Crussell/frontend/eslint.a11y.config.js

import { fileURLToPath } from 'node:url';
import { includeIgnoreFile } from '@eslint/compat';
import js from '@eslint/js';
import svelte from 'eslint-plugin-svelte';
import { defineConfig } from 'eslint/config';
import globals from 'globals';
import ts from 'typescript-eslint';
import svelteConfig from './svelte.config.js';

const gitignorePath = fileURLToPath(new URL('./.gitignore', import.meta.url));

// Svelte 5 a11y checking — no separate svelte/a11y-* rules exist in
// eslint-plugin-svelte v3.20.0.  All a11y validation is built into the
// Svelte 5 compiler itself (42 checks covering alt-text, ARIA, keyboard
// interaction, semantic HTML, tabindex, roles, labels, etc.).  The
// svelte/valid-compile rule below surfaces EVERY compiler warning — including
// all compiler-level a11y diagnostics — as ESLint errors.
//
// See node_modules/svelte/src/compiler/warnings.js for the full list of
// a11y_* warning codes.  No separate eslint-plugin-a11y or jsx-a11y rules
// are needed since the Svelte 5 compiler covers them natively.

export default defineConfig(
	includeIgnoreFile(gitignorePath),
	js.configs.recommended,
	...ts.configs.recommended,
	...svelte.configs.recommended,
	{
		languageOptions: {
			globals: { ...globals.browser, ...globals.node }
		}
	},
	{
		files: ['**/*.svelte', '**/*.svelte.ts', '**/*.svelte.js'],
		languageOptions: {
			parserOptions: {
				projectService: true,
				extraFileExtensions: ['.svelte'],
				parser: ts.parser,
				svelteConfig
			}
		}
	},
	{
		name: 'svelte:a11y:rules',
		files: ['**/*.svelte', '**/*.svelte.ts', '**/*.svelte.js'],
		rules: {
			// Surface ALL Svelte 5 compiler warnings as errors — this catches every
			// built-in a11y check (a11y_missing_attribute, a11y_click_events_have_key_events,
			// a11y_no_static_element_interactions, a11y_role_has_required_aria_props,
			// a11y_label_has_associated_control, a11y_media_has_caption, … 42 total).
			// No warning filter is applied, so every diagnostic is reported.
			'svelte/valid-compile': 'error',

			// Require explicit type attribute on <button> elements
			'svelte/button-has-type': 'error',

			// Require rel="noopener noreferrer" with target="_blank"
			'svelte/no-target-blank': 'error'
		}
	}
);