Redirect URLs containing uppercase characters to lowercase (#266)

* Add tests for normalizeURL * Redirect requests containing uppercase in pathname to lowercase via normalizeURL * Fix typo

Author: jpreynat

src/lib/middleware.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect } from 'bun:test';
 
-import { getURLLookupAlternatives } from './middleware';
+import { getURLLookupAlternatives, normalizeURL } from './middleware';
 
 describe('getURLLookupAlternatives', () => {
  it('should return all URLs up to the root', () => {
@@ -104,3 +104,29 @@ describe('getURLLookupAlternatives', () => {
  ]);
  });
 });
+
+describe('normalizeURL', () => {
+ it('should remove trailing slashes', () => {
+ expect(normalizeURL(new URL('https://docs.mycompany.com/hello/'))).toEqual(
+ new URL('https://docs.mycompany.com/hello'),
+ );
+ });
+
+ it('should remove duplicate slashes', () => {
+ expect(normalizeURL(new URL('https://docs.mycompany.com//hello//there'))).toEqual(
+ new URL('https://docs.mycompany.com/hello/there'),
+ );
+ });
+
+ it('should convert uppercase characters in the path to lowercase', () => {
+ expect(normalizeURL(new URL('https://docs.mycompany.com/Hello/My/pAge'))).toEqual(
+ new URL('https://docs.mycompany.com/hello/my/page'),
+ );
+ });
+
+ it('should not affect uppercase characters in querystring parameters', () => {
+ expect(normalizeURL(new URL('https://docs.mycompany.com/Hello/My/pAge?Q=MySearch'))).toEqual(
+ new URL('https://docs.mycompany.com/hello/my/page?Q=MySearch'),
+ );
+ });
+})

src/lib/middleware.ts

@@ -90,9 +90,10 @@ export function getURLLookupAlternatives(input: URL) {
 
 /**
  * Normalize a URL to remove duplicate slashes and trailing slashes
+ * and transform the pathname to lowercase.
  */
 export function normalizeURL(url: URL) {
  const result = new URL(url);
- result.pathname = url.pathname.replace(/\/{2,}/g, '/').replace(/\/$/, '');
+ result.pathname = url.pathname.replace(/\/{2,}/g, '/').replace(/\/$/, '').toLowerCase();
  return result;
 }

src/middleware.ts

@@ -140,7 +140,7 @@ export async function middleware(request: NextRequest) {
  revision: resolved.revision,
  });
 
- // Because of how Next will encode, we need to encode ourselves the pathname before reriting to it.
+ // Because of how Next will encode, we need to encode ourselves the pathname before rewriting to it.
  const rewritePathname = normalizePathname(encodePathname(resolved.pathname));
 
  console.log(`${request.method} (${resolved.space}) ${rewritePathname}`);