[Fix] no-duplicates: avoid crash with empty import type {}

Fixes #2201

Author: ljharb

CHANGELOG.md

@@ -12,6 +12,7 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 - `ExportMap`: Add default export when esModuleInterop is true and anything is exported ([#2184], thanks [@Maxim-Mazurok])
 - [`named`], [`namespace`]: properly set reexports on `export * as … from` ([#1998], [#2161], thanks [@ljharb])
 - [`no-duplicates`]: correctly handle case of mixed default/named type imports ([#2149], thanks [@GoodForOneFare], [@nwalters512])
+- [`no-duplicates`]: avoid crash with empty `import type {}` ([#2201], thanks [@ljharb])
 
 ### Changed
 - [Docs] `max-dependencies`: 📖 Document `ignoreTypeImports` option ([#2196], thanks [@himynameisdave])
@@ -1150,6 +1151,7 @@ for info on changes for earlier releases.
 [#211]: https://github.com/import-js/eslint-plugin-import/pull/211
 [#164]: https://github.com/import-js/eslint-plugin-import/pull/164
 [#157]: https://github.com/import-js/eslint-plugin-import/pull/157
+[#2201]: https://github.com/import-js/eslint-plugin-import/issues/2201
 [#2161]: https://github.com/import-js/eslint-plugin-import/issues/2161
 [#2118]: https://github.com/import-js/eslint-plugin-import/issues/2118
 [#2067]: https://github.com/import-js/eslint-plugin-import/issues/2067

src/rules/no-duplicates.js

@@ -281,7 +281,7 @@ module.exports = {
 
     function getImportMap(n) {
       if (n.importKind === 'type') {
-        return n.specifiers[0].type === 'ImportDefaultSpecifier' ? defaultTypesImported : namedTypesImported;
+        return n.specifiers.length > 0 && n.specifiers[0].type === 'ImportDefaultSpecifier' ? defaultTypesImported : namedTypesImported;
       }
 
       return hasNamespace(n) ? nsImported : imported;

tests/src/rules/no-duplicates.js

@@ -446,6 +446,13 @@ context('TypeScript', function() {
             code: "import type x from './foo'; import type {y} from './foo'",
             ...parserConfig,
           }),
+          test({
+            code: `
+              import type {} from './module';
+              import {} from './module2';
+            `,
+            ...parserConfig,
+          }),
         ],
         invalid: [
           test({