Add allow option to no-nodejs-modules rule (fixes #452) (#509)

* Add `allow` option to `no-nodejs-modules` rule (fixes #452)

* Add test case

* Fix not working in Node v4

CHANGELOG.md

@@ -4,7 +4,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This change log adheres to standards from [Keep a CHANGELOG](http://keepachangelog.com).
 
 ## [Unreleased]
-
+- Added an `allow` option to [`no-nodejs-modules`] to allow exceptions ([#452], [#509]).
 
 ## [1.14.0] - 2016-08-22
 ### Added
@@ -290,6 +290,7 @@ for info on changes for earlier releases.
 [`prefer-default-export`]: ./docs/rules/prefer-default-export.md
 [`no-restricted-paths`]: ./docs/rules/no-restricted-paths.md
 
+[#509]: https://github.com/benmosher/eslint-plugin-import/pull/509
 [#503]: https://github.com/benmosher/eslint-plugin-import/pull/503
 [#499]: https://github.com/benmosher/eslint-plugin-import/pull/499
 [#461]: https://github.com/benmosher/eslint-plugin-import/pull/461
@@ -331,6 +332,7 @@ for info on changes for earlier releases.
 [#478]: https://github.com/benmosher/eslint-plugin-import/issues/478
 [#456]: https://github.com/benmosher/eslint-plugin-import/issues/456
 [#453]: https://github.com/benmosher/eslint-plugin-import/issues/453
+[#452]: https://github.com/benmosher/eslint-plugin-import/issues/452
 [#441]: https://github.com/benmosher/eslint-plugin-import/issues/441
 [#423]: https://github.com/benmosher/eslint-plugin-import/issues/423
 [#416]: https://github.com/benmosher/eslint-plugin-import/issues/416

docs/rules/no-nodejs-modules.md

@@ -2,6 +2,12 @@
 
 Forbid the use of Node.js builtin modules. Can be useful for client-side web projects that do not have access to those modules.
 
+### Options
+
+This rule supports the following options:
+
+- `allow`: Array of names of allowed modules. Defaults to an empty array.
+
 ## Rule Details
 
 ### Fail
@@ -24,6 +30,9 @@ import foo from './foo';
 var _ = require('lodash');
 var foo = require('foo');
 var foo = require('./foo');
+
+/* eslint import/no-nodejs-modules: ["error", {"allow": ["path"]}] */
+import path from 'path';
 ```
 
 ## When Not To Use It

src/rules/no-nodejs-modules.js

@@ -1,20 +1,23 @@
 import importType from '../core/importType'
 import isStaticRequire from '../core/staticRequire'
 
-function reportIfMissing(context, node, name) {
-  if (importType(name, context) === 'builtin') {
+function reportIfMissing(context, node, allowed, name) {
+  if (allowed.indexOf(name) === -1 && importType(name, context) === 'builtin') {
     context.report(node, 'Do not import Node.js builtin module "' + name + '"')
   }
 }
 
 module.exports = function (context) {
+  const options = context.options[0] || {}
+  const allowed = options.allow || []
+
   return {
     ImportDeclaration: function handleImports(node) {
-      reportIfMissing(context, node, node.source.value)
+      reportIfMissing(context, node, allowed, node.source.value)
     },
     CallExpression: function handleRequires(node) {
       if (isStaticRequire(node)) {
-        reportIfMissing(context, node, node.arguments[0].value)
+        reportIfMissing(context, node, allowed, node.arguments[0].value)
       }
     },
   }

tests/src/rules/no-nodejs-modules.js

@@ -26,6 +26,36 @@ ruleTester.run('no-nodejs-modules', rule, {
     test({ code: 'var foo = require("foo")'}),
     test({ code: 'var foo = require("./")'}),
     test({ code: 'var foo = require("@scope/foo")'}),
+    test({
+      code: 'import events from "events"',
+      options: [{
+        allow: ['events'],
+      }],
+    }),
+    test({
+      code: 'import path from "path"',
+      options: [{
+        allow: ['path'],
+      }],
+    }),
+    test({
+      code: 'var events = require("events")',
+      options: [{
+        allow: ['events'],
+      }],
+    }),
+    test({
+      code: 'var path = require("path")',
+      options: [{
+        allow: ['path'],
+      }],
+    }),
+    test({
+      code: 'import path from "path";import events from "events"',
+      options: [{
+        allow: ['path', 'events'],
+      }],
+    }),
   ],
   invalid: [
     test({
@@ -44,5 +74,12 @@ ruleTester.run('no-nodejs-modules', rule, {
       code: 'var fs = require("fs")',
       errors: [error('Do not import Node.js builtin module "fs"')],
     }),
+    test({
+      code: 'import fs from "fs"',
+      options: [{
+        allow: ['path'],
+      }],
+      errors: [error('Do not import Node.js builtin module "fs"')],
+    }),
   ],
 })