fix: handle missing case for function overloads (#31)

src/prefer-arrow-functions.spec.ts

@@ -124,6 +124,10 @@ const alwaysValid = [
   {
     code: 'export function foo(val: string): void; export function foo(val: number): void; export function foo(val: string | number): void {}',
   },
+  // export { x }; has node.declaration === null - regression test for this case
+  {
+    code: 'export { foo }; export function bar(val: number): void; export function bar(val: string | number): void {}',
+  },
 ];
 
 const validWhenSingleReturnOnly = [
@@ -439,6 +443,13 @@ const invalidAndHasSingleReturn = [
     output:
       'var withLoop = async () => async () => { for (i = 0; i < 5; i++) {}}',
   },
+
+  // function overloading - don't mislabel as overload
+  //   export { x }; has node.declaration === null - regression test for this case
+  {
+    code: 'export { foo }; export async function bar() { return false; }',
+    output: 'export { foo }; export const bar = async () => false;',
+  },
 ];
 
 const invalidAndHasSingleReturnWithMultipleMatches = [

src/prefer-arrow-functions.ts

@@ -9,7 +9,7 @@ import {
 export default {
   meta: {
     docs: {
-      category: 'emcascript6',
+      category: 'ecmascript6',
       description: 'prefer arrow functions',
       recommended: false,
     },
@@ -110,7 +110,7 @@ export default {
       if (previousNode.type === 'TSDeclareFunction') return true;
       if (
         previousNode.type === 'ExportNamedDeclaration' &&
-        previousNode.declaration.type === 'TSDeclareFunction'
+        previousNode.declaration?.type === 'TSDeclareFunction'
       )
         return true;