From f926178e63f617e8955a3ccd571b832e862a9a03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Lorber?= <slorber@users.noreply.github.com>
Date: Fri, 24 Jul 2020 12:40:24 +0200
Subject: [PATCH] fix(v2): baseUrl is wrongly appended to anchor links (#3112)

* fix baseurl being wrongly appended to anchor links

* fix baseurl being wrongly appended to anchor links
---
 .../docusaurus/src/client/exports/__tests__/useBaseUrl.ts | 4 ++++
 packages/docusaurus/src/client/exports/useBaseUrl.ts      | 8 ++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/packages/docusaurus/src/client/exports/__tests__/useBaseUrl.ts b/packages/docusaurus/src/client/exports/__tests__/useBaseUrl.ts
index eb5a7f1b6ed2..28a7def3b2b4 100644
--- a/packages/docusaurus/src/client/exports/__tests__/useBaseUrl.ts
+++ b/packages/docusaurus/src/client/exports/__tests__/useBaseUrl.ts
@@ -40,6 +40,7 @@ describe('useBaseUrl', () => {
     expect(useBaseUrl('/hello/byebye', {absolute: true})).toEqual(
       'https://v2.docusaurus.io/hello/byebye',
     );
+    expect(useBaseUrl('#hello')).toEqual('#hello');
   });
 
   test('non-empty base URL', () => {
@@ -69,6 +70,7 @@ describe('useBaseUrl', () => {
     );
     expect(useBaseUrl('/docusaurus/')).toEqual('/docusaurus/');
     expect(useBaseUrl('/docusaurus/hello')).toEqual('/docusaurus/hello');
+    expect(useBaseUrl('#hello')).toEqual('#hello');
   });
 });
 
@@ -99,6 +101,7 @@ describe('useBaseUrlUtils().withBaseUrl()', () => {
     expect(withBaseUrl('/hello/byebye', {absolute: true})).toEqual(
       'https://v2.docusaurus.io/hello/byebye',
     );
+    expect(withBaseUrl('#hello')).toEqual('#hello');
   });
 
   test('non-empty base URL', () => {
@@ -129,5 +132,6 @@ describe('useBaseUrlUtils().withBaseUrl()', () => {
     );
     expect(withBaseUrl('/docusaurus/')).toEqual('/docusaurus/');
     expect(withBaseUrl('/docusaurus/hello')).toEqual('/docusaurus/hello');
+    expect(withBaseUrl('#hello')).toEqual('#hello');
   });
 });
diff --git a/packages/docusaurus/src/client/exports/useBaseUrl.ts b/packages/docusaurus/src/client/exports/useBaseUrl.ts
index cd2f3123ca8f..627d140141a5 100644
--- a/packages/docusaurus/src/client/exports/useBaseUrl.ts
+++ b/packages/docusaurus/src/client/exports/useBaseUrl.ts
@@ -23,6 +23,11 @@ function addBaseUrl(
     return url;
   }
 
+  // it never makes sense to add a base url to a local anchor url
+  if (url.startsWith('#')) {
+    return url;
+  }
+
   // it never makes sense to add a base url to an url with a protocol
   if (hasProtocol(url)) {
     return url;
@@ -32,8 +37,7 @@ function addBaseUrl(
     return baseUrl + url;
   }
 
-  // sometimes we try to add baseurl to an url that already has a baseurl
-  // we should avoid adding the baseurl twice
+  // We should avoid adding the baseurl twice if it's already there
   const shouldAddBaseUrl = !url.startsWith(baseUrl);
 
   const basePath = shouldAddBaseUrl ? baseUrl + url.replace(/^\//, '') : url;