fix(v2): navbar dropdown crash when item.to is undefined (#3662)

* Fix for undefined path with dropdown menu in Navbar

* Filter out 'href' links and check for undefined in utils

* Minot syntax fixes

* allow isSamePath to accept undefined values

Co-authored-by: slorber <lorber.sebastien@gmail.com>

packages/docusaurus-theme-classic/src/__tests__/utils.test.js

@@ -19,4 +19,14 @@ describe('isSamePath', () => {
   test('should be false for compared path with double trailing slash', () => {
     expect(isSamePath('/docs', '/docs//')).toBeFalsy();
   });
+
+  test('should be true for twice undefined/null', () => {
+    expect(isSamePath(undefined, undefined)).toBeTruthy();
+    expect(isSamePath(undefined, undefined)).toBeTruthy();
+  });
+
+  test('should be false when one undefined', () => {
+    expect(isSamePath('/docs', undefined)).toBeFalsy();
+    expect(isSamePath(undefined, '/docs')).toBeFalsy();
+  });
 });

packages/docusaurus-theme-classic/src/utils/index.ts

@@ -6,7 +6,12 @@
  */
 
 // Compare the 2 paths, ignoring trailing /
-export const isSamePath = (path1, path2) => {
-  const normalize = (str) => (str.endsWith('/') ? str : `${str}/`);
+export const isSamePath = (
+  path1: string | undefined,
+  path2: string | undefined,
+) => {
+  const normalize = (pathname: string | undefined) => {
+    return !pathname || pathname?.endsWith('/') ? pathname : `${pathname}/`;
+  };
   return normalize(path1) === normalize(path2);
 };