[Fix] default: avoid crash with export =

Fixes #1818.

Co-authored-by: AndrewLeedham <AndrewLeedham@Outlook.com>
Co-authored-by: Jordan Harband <ljharb@gmail.com>

Author: AndrewLeedham

CHANGELOG.md

@@ -10,6 +10,7 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 
 ### Fixed
 - [`no-extraneous-dependencies`]/TypeScript: do not error when importing type from dev dependencies ([#1820], thanks [@fernandopasik])
+- [`default`]: avoid crash with `export =` ([#1822], thanks [@AndrewLeedham])
 
 ### Changed
 - [`no-extraneous-dependencies`]: add tests for importing types ([#1824], thanks [@taye])
@@ -711,6 +712,7 @@ for info on changes for earlier releases.
 [`memo-parser`]: ./memo-parser/README.md
 
 [#1824]: https://github.com/benmosher/eslint-plugin-import/pull/1824
+[#1822]: https://github.com/benmosher/eslint-plugin-import/pull/1822
 [#1820]: https://github.com/benmosher/eslint-plugin-import/pull/1820
 [#1819]: https://github.com/benmosher/eslint-plugin-import/pull/1819
 [#1802]: https://github.com/benmosher/eslint-plugin-import/pull/1802
@@ -1230,3 +1232,4 @@ for info on changes for earlier releases.
 [@nicolashenry]: https://github.com/nicolashenry
 [@fernandopasik]: https://github.com/fernandopasik
 [@taye]: https://github.com/taye
+[@AndrewLeedham]: https://github.com/AndrewLeedham

src/ExportMap.js

@@ -562,7 +562,9 @@ ExportMap.parse = function (path, content, context) {
 
     // This doesn't declare anything, but changes what's being exported.
     if (includes(exports, n.type)) {
-      const exportedName = n.expression && n.expression.name || n.id.name
+      const exportedName = n.type === 'TSNamespaceExportDeclaration'
+        ? n.id.name
+        : n.expression && n.expression.name || n.expression.id.name
       const declTypes = [
         'VariableDeclaration',
         'ClassDeclaration',

tests/files/typescript-export-assign-function.ts

@@ -0,0 +1 @@
+export = function foo() {};

tests/src/rules/default.js

@@ -174,6 +174,14 @@ context('TypeScript', function () {
               'import/resolver': { 'eslint-import-resolver-typescript': true },
             },
           }),
+          test({
+            code: `import foobar from "./typescript-export-assign-function"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+          }),
           test({
             code: `import foobar from "./typescript-export-assign-mixed"`,
             parser: parser,