11ai JavaScript ES2026 setup

Resolve the project root, package manager, target browser, server, worker, or embedded JavaScript runtimes, module format, source root, output policy, and existing checks before writing.

Version baseline: Target the stable ECMAScript 2026 edition. Prefer ES2026 APIs only after verifying native runtime support or an explicit transform and polyfill policy.

Gather first

Confirm compatibility targets, strictness policy, public entry points, test runner, and whether generated files are committed. Never invent ECMAScript support, module format, runtime globals, bundler behavior, or error-handling policy.

Install and configure

npm install --save-dev eslint
npx eslint --init

Use the repository package manager. Preview files and scripts before creating them, and extend rather than replace an active configuration.

Read references/setup.md for the standalone walkthrough, configuration decisions, and verification sequence.

Verify

npm run lint --if-present
npm test --if-present
npm run build --if-present

Exercise one narrow example in the real target and inspect emitted output. Do not weaken a check or patch generated files to make setup pass.

Guardrails

Never print or commit tokens, cookies, personal data, full request bodies, or server-only environment values. Ask before changing package manager, module format, public exports, output directories, or dependency versions. Report files, versions, targets, scripts, checks, and rollback.