eslint-plugin-unicorn/rules/require-number-to-fixed-digits-argument.js

Various awesome ESLint rules

'use strict';
const {methodCallSelector} = require('./selectors/index.js');
const {appendArgument} = require('./fix/index.js');

const MESSAGE_ID = 'require-number-to-fixed-digits-argument';
const messages = {
	[MESSAGE_ID]: 'Missing the digits argument.'
};

const mathToFixed = methodCallSelector({
	name: 'toFixed',
	length: 0
});

/** @param {import('eslint').Rule.RuleContext} context */
const create = context => {
	const sourceCode = context.getSourceCode();
	return {
		[mathToFixed](node) {
			const [
				openingParenthesis,
				closingParenthesis
			] = sourceCode.getLastTokens(node, 2);

			return {
				loc: {
					start: openingParenthesis.loc.start,
					end: closingParenthesis.loc.end
				},
				messageId: MESSAGE_ID,
				/** @param {import('eslint').Rule.RuleFixer} fixer */
				fix: fixer => appendArgument(fixer, node, '0', sourceCode)
			};
		}
	};
};

module.exports = {
	create,
	meta: {
		type: 'suggestion',
		docs: {
			description: 'Enforce using the digits argument with `Number#toFixed()`.'
		},
		fixable: 'code',
		messages
	}
};