Lint Playground

LintPlayground — paste code, watch analysis light it up.

blog & long-formclientuiv1.0.0

Preview

Lint Playground — live renderblocks-lintplayground--default

Rendered from the story the storybook (a11y) CI gate runs axe against — the preview can't show something that hasn't been verified.

Install

Two equivalent paths — the URL works in any shadcn-CLI setup; the alias works once you've registered @interlace in your components.json.

Via shadcn URL
npx shadcn@latest add https://ds.interlace.tools/r/lint-playground.json
With the @interlace alias
npx shadcn@latest add @interlace/lint-playground

Behavior

What this component does — the keyboard path, the measured colour, the text equivalent and the states it can be in. Every figure below is read out of the test or the source that enforces it by scripts/build-behavior-map.mjs, so nothing here can outlive the gate that keeps it true.

Every semantic colour pair this component's own source uses, measured against the shipped hexes in all 4 theme × scheme combinations. The tightest is muted-foreground on muted at 7.34:1 (harbor · light), against a floor of 4.5:1.

Measured WCAG contrast ratios per token pair and theme
PairinterlacelightinterlacedarkharborlightharbordarkFloor
muted-foreground on mutedcopy on a muted surface8.81:110.48:17.34:18.64:14.5:1SC 1.4.3
destructive on backgrounddestructive tint on the page surface8.31:110.43:17.60:110.03:13.0:1SC 1.4.11
muted-foreground on backgroundsecondary copy9.41:111.32:17.82:19.52:14.5:1SC 1.4.3
destructive on carddestructive tint inside a card8.31:19.66:18.02:19.09:13.0:1SC 1.4.11
muted-foreground on cardsecondary copy in a card9.41:110.48:18.25:18.64:14.5:1SC 1.4.3
foreground on backgroundbody copy19.65:116.97:117.74:116.19:14.5:1SC 1.4.3

Text pairs are held to 4.5:1 (WCAG 2.2 SC 1.4.3); borders, rings and chart axes to 3:1 (SC 1.4.11 non-text). Bold is the worst cell in the row — the one a brand fork has to keep an eye on.

Where it renders, how narrow it survives, and whether its lines are inside the coverage gate — three answers a consumer needs before the paste, not after the bug.

Render boundary
'use client'

Hydrates. It brings JavaScript to any route that imports it — put the boundary here, not at the page.

Minimum viewport
none declared

No width floor: it takes the width it is given. Its container owns the layout question.

Coverage gate
100% × 4

Inside the v8 gate: lines 100, statements 100, functions 100, branches 100. A threshold under 100 only records how much you stopped caring, so there isn't one.

History

This component is at v1.0.0. The version is stamped as a banner into the file the install writes, so the copy in your tree says which one you have — compare it with the number above before deciding whether to re-run the install.

Unreleased1 entry

  • Addedminor

    CodeEditor + LintPlayground — paste code, watch analysis light it up **CodeEditor** (primitive): an editable code surface whose visual layer is DIAGNOSTICS, not syntax colour — the other half of the CodeBlock pair. The zero-sync layout trick: the textarea auto-grows (rows = line count) with soft wrap off, so a highlight bar for line N sits at a fixed offset computed from the line-height — no scroll listeners, nothing to drift; the leading-6/py-4 classes and the exported LINE_HEIGHT_PX/PAD_Y_PX constants are one test-pinned contract. Bars are aria-hidden position, never information, and severities differ by border, not hue alone. **LintPlayground** (pattern): editor + findings list + status around an INJECTED lint: (code) => Promise<PlaygroundDiagnostic[]> — the DS owns the surface and ships no linting dependency; the app brings a web worker bundling the real analyzer. Honesty rules, all test-locked: findings render as text first; stale results never paint (sequence-numbered, resolutions AND rejections); a failed analysis says "unknown, not clean" instead of an empty list; and the footer prints the privacy fact that makes pasting real code reasonable — analysis runs entirely in the reader's browser. Both join the coverage ledger at 100/100/100/100.

Import

Single named export.

Public API
import { LintPlayground } from '@/components/ui/patterns/lint-playground';

API reference

Parsed from the type declarations in the source — the same file the install writes into your tree, so this table can't drift from the component you get.

LintPlaygroundProps

Also accepts every <section> attribute.

PropTypeDescription
label*stringStable selector for E2E tests; consumer provides — no default (R5). */ 'data-testid': string; /** Accessible name for the editor inside.
initialCode*stringThe code the exhibit opens on — usually a vulnerable-by-design sample.
lint*(code: string) => Promise<readonly PlaygroundDiagnostic[]>The analyzer. Rejections render the failed state, never an empty list. Identity changes do NOT re-trigger analysis (the newest function is simply used on the next run) — an inline arrow in JSX is safe and will not flash "Analyzing…" on unrelated re-renders.
debounceMsnumberQuiet time after the last keystroke before analyzing. @default 300

Accessibility

Every story for this component is rendered headlessly and checked with axe-core (wcag2aa, wcag22aa, best-practice, ACT) on every PR. That gate has no continue-on-error, so what ships has zero known violations.

What follows is what static analysis can see. Axe cannot press a key and never sees an overlay open, so the operable-without-a-mouse claim lives in Behavior instead, where the keyboard path is replayed step by step.

Focus + keyboard behaviour
Native element semantics — no interaction layer to get wrong.
Focus ring (WCAG 2.2 SC 2.4.13)
Not focusable — no focus indicator required.
Reduced motion
No animation to gate.
ARIA in the source
  • role="status"
  • aria-label

Examples

2 more states from the same story file.

R-rule compliance

Every primitive in @interlace/ui models to the portable 26-rule floor enforced by the componentApi ESLint preset. The cells below pin exactly where each rule applies in this file.

RuleConceptWhere
R5testid required, no default`'data-testid': string`
R6data-slot on every part`"lint-playground" / "-status" / "-findings" / "-footer"`
R11Composition over kind-propsthe analyzer is injected, not enumerated
R16No internal couplingrenders CodeEditor, brings no linter
R24Product-neutralno plugin names, no product copy
R25Client componentdebounce + async state

Dependencies

Base UI primitive
Native / no Base UI dependency
Lucide icons
none
NPM dependencies
none

Source

The full implementation — components/ui/patterns/lint-playground.tsx once installed.

216 lines · TypeScript
'use client';

import * as React from 'react';

// @interlace/lint-playground v1.0.0 — Interlace design system.
// Docs, props and live preview: https://ds.interlace.tools/c/lint-playground
// What changed since: https://ds.interlace.tools/c/lint-playground#history
// Generated banner — keep it, the upgrade diff reads this version.

import { cn } from '@/lib/utils';
import { CodeEditor, type CodeEditorDiagnostic } from '@/components/ui/code-editor';

/**
 * LintPlayground — paste code, watch analysis light it up.
 *
 * ## The seam: the consumer brings the analyzer
 *
 * `lint` is an injected async function. The DS owns the surface —
 * editor, findings list, status — and stays free of any linting
 * dependency; the app owns HOW linting happens (a web worker bundling

…196 more lines…

Registry JSON

The raw registry record — what the shadcn CLI fetches.