[Fix] importType: fix isExternalModule calculation

Fixes #2258

Author: mx-bernhard

CHANGELOG.md

@@ -8,6 +8,7 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 
 ### Fixed
 - [`extensions`]: ignore unresolveable type-only imports ([#2270], [#2271], [@jablko])
+- `importType`: fix `isExternalModule` calculation ([#2282], [@mx-bernhard])
 
 ### Changed
 - [Docs] [`order`]: add type to the default groups ([#2272], [@charpeni])
@@ -937,6 +938,8 @@ for info on changes for earlier releases.
 
 [`memo-parser`]: ./memo-parser/README.md
 
+[#2282]: https://github.com/import-js/eslint-plugin-import/pull/2282
+[#2279]: https://github.com/import-js/eslint-plugin-import/pull/2279
 [#2272]: https://github.com/import-js/eslint-plugin-import/pull/2272
 [#2271]: https://github.com/import-js/eslint-plugin-import/pull/2271
 [#2270]: https://github.com/import-js/eslint-plugin-import/pull/2270
@@ -1543,6 +1546,7 @@ for info on changes for earlier releases.
 [@MikeyBeLike]: https://github.com/MikeyBeLike
 [@mplewis]: https://github.com/mplewis
 [@mrmckeb]: https://github.com/mrmckeb
+[@mx-bernhard]: https://github.com/mx-bernhard
 [@nickofthyme]: https://github.com/nickofthyme
 [@nicolashenry]: https://github.com/nicolashenry
 [@noelebrun]: https://github.com/noelebrun

src/core/importType.js

@@ -29,7 +29,7 @@ export function isExternalModule(name, settings, path, context) {
   if (arguments.length < 4) {
     throw new TypeError('isExternalModule: name, settings, path, and context are all required');
   }
-  return isModule(name) && isExternalPath(name, settings, path, getContextPackagePath(context));
+  return (isModule(name) || isScoped(name)) && isExternalPath(name, settings, path, getContextPackagePath(context));
 }
 
 export function isExternalModuleMain(name, settings, path, context) {

tests/src/core/importType.js

@@ -234,11 +234,21 @@ describe('importType(name)', function () {
   it('`isExternalModule` works with windows directory separator', function () {
     const context = testContext();
     expect(isExternalModule('foo', {}, 'E:\\path\\to\\node_modules\\foo', context)).to.equal(true);
+    expect(isExternalModule('@foo/bar', {}, 'E:\\path\\to\\node_modules\\@foo\\bar', context)).to.equal(true);
     expect(isExternalModule('foo', {
       'import/external-module-folders': ['E:\\path\\to\\node_modules'],
     }, 'E:\\path\\to\\node_modules\\foo', context)).to.equal(true);
   });
 
+  it('`isExternalModule` works with unix directory separator', function () {
+    const context = testContext();
+    expect(isExternalModule('foo', {}, '/path/to/node_modules/foo', context)).to.equal(true);
+    expect(isExternalModule('@foo/bar', {}, '/path/to/node_modules/@foo/bar', context)).to.equal(true);
+    expect(isExternalModule('foo', {
+      'import/external-module-folders': ['/path/to/node_modules'],
+    }, '/path/to/node_modules/foo', context)).to.equal(true);
+  });
+
   it('correctly identifies scoped modules with `isScoped`', () => {
     expect(isScoped('@/abc')).to.equal(false);
     expect(isScoped('@/abc/def')).to.equal(false);