Use ESLint Stylistic without hard wrapping

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+
+[*.{js,json}]
+indent_style = tab
+indent_size = tab
+tab_width = 4
+trim_trailing_whitespace = true

.github/workflows/eslint.yaml

@@ -0,0 +1,25 @@
+name: ESLint
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: "24"
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run ESLint
+        timeout-minutes: 5
+        run: npm run format:check

Syntax.js

@@ -237,12 +237,12 @@ export class Syntax {
 		} catch (error) {
 			throw new LanguageLoadError(name, path, {cause: error});
 		}
-		
+
 		// If the module exports a register function, call it with this instance
 		if (typeof module.default === 'function') {
 			module.default(this);
 		}
-		
+
 		// After calling register, aliases have been registered. Re-resolve the name:
 		let resolvedName = this.#aliases[name] || name;
 		return loader.get(resolvedName);

Syntax/CodeElement.js

@@ -83,7 +83,7 @@ export class CodeElement extends HTMLElement {
 
 	constructor() {
 		super();
-		
+
 		/**
 		 * A promise that resolves when the current highlighting attempt completes.
 		 * Check `highlighted` before using line measurement APIs.
@@ -150,26 +150,26 @@ export class CodeElement extends HTMLElement {
 	 */
 	getLineBoundingClientRect(lineNumber) {
 		if (!this.#shadow) return null;
-		
+
 		const code = this.#shadow.querySelector('code');
 		if (!code) return null;
-		
+
 		const lines = code.children;
 		if (lineNumber < 1 || lineNumber > lines.length) return null;
-		
+
 		return lines[lineNumber - 1].getBoundingClientRect();
 	}
-	
+
 	/**
 	 * Get the total number of rendered lines.
 	 * @returns {number} The line count, or 0 if not yet rendered.
 	 */
 	get lineCount() {
 		if (!this.#shadow) return 0;
-		
+
 		const code = this.#shadow.querySelector('code');
 		if (!code) return 0;
-		
+
 		return code.children.length;
 	}
 
@@ -180,7 +180,7 @@ export class CodeElement extends HTMLElement {
 	get highlighted() {
 		return this.#highlighted;
 	}
-	
+
 	connectedCallback() {
 		// Detect if we're inside a <pre> element and set wrap attribute
 		if (this.parentElement?.tagName === 'PRE') {

Syntax/Rule.js

@@ -134,14 +134,14 @@ export class Rule {
 	 * Create a conditional matcher that selects a rule based on another capture group.
 	 * Tests a condition capture group against patterns to determine which rule to apply
 	 * to a content capture group.
-	 * 
+	 *
 	 * @param {number} conditionIndex - Capture group index to test against patterns
 	 * @param {number} contentIndex - Capture group index containing content to match
 	 * @param {Array<{pattern?: RegExp, ...rule}>} conditions - Array of condition objects. Each can have:
 	 *   - pattern: RegExp to test against the condition group (optional - if omitted, acts as fallback)
 	 *   - Any rule properties (language, type, etc.) to apply when pattern matches
 	 * @returns {Function} A matches function for use in language rules
-	 * 
+	 *
 	 * @example
 	 * // Script tags with type-based language selection
 	 * language.push({
@@ -152,7 +152,7 @@ export class Rule {
 	 *     {language: 'javascript'} // Fallback for no type or unknown types
 	 *   ])
 	 * });
-	 * 
+	 *
 	 * @example
 	 * // Code fence with language specifier
 	 * language.push({
@@ -163,7 +163,7 @@ export class Rule {
 	 *     {language: 'plaintext'} // Fallback
 	 *   ])
 	 * });
-	 * 
+	 *
 	 * @example
 	 * // Conditional type based on prefix
 	 * language.push({
@@ -201,7 +201,7 @@ export class Rule {
 
 			// Build syntax tree or create match based on rule properties
 			const offset = match.index + match[0].indexOf(content);
-			
+
 			if (ruleProps.language) {
 				return [
 					await Language.buildTree(

bin/syntax-ast.js

@@ -4,26 +4,26 @@ import Syntax from '../Syntax.js';
 
 async function main() {
 	const args = process.argv.slice(2);
-	
+
 	if (args.length < 2) {
 		console.error('Usage: syntax-ast <language> <code>');
 		console.error('Example: syntax-ast javascript "const x = 1;"');
 		process.exit(1);
 	}
-	
+
 	const [languageName, code] = args;
-	
+
 	const syntax = new Syntax();
-	
+
 	try {
 		const language = await syntax.getLanguage(languageName);
 		const matches = await language.getMatches(syntax, code);
-		
+
 		console.log('Language:', languageName);
 		console.log('Code:', JSON.stringify(code));
 		console.log('\nMatches:', matches.length);
 		console.log('─'.repeat(80));
-		
+
 		for (const match of matches) {
 			const text = code.substring(match.offset, match.offset + match.length);
 			console.log(`[${match.type}] @${match.offset}..${match.offset + match.length} (${match.length} chars)`);
@@ -32,7 +32,7 @@ async function main() {
 				console.log(`  Children: ${match.children.length}`);
 			}
 		}
-		
+
 	} catch (error) {
 		console.error('Error:', error.message);
 		process.exit(1);

eslint.config.js

@@ -0,0 +1,44 @@
+import stylistic from '@stylistic/eslint-plugin';
+
+export default [
+	{
+		plugins: {
+			'@stylistic': stylistic
+		},
+		rules: {
+			'@stylistic/array-bracket-spacing': ['error', 'never'],
+			'@stylistic/arrow-parens': ['error', 'as-needed'],
+			'@stylistic/arrow-spacing': 'error',
+			'@stylistic/block-spacing': ['error', 'always'],
+			'@stylistic/brace-style': [
+				'error',
+				'1tbs',
+				{allowSingleLine: true}
+			],
+			'@stylistic/comma-dangle': ['error', 'never'],
+			'@stylistic/comma-spacing': 'error',
+			'@stylistic/computed-property-spacing': ['error', 'never'],
+			'@stylistic/eol-last': ['error', 'always'],
+			'@stylistic/function-call-spacing': ['error', 'never'],
+			'@stylistic/indent': ['error', 'tab', {SwitchCase: 1}],
+			'@stylistic/key-spacing': 'error',
+			'@stylistic/keyword-spacing': 'error',
+			'@stylistic/no-mixed-spaces-and-tabs': 'error',
+			'@stylistic/no-trailing-spaces': 'error',
+			'@stylistic/object-curly-spacing': ['error', 'never'],
+			'@stylistic/quotes': ['error', 'single', {avoidEscape: true}],
+			'@stylistic/rest-spread-spacing': ['error', 'never'],
+			'@stylistic/semi': ['error', 'always'],
+			'@stylistic/semi-spacing': 'error',
+			'@stylistic/space-before-blocks': 'error',
+			'@stylistic/space-before-function-paren': [
+				'error',
+				{anonymous: 'always', asyncArrow: 'always', named: 'never'}
+			],
+			'@stylistic/space-in-parens': ['error', 'never'],
+			'@stylistic/space-infix-ops': 'error',
+			'@stylistic/space-unary-ops': 'error',
+			'@stylistic/template-curly-spacing': ['error', 'never']
+		}
+	}
+];