eslint-plugin-unicorn/rules/empty-brace-spaces.js

Various awesome ESLint rules

'use strict';
const {isOpeningBraceToken} = require('eslint-utils');
const {matches} = require('./selectors/index.js');

const MESSAGE_ID = 'empty-brace-spaces';
const messages = {
	[MESSAGE_ID]: 'Do not add spaces between braces.'
};

const selector = matches([
	'BlockStatement[body.length=0]',
	'ClassBody[body.length=0]',
	'ObjectExpression[properties.length=0]',
	// Experimental https://github.com/tc39/proposal-record-tuple
	'RecordExpression[properties.length=0]',
	// Experimental https://github.com/tc39/proposal-class-static-block
	'StaticBlock[body.length=0]'
]);

/** @param {import('eslint').Rule.RuleContext} context */
const create = context => {
	return {
		[selector](node) {
			const sourceCode = context.getSourceCode();
			const filter = node.type === 'RecordExpression' ?
				token => token.type === 'Punctuator' && (token.value === '#{' || token.value === '{|') :
				isOpeningBraceToken;
			const openingBrace = sourceCode.getFirstToken(node, {filter});
			const closingBrace = sourceCode.getLastToken(node);
			const [, start] = openingBrace.range;
			const [end] = closingBrace.range;
			const textBetween = sourceCode.text.slice(start, end);

			if (!/^\s+$/.test(textBetween)) {
				return;
			}

			return {
				loc: {
					start: openingBrace.loc.end,
					end: closingBrace.loc.start
				},
				messageId: MESSAGE_ID,
				fix: fixer => fixer.removeRange([start, end])
			};
		}
	};
};

module.exports = {
	create,
	meta: {
		type: 'layout',
		docs: {
			description: 'Enforce no spaces between braces.'
		},
		fixable: 'whitespace',
		messages
	}
};