From c591343531455deb088353e21d0b9abca5774b75 Mon Sep 17 00:00:00 2001
From: Jan Potoms <2109932+Janpot@users.noreply.github.com>
Date: Sat, 4 Jul 2020 17:48:44 +0200
Subject: [PATCH] Fix hash change

---
 packages/next/next-server/lib/router/router.ts | 10 ++++------
 test/integration/basepath/pages/hello.js       |  5 +++++
 test/integration/basepath/test/index.test.js   | 16 ++++++++++++++++
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/packages/next/next-server/lib/router/router.ts b/packages/next/next-server/lib/router/router.ts
index 293af31acec1d..601703a1f367e 100644
--- a/packages/next/next-server/lib/router/router.ts
+++ b/packages/next/next-server/lib/router/router.ts
@@ -223,9 +223,7 @@ export default class Router implements BaseRouter {
     // until after mount to prevent hydration mismatch
     this.asPath =
       // @ts-ignore this is temporarily global (attached to window)
-      isDynamicRoute(pathname) && __NEXT_DATA__.autoExport
-        ? pathname
-        : delBasePath(as)
+      isDynamicRoute(pathname) && __NEXT_DATA__.autoExport ? pathname : as
     this.basePath = basePath
     this.sub = subscription
     this.clc = null
@@ -408,11 +406,11 @@ export default class Router implements BaseRouter {
       // WARNING: `_h` is an internal option for handing Next.js client-side
       // hydration. Your app should _never_ use this property. It may change at
       // any time without notice.
-      if (!options._h && this.onlyAHashChange(as)) {
-        this.asPath = as
+      if (!options._h && this.onlyAHashChange(cleanedAs)) {
+        this.asPath = cleanedAs
         Router.events.emit('hashChangeStart', cleanedAs)
         this.changeState(method, url, as, options)
-        this.scrollToHash(as)
+        this.scrollToHash(cleanedAs)
         Router.events.emit('hashChangeComplete', cleanedAs)
         return resolve(true)
       }
diff --git a/test/integration/basepath/pages/hello.js b/test/integration/basepath/pages/hello.js
index 082343638caa5..ab471c1dad506 100644
--- a/test/integration/basepath/pages/hello.js
+++ b/test/integration/basepath/pages/hello.js
@@ -65,5 +65,10 @@ export default () => (
         <h1>Error route</h1>
       </a>
     </Link>
+    <Link href="/hello#some-hash">
+      <a id="hash-change">
+        <h1>Hash change</h1>
+      </a>
+    </Link>
   </>
 )
diff --git a/test/integration/basepath/test/index.test.js b/test/integration/basepath/test/index.test.js
index 85cb7911b137c..96082d24808d4 100644
--- a/test/integration/basepath/test/index.test.js
+++ b/test/integration/basepath/test/index.test.js
@@ -383,6 +383,22 @@ const runTests = (context, dev = false) => {
     }
   })
 
+  it('should use urls without basepath in router events for hash changes', async () => {
+    const browser = await webdriver(context.appPort, '/docs/hello')
+    try {
+      await browser.eval('window._clearEventLog()')
+      await browser.elementByCss('#hash-change').click()
+
+      const eventLog = await browser.eval('window._getEventLog()')
+      expect(eventLog).toEqual([
+        ['hashChangeStart', '/hello#some-hash'],
+        ['hashChangeComplete', '/hello#some-hash'],
+      ])
+    } finally {
+      await browser.close()
+    }
+  })
+
   it('should use urls without basepath in router events for cancelled routes', async () => {
     const browser = await webdriver(context.appPort, '/docs/hello')
     try {