[Fix] import/extensions: ignore non-main modules

CHANGELOG.md

@@ -6,6 +6,9 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 
 ## [Unreleased]
 
+### Fixed
+- [`import/extensions`]: ignore non-main modules ([#1563], thanks [@saschanaz])
+
 ## [2.19.1] - 2019-12-08
 ### Fixed
 - [`no-extraneous-dependencies`]: ensure `node.source` exists
@@ -620,6 +623,7 @@ for info on changes for earlier releases.
 
 [`memo-parser`]: ./memo-parser/README.md
 
+[#1563]: https://github.com/benmosher/eslint-plugin-import/pull/1563
 [#1551]: https://github.com/benmosher/eslint-plugin-import/pull/1551
 [#1542]: https://github.com/benmosher/eslint-plugin-import/pull/1542
 [#1521]: https://github.com/benmosher/eslint-plugin-import/pull/1521

src/core/importType.js

@@ -34,7 +34,7 @@ function isExternalPath(path, name, settings) {
 }
 
 const externalModuleRegExp = /^\w/
-function isExternalModule(name, settings, path) {
+export function isExternalModule(name, settings, path) {
   return externalModuleRegExp.test(name) && isExternalPath(path, name, settings)
 }
 
@@ -44,7 +44,7 @@ export function isExternalModuleMain(name, settings, path) {
 }
 
 const scopedRegExp = /^@[^/]+\/?[^/]+/
-function isScoped(name) {
+export function isScoped(name) {
   return scopedRegExp.test(name)
 }
 

src/rules/extensions.js

@@ -1,7 +1,7 @@
 import path from 'path'
 
 import resolve from 'eslint-module-utils/resolve'
-import { isBuiltIn, isExternalModuleMain, isScopedMain } from '../core/importType'
+import { isBuiltIn, isExternalModule, isScoped } from '../core/importType'
 import docsUrl from '../docsUrl'
 
 const enumValues = { enum: [ 'always', 'ignorePackages', 'never' ] }
@@ -110,8 +110,8 @@ module.exports = {
       return props.pattern[extension] || props.defaultConfig
     }
 
-    function isUseOfExtensionRequired(extension, isPackageMain) {
-      return getModifier(extension) === 'always' && (!props.ignorePackages || !isPackageMain)
+    function isUseOfExtensionRequired(extension, isPackage) {
+      return getModifier(extension) === 'always' && (!props.ignorePackages || !isPackage)
     }
 
     function isUseOfExtensionForbidden(extension) {
@@ -144,11 +144,11 @@ module.exports = {
       const extension = path.extname(resolvedPath || importPath).substring(1)
 
       // determine if this is a module
-      const isPackageMain = isExternalModuleMain(importPath, context.settings)
-        || isScopedMain(importPath)
+      const isPackage = isExternalModule(importPath, context.settings)
+        || isScoped(importPath)
 
       if (!extension || !importPath.endsWith(`.${extension}`)) {
-        const extensionRequired = isUseOfExtensionRequired(extension, isPackageMain)
+        const extensionRequired = isUseOfExtensionRequired(extension, isPackage)
         const extensionForbidden = isUseOfExtensionForbidden(extension)
         if (extensionRequired && !extensionForbidden) {
           context.report({

tests/src/rules/extensions.js

@@ -293,6 +293,7 @@ ruleTester.run('extensions', rule, {
         import bar from './bar.json'
         import Component from './Component'
         import baz from 'foo/baz'
+        import baw from '@scoped/baw/import'
         import express from 'express'
       `,
       options: [ 'always', {ignorePackages: true} ],
@@ -301,10 +302,6 @@ ruleTester.run('extensions', rule, {
           message: 'Missing file extension for "./Component"',
           line: 4,
           column: 31,
-        }, {
-          message: 'Missing file extension for "foo/baz"',
-          line: 5,
-          column: 25,
         },
       ],
     }),
@@ -315,6 +312,7 @@ ruleTester.run('extensions', rule, {
         import bar from './bar.json'
         import Component from './Component'
         import baz from 'foo/baz'
+        import baw from '@scoped/baw/import'
         import express from 'express'
       `,
       options: [ 'ignorePackages' ],
@@ -323,10 +321,6 @@ ruleTester.run('extensions', rule, {
           message: 'Missing file extension for "./Component"',
           line: 4,
           column: 31,
-        }, {
-          message: 'Missing file extension for "foo/baz"',
-          line: 5,
-          column: 25,
         },
       ],
     }),