html-closing-bracket-spacing.ts

import { createRule } from '../utils/index.js';
import type { AST } from 'svelte-eslint-parser';

export default createRule('html-closing-bracket-spacing', {
	meta: {
		docs: {
			description: "require or disallow a space before tag's closing brackets",
			category: 'Stylistic Issues',
			conflictWithPrettier: true,
			recommended: false
		},
		schema: [
			{
				type: 'object',
				properties: {
					startTag: {
						enum: ['always', 'never', 'ignore']
					},
					endTag: {
						enum: ['always', 'never', 'ignore']
					},
					selfClosingTag: {
						enum: ['always', 'never', 'ignore']
					}
				},
				additionalProperties: false
			}
		],
		messages: {
			expectedSpace: "Expected space before '>', but not found.",
			unexpectedSpace: "Expected no space before '>', but found."
		},
		fixable: 'whitespace',
		type: 'layout'
	},
	create(ctx) {
		const options = {
			startTag: 'never',
			endTag: 'never',
			selfClosingTag: 'always',
			...ctx.options[0]
		};
		const src = ctx.sourceCode;

		/**
		 * Returns true if string contains newline characters
		 */
		function containsNewline(string: string): boolean {
			return string.includes('\n');
		}

		/**
		 * Report
		 */
		function report(node: AST.SvelteStartTag | AST.SvelteEndTag, shouldHave: boolean) {
			const tagSrc = src.getText(node);
			const match = /(\s*)\/?>$/.exec(tagSrc);

			const end = node.range[1];
			const start = node.range[1] - match![0].length;
			const loc = {
				start: src.getLocFromIndex(start),
				end: src.getLocFromIndex(end)
			};

			ctx.report({
				loc,
				messageId: shouldHave ? 'expectedSpace' : 'unexpectedSpace',
				*fix(fixer) {
					if (shouldHave) {
						yield fixer.insertTextBeforeRange([start, end], ' ');
					} else {
						const spaces = match![1];

						yield fixer.removeRange([start, start + spaces.length]);
					}
				}
			});
		}

		return {
			'SvelteStartTag, SvelteEndTag'(node: AST.SvelteStartTag | AST.SvelteEndTag) {
				const tagType =
					node.type === 'SvelteEndTag'
						? 'endTag'
						: node.selfClosing
							? 'selfClosingTag'
							: 'startTag';

				if (options[tagType] === 'ignore') return;

				const tagSrc = src.getText(node);
				const match = /(\s*)\/?>$/.exec(tagSrc);
				if (containsNewline(match![1])) return;

				if (options[tagType] === 'always' && !match![1]) {
					report(node, true);
				} else if (options[tagType] === 'never' && match![1]) {
					report(node, false);
				}
			}
		};
	}
});