feat: add cleanDoubleSlashes (#2)

README.md

@@ -79,6 +79,17 @@ Ensures url does not ends with a trailing slash
 withoutTrailingSlash('/foo/')
 ```
 
+### `cleanDoubleSlashes`
+
+Ensures url does not have double slash (except for protocol)
+
+```ts
+// Result: /foo/bar/
+cleanDoubleSlashes('//foo//bar//')
+// Result: http://example.com/analyze/http://localhost:3000/
+cleanDoubleSlashes('http://example.com/analyze//http://localhost:3000//')
+```
+
 ## License
 
 MIT. Made with 💖

src/index.ts

@@ -13,6 +13,10 @@ export function withTrailingSlash (input: string = '/'): string {
   return input.endsWith('/') ? input : (input + '/')
 }
 
+export function cleanDoubleSlashes (input: string = '/'): string {
+  return input.split('://').map(str => str.replace(/\/{2,}/g, '/')).join('://')
+}
+
 export function hasProtocol (inputStr: string): boolean {
   return /\w+:\//.test(inputStr)
 }

test/doubleSlash.test.ts

@@ -0,0 +1,17 @@
+// @ts-nocheck
+import { cleanDoubleSlashes } from '../src'
+
+describe('cleanDoubleSlashes', () => {
+  const tests = {
+    '//foo//bar//': '/foo/bar/',
+    'http://foo.com//': 'http://foo.com/',
+    'http://foo.com/bar//foo/': 'http://foo.com/bar/foo/',
+    'http://example.com/analyze//http://localhost:3000//': 'http://example.com/analyze/http://localhost:3000/'
+  }
+
+  for (const input in tests) {
+    test(input, () => {
+      expect(cleanDoubleSlashes(input)).toBe(tests[input])
+    })
+  }
+})

test/join.test.ts

@@ -7,6 +7,7 @@ describe('joinURL', () => {
     { input: ['a'], out: '/a' },
     { input: ['a', 'b'], out: '/a/b' },
     { input: ['a', 'b/', 'c'], out: '/a/b/c' },
+    { input: ['a', 'b/', '/c'], out: '/a/b/c' },
     { input: ['/a?foo=bar#123', 'b/', 'c/'], out: '/a/b/c/?foo=bar#123' },
     { input: ['http://foo.com', 'a'], out: 'http://foo.com/a' }
   ]