eslint-plugin-baseline-js

Scope & Terms

What this plugin checks and how JS Syntax vs JS Builtins vs Web APIs.

Three surfaces of JavaScript

When we say “JavaScript”, we actually mean one of three surfaces. Knowing the difference makes configuration and detection much easier.

JS Syntax

Examples: nullish coalescing (a ?? b), optional catch binding, top‑level await, template literals
What it is: ECMAScript language syntax (operators, statements)
How we detect: delegate to community rules (eslint-plugin-es-x), ESLint core, and a few internal rules
In this plugin: always in scope, even with the “syntax only” setup

JS Builtins

Examples: BigInt64Array, Intl.Segmenter, Temporal, Math.sumPrecise (proposal)
What it is: the standard library (globals, namespaces, classes, methods)
How we detect: data‑driven (web‑features “JSBI” descriptors). Works without types for most patterns
In this plugin: enabled in recommended presets (includeJsBuiltins: { preset: 'auto' })

Web APIs

Examples: fetch, AbortSignal.any(), IntersectionObserver, Element.animate()
What it is: browser/host APIs (DOM, WebGL, media, sensors, …)
How we detect: data‑driven (web‑features API descriptors). Instance methods benefit from type info
In this plugin: enabled in recommended presets (includeWebApis: { preset: 'auto' }, or type‑aware for TS)

Extras

For detection mechanics and overall coverage, see the Coverage report.

Coverage

What’s covered, at a glance

Last updated on

What is eslint-plugin-baseline-js

✅ ESLint plugin that enforces the JavaScript Baseline across JS (Syntax / Builtins / Web APIs).

Best Practices

Flat Config recipes for running JS/CSS/HTML under one Baseline policy.

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