Add import-style rule

docs/rules/no-direct-import.md

@@ -0,0 +1,22 @@
+# Do not import modules directly
+
+Do not import the core Node.js modules directly.
+
+## Fail
+
+```js
+const util = require('util');
+
+import util from 'util';
+
+import * as util from 'util';
+```
+
+
+## Pass
+
+```js
+const {promisify} = require('util');
+
+import {promisify} from 'util';
+```

index.js

@@ -51,6 +51,7 @@ module.exports = {
 				'unicorn/prefer-add-event-listener': 'error',
 				'unicorn/prefer-exponentiation-operator': 'error',
 				'unicorn/no-console-spaces': 'error',
+				'unicorn/no-direct-import': 'error',
 				'unicorn/no-unreadable-array-destructuring': 'error',
 				'unicorn/no-unused-properties': 'off',
 				'unicorn/prefer-node-append': 'error',

readme.md

@@ -68,6 +68,7 @@ Configure it in `package.json`.
 			"unicorn/no-unsafe-regex": "off",
 			"unicorn/prefer-add-event-listener": "error",
 			"unicorn/no-console-spaces": "error",
+			"unicorn/no-direct-import": "error",
 			"unicorn/no-unreadable-array-destructuring": "error",
 			"unicorn/no-unused-properties": "off",
 			"unicorn/prefer-node-append": "error",
@@ -104,6 +105,7 @@ Configure it in `package.json`.
 - [prefer-add-event-listener](docs/rules/prefer-add-event-listener.md) - Prefer `addEventListener` over `on`-functions. *(fixable)*
 - [prefer-exponentiation-operator](docs/rules/prefer-exponentiation-operator.md) - Prefer the exponentiation operator over `Math.pow()` *(fixable)*
 - [no-console-spaces](docs/rules/no-console-spaces.md) - Do not use leading/trailing space between `console.log` parameters. *(fixable)*
+- [no-direct-import](docs/rules/no-direct-import.md) - Do not import the core Node.js modules directly.
 - [no-unreadable-array-destructuring](docs/rules/no-unreadable-array-destructuring.md) - Disallow unreadable array destructuring.
 - [no-unused-properties](docs/rules/no-unused-properties.md) - Disallow unused object properties.
 - [prefer-node-append](docs/rules/prefer-node-append.md) - Prefer `append` over `appendChild`. *(fixable)*

rules/no-direct-import.js

@@ -0,0 +1,77 @@
+'use strict';
+const getDocsUrl = require('./utils/get-docs-url');
+
+const defaults = [
+	'lodash',
+	'underscore',
+	'util'
+];
+
+// This part handles the VariableDeclarator
+const isObjectPattern = node => node.id.type === 'ObjectPattern';
+
+const isImportingDirect = callExpression => {
+	if (callExpression.callee.name === 'require') {
+		if (defaults.includes(callExpression.arguments[0].value)) {
+			return true;
+		}
+
+		return false;
+	}
+
+	return false;
+};
+
+const importDirectVariable = (context, node, callExpression) => {
+	if (isObjectPattern(node)) {
+		return true;
+	}
+
+	if (isImportingDirect(callExpression)) {
+		context.report({
+			node,
+			message: 'Do not reference directly'
+		});
+	}
+};
+
+// This part handles the ImportSpecifiers
+const isImportSpecifier = node => node.specifiers[0].type === 'ImportSpecifier';
+
+const isImportRestricted = node => {
+	if (defaults.includes(node.source.value)) {
+		return true;
+	}
+
+	return false;
+};
+
+const importDirectDeclaration = (context, node) => {
+	if (isImportSpecifier(node)) {
+		return true;
+	}
+
+	if (isImportRestricted(node)) {
+		context.report({
+			node,
+			message: 'Do not reference directly'
+		});
+	}
+};
+
+const create = context => {
+	return {
+		VariableDeclarator: node => importDirectVariable(context, node, node.init),
+		ImportDeclaration: node => importDirectDeclaration(context, node)
+	};
+};
+
+module.exports = {
+	create,
+	meta: {
+		docs: {
+			url: getDocsUrl(__filename)
+		},
+		fixable: 'code'
+	}
+};

test/no-direct-import.js

@@ -0,0 +1,38 @@
+import test from 'ava';
+import avaRuleTester from 'eslint-ava-rule-tester';
+import rule from '../rules/no-direct-import';
+
+const ruleTester = avaRuleTester(test, {
+	parserOptions: {
+		sourceType: 'module'
+	}
+});
+
+const error = {
+	ruleId: 'no-direct-import',
+	message: 'Do not reference directly'
+};
+
+ruleTester.run('no-direct-import', rule, {
+	valid: [
+		'const {promisify} = require(\'util\');',
+		'import {promisify} from \'util\';',
+		'const file = require(\'unrestricted\')',
+		'import file from \'unrestricted\'',
+		'const util = myFunction(\'util\')'
+	],
+	invalid: [
+		{
+			code: 'const util = require(\'util\');',
+			errors: [error]
+		},
+		{
+			code: 'import util from \'util\';',
+			errors: [error]
+		},
+		{
+			code: 'import * as util from \'util\';',
+			errors: [error]
+		}
+	]
+});