Support allow option in no-unassigned-import, fix #671

CHANGELOG.md

@@ -6,6 +6,7 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 ## [Unreleased]
 ### Added
 - Add `filePath` into `parserOptions` passed to `parser` ([#839], thanks [@sompylasar])
+- Add `allow` option to [`no-unassigned-import`] to allow for files that match the globs ([#671], [#737], thanks [@kevin940726]).
 
 ## [2.3.0] - 2017-05-18
 ### Added
@@ -390,6 +391,7 @@ for info on changes for earlier releases.
 [`no-anonymous-default-export`]: ./docs/rules/no-anonymous-default-export.md
 
 [#742]: https://github.com/benmosher/eslint-plugin-import/pull/742
+[#737]: https://github.com/benmosher/eslint-plugin-import/pull/737
 [#712]: https://github.com/benmosher/eslint-plugin-import/pull/712
 [#685]: https://github.com/benmosher/eslint-plugin-import/pull/685
 [#680]: https://github.com/benmosher/eslint-plugin-import/pull/680
@@ -446,6 +448,7 @@ for info on changes for earlier releases.
 [#157]: https://github.com/benmosher/eslint-plugin-import/pull/157
 [#314]: https://github.com/benmosher/eslint-plugin-import/pull/314
 
+[#671]: https://github.com/benmosher/eslint-plugin-import/issues/671
 [#660]: https://github.com/benmosher/eslint-plugin-import/issues/660
 [#653]: https://github.com/benmosher/eslint-plugin-import/issues/653
 [#627]: https://github.com/benmosher/eslint-plugin-import/issues/627
@@ -583,3 +586,4 @@ for info on changes for earlier releases.
 [@giodamelio]: https://github.com/giodamelio
 [@ntdb]: https://github.com/ntdb
 [@ramasilveyra]: https://github.com/ramasilveyra
+[@kevin940726]: https://github.com/kevin940726

docs/rules/no-unassigned-import.md

@@ -6,11 +6,24 @@ With both CommonJS' `require` and the ES6 modules' `import` syntax, it is possib
 
 This rule aims to remove modules with side-effects by reporting when a module is imported but not assigned.
 
+### Options
+
+This rule supports the following option:
+
+`allow`: An Array of globs. The files that match any of these patterns would be ignored/allowed by the linter. This can be useful for some build environments (e.g. css-loader in webpack).
+
+Note that the globs start from the where the linter is executed (usually project root), but not from each file that includes the source. Learn more in both the pass and fail examples below.
+
+
 ## Fail
 
 ```js
 import 'should'
 require('should')
+
+// In <PROJECT_ROOT>/src/app.js
+import '../styles/app.css'
+// {"allow": ["styles/*.css"]}
 ```
 
 
@@ -34,4 +47,13 @@ bar(require('foo'))
 require('foo').bar
 require('foo').bar()
 require('foo')()
+
+// With allow option set
+import './style.css' // {"allow": ["**/*.css"]}
+import 'babel-register' // {"allow": ["babel-register"]}
+
+// In <PROJECT_ROOT>/src/app.js
+import './styles/app.css'
+import '../scripts/register.js'
+// {"allow": ["src/styles/**", "**/scripts/*.js"]}
 ```

src/rules/no-unassigned-import.js

@@ -1,4 +1,6 @@
 import isStaticRequire from '../core/staticRequire'
+import path from 'path'
+import minimatch from 'minimatch'
 
 function report(context, node) {
   context.report({
@@ -7,15 +9,40 @@ function report(context, node) {
   })
 }
 
+function testIsAllow(globs, filename, source) {
+  if (!Array.isArray(globs)) {
+    return false // default doesn't allow any patterns
+  }
+
+  let filePath
+
+  if (source[0] !== '.' && source[0] !== '/') { // a node module
+    filePath = source
+  } else {
+    filePath = path.resolve(path.dirname(filename), source) // get source absolute path
+  }
+
+  return globs.find(glob => (
+    minimatch(filePath, glob) ||
+    minimatch(filePath, path.join(process.cwd(), glob))
+  )) !== undefined
+}
+
 function create(context) {
+  const options = context.options[0] || {}
+  const filename = context.getFilename()
+  const isAllow = source => testIsAllow(options.allow, filename, source)
+
   return {
     ImportDeclaration(node) {
-      if (node.specifiers.length === 0) {
+      if (node.specifiers.length === 0 && !isAllow(node.source.value)) {
         report(context, node)
       }
     },
     ExpressionStatement(node) {
-      if (node.expression.type === 'CallExpression' && isStaticRequire(node.expression)) {
+      if (node.expression.type === 'CallExpression' &&
+        isStaticRequire(node.expression) &&
+        !isAllow(node.expression.arguments[0].value)) {
         report(context, node.expression)
       }
     },
@@ -33,6 +60,12 @@ module.exports = {
           'devDependencies': { 'type': ['boolean', 'array'] },
           'optionalDependencies': { 'type': ['boolean', 'array'] },
           'peerDependencies': { 'type': ['boolean', 'array'] },
+          'allow': {
+            'type': 'array',
+            'items': {
+              'type': 'string',
+            },
+          },
         },
         'additionalProperties': false,
       },

tests/src/rules/no-unassigned-import.js

@@ -29,6 +29,52 @@ ruleTester.run('no-unassigned-import', rule, {
     test({ code: 'require("lodash").foo'}),
     test({ code: 'require("lodash").foo()'}),
     test({ code: 'require("lodash")()'}),
+    test({
+      code: 'import "app.css"',
+      options: [{ 'allow': ['**/*.css'] }],
+    }),
+    test({
+      code: 'import "app.css";',
+      options: [{ 'allow': ['*.css'] }],
+    }),
+    test({
+      code: 'import "./app.css"',
+      options: [{ 'allow': ['**/*.css'] }],
+    }),
+    test({
+      code: 'import "foo/bar"',
+      options: [{ 'allow': ['foo/**'] }],
+    }),
+    test({
+      code: 'import "foo/bar"',
+      options: [{ 'allow': ['foo/bar'] }],
+    }),
+    test({
+      code: 'import "../dir/app.css"',
+      options: [{ 'allow': ['**/*.css'] }],
+    }),
+    test({
+      code: 'import "../dir/app.js"',
+      options: [{ 'allow': ['**/dir/**'] }],
+    }),
+    test({
+      code: 'require("./app.css")',
+      options: [{ 'allow': ['**/*.css'] }],
+    }),
+    test({
+      code: 'import "babel-register"',
+      options: [{ 'allow': ['babel-register'] }],
+    }),
+    test({
+      code: 'import "./styles/app.css"',
+      options: [{ 'allow': ['src/styles/**'] }],
+      filename: path.join(process.cwd(), 'src/app.js'),
+    }),
+    test({
+      code: 'import "../scripts/register.js"',
+      options: [{ 'allow': ['src/styles/**', '**/scripts/*.js'] }],
+      filename: path.join(process.cwd(), 'src/app.js'),
+    }),
   ],
   invalid: [
     test({
@@ -39,5 +85,26 @@ ruleTester.run('no-unassigned-import', rule, {
       code: 'require("lodash")',
       errors: [error],
     }),
+    test({
+      code: 'import "./app.css"',
+      options: [{ 'allow': ['**/*.js'] }],
+      errors: [error],
+    }),
+    test({
+      code: 'import "./app.css"',
+      options: [{ 'allow': ['**/dir/**'] }],
+      errors: [error],
+    }),
+    test({
+      code: 'require("./app.css")',
+      options: [{ 'allow': ['**/*.js'] }],
+      errors: [error],
+    }),
+    test({
+      code: 'import "./styles/app.css"',
+      options: [{ 'allow': ['styles/*.css'] }],
+      filename: path.join(process.cwd(), 'src/app.js'),
+      errors: [error],
+    }),
   ],
 })