eslint-plugin-z8/index.js

module.exports = {
	rules: {
		'no-spaces-in-conditionals': {
			meta: {
				docs: {
					description: 'Disallow spaces in conditionals',
					category: 'Z8 Stylistic Issues',
					recommended: true,
				},
				fixable: 'code',
				schema: [],
			},
			create: function (context) {
				return {
					IfStatement: function (node) {
						const tokens = context.getSourceCode().getTokens(node);
						const firstToken = tokens[0];
						const secondToken = tokens[1];

						if (
							firstToken.type === 'Keyword' &&
							firstToken.value === 'if' &&
							secondToken.type === 'Punctuator' &&
							secondToken.value === '(' &&
							secondToken.range[0] - firstToken.range[1] > 0
						) {
							context.report({
								node: node,
								message: 'Do not use spaces between \'if\' and its condition',
							});
						}
					},
				};
			},
		},
		'no-strict-equality': {
			meta: {
				docs: {
					description: 'Disallow strict equality operator',
					category: 'Z8 Stylistic Issues',
					recommended: true,
				},
				fixable: 'code',
				schema: [],
			},
			create: function (context) {
				return {
					BinaryExpression: function (node) {
						if (node.operator === '===') {
							context.report({
								node: node,
								message: 'Avoid using strict equality operator \'===\' (use loose equality operator \'==\' instead)',
							});
						}
					},
				};
			},
		},
		'no-double-quotes': {
			meta: {
				docs: {
					description: 'Disallow double quotes',
					category: 'Z8 Stylistic Issues',
					recommended: true,
				},
				fixable: 'code',
				schema: [],
			},
			create: function (context) {
				return {
					Literal: function (node) {
						if (typeof node.value === 'string' && node.raw.includes('"')) {
							context.report({
								node: node,
								message: 'Avoid using double quotes (use single quotes instead)',
							});
						}
					},
				};
			},
		},
		'no-arrow-functions': {
			meta: {
				docs: {
					description: 'Disallow arrow functions',
					category: 'Z8 Stylistic Issues',
					recommended: true,
				},
				fixable: 'code',
				schema: [],
			},
			create: function (context) {
				return {
					ArrowFunctionExpression: function (node) {
						context.report({
							node: node,
							message: 'Avoid using arrow functions',
						});
					},
				};
			},
		},
		'no-function-declaration': {
			meta: {
				docs: {
					description: 'Disallow function declaration',
					category: 'Z8 Stylistic Issues',
					recommended: true,
				},
				fixable: 'code',
				schema: [],
			},
			create: function (context) {
				return {
					FunctionDeclaration: function (node) {
						context.report({
							node: node,
							message: 'Use function expression instead of function declaration',
						});
					},
					VariableDeclarator: function (node) {
						if (
							node.init &&
							node.init.type === 'FunctionExpression' &&
							node.init.id &&
							node.init.id.type === 'Identifier' &&
							node.id &&
							node.id.type === 'Identifier' &&
							node.init.id.name === node.id.name
						) {
							context.report({
								node: node,
								message: 'Use function expression instead of function declaration',
							});
						}
					},
				};
			},
		},
	},
};