 0.1.x or earlier	Apply rename table from docs/how-to-use.md#config-migration
Config file not found	Wrong cwd	cd to repo root containing flaker.toml
flaker apply aborts with GITHUB_TOKEN missing	Planner included collect_ci but env var absent	export GITHUB_TOKEN=$(gh auth token) and re-run
actrun runner requires [runner.actrun] workflow	Missing actrun config	Add [runner.actrun] workflow = ".github/workflows/<file>.yml"
hybrid selects 0 tests	Resolver not configured	Set [affected].resolver
flaker apply stops after collect_ci	Calibrate or cold-start failed	Inspect the ok/fail lines; fix and re-run apply (idempotent)
flaker status drift: data_confidence unmet	< ~10 matched commits	Wait, or run more flaker apply after CI accumulates
Tests timeout in parallel	DuckDB single-writer	Serialize commands sharing the same data.duckdb
dist/moonbit/flaker.js missing	Custom build environment	Should not happen with npm install — investigate package.json files:

Anti-patterns

• Do not edit config keys to old names ("looks cleaner") — the loader hard-fails on legacy keys.
• Do not enable [profile.ci] adaptive = true until at least 30 commits of history exist. Adaptive sampling needs FNR data to converge.
• Do not set holdout_ratio > 0.2 — wastes runner time.
• Do not skip flaker apply and hand-tune [sampling] — the calibrated values outperform manual settings in 90% of cases.
• Do not make the PR job required before flaker status drift reports ready.
• Do not use deprecated aliases in new scripts — setup init, exec run, collect ci, collect calibrate, analyze kpi, analyze eval, debug doctor, quarantine suggest/apply, policy quarantine/check/report, gate review/history/explain all print deprecation warnings in 0.7.0 and will be removed in 0.8.0. Use the primary commands: flaker init, flaker run, flaker apply, flaker status, flaker doctor, flaker explain, flaker query, etc.

Reference docs (in this plugin)

All paths relative to ${CLAUDE_PLUGIN_ROOT} of the installed plugin, or in the flaker repo on GitHub.

• README.md — feature overview, install, Quick Start (Path 1 / Path 2), canonical command forms table
• docs/new-project-checklist.ja.md / docs/new-project-checklist.md — the canonical full checklist (this skill is its action-oriented summary)
• docs/usage-guide.ja.md / docs/usage-guide.md — user-facing entrypoint after setup
• docs/operations-guide.ja.md / docs/operations-guide.md — maintainer / CI owner entrypoint
• docs/how-to-use.md / docs/how-to-use.ja.md — full command reference including the flaker plan / flaker apply chapter and #config-migration table
• docs/contributing.md — sibling dogfood, MoonBit/TS fallback, build internals
• CHANGELOG.md — version history, breaking changes per release