lwc-oss-safe-changes

name	lwc-oss-safe-changes
description	Safely implement or refactor LWC OSS code in this repo (LWR + Rollup targets) while preserving cross-target behavior across core extension, chat extension, and shared runtime modules.

LWC OSS Safe Changes

Use this skill when editing LWC components/modules under:

• packages/lwc/main/*
• packages/lwc/extension/*
• packages/lwc/applications/*
• packages/lwc/shared/*

Goal

Make LWC OSS changes that are small, target-aware, and regression-safe.

Repo-specific constraints

• This repo builds multiple targets (extension, extension-chat, workers, server/web).
• Shared LWC changes can impact both:
  • packages/extension/* (core extension)
  • packages/extension-chat/* (chat extension)

Golden rules

1. Prefer local edits over broad refactors.
2. Preserve backward-compatible defaults in shared components.
3. If behavior must differ by target, use explicit @api flags.
4. Do not degrade one target while fixing another.

Safe change patterns

1) Target-specific UI behavior

• Add optional API flags in shared components:
  • @api hideLlmSettingsCard = false
  • @api useInlineOnboarding = false
• Enable flags only from target-specific host templates.

2) State and events

• Keep public event contracts stable (detail shape + event name).
• Prefer additive event payload fields over breaking changes.

3) Component composition

• Keep role boundaries clear:
  • host component owns navigation/layout mode
  • shared component owns internal controls and emits events

Required verification

After LWC OSS edits:

1. Targeted lint/format:

npx eslint <changed .js/.ts files>
npx prettier --check <changed .html/.css/.js/.ts files>

2. Build matrix:

• If only target-local LWC changed, build that target.
• If shared LWC changed, build both:

npm run build:extension:main
npm run build:extension:chat:main

3. If shared module wiring/manifests changed:

npm run build:shared

Output checklist

• LWC files changed (by folder)
• Any target guard/flag added
• Verification commands and outcomes
• Residual risk (if e2e/manual not run)