fix: Unicode problem about atob/btoa (#85)

https://github.com/yusukebe/hono/pull/84#pullrequestreview-870144435

Thank you @danielweck

src/middleware/basic-auth/basic-auth.test.ts

@@ -11,20 +11,32 @@ describe('Basic Auth by Middleware', () => {
   })
 
   const app = new Hono()
+
   const username = 'hono-user-a'
   const password = 'hono-password-a'
+  const unicodePassword = '炎'
 
   app.use(
-    '*',
+    '/auth/*',
     basicAuth({
       username,
       password,
     })
   )
-  app.get('/', () => new Response('root'))
+
+  app.use(
+    '/auth-unicode/*',
+    basicAuth({
+      username: username,
+      password: unicodePassword,
+    })
+  )
+
+  app.get('/auth/*', () => new Response('auth'))
+  app.get('/auth-unicode/*', () => new Response('auth'))
 
   it('Unauthorized', async () => {
-    const req = new Request('http://localhost/')
+    const req = new Request('http://localhost/auth/a')
     const res = await app.dispatch(req)
     expect(res).not.toBeNull()
     expect(res.status).toBe(401)
@@ -34,11 +46,22 @@ describe('Basic Auth by Middleware', () => {
   it('Authorizated', async () => {
     const credential = Buffer.from(username + ':' + password).toString('base64')
 
-    const req = new Request('http://localhost/')
+    const req = new Request('http://localhost/auth/a')
+    req.headers.set('Authorization', `Basic ${credential}`)
+    const res = await app.dispatch(req)
+    expect(res).not.toBeNull()
+    expect(res.status).toBe(200)
+    expect(await res.text()).toBe('auth')
+  })
+
+  it('Authorizated Unicode', async () => {
+    const credential = Buffer.from(username + ':' + unicodePassword).toString('base64')
+
+    const req = new Request('http://localhost/auth-unicode/a')
     req.headers.set('Authorization', `Basic ${credential}`)
     const res = await app.dispatch(req)
     expect(res).not.toBeNull()
     expect(res.status).toBe(200)
-    expect(await res.text()).toBe('root')
+    expect(await res.text()).toBe('auth')
   })
 })

src/middleware/basic-auth/basic-auth.ts

@@ -32,8 +32,15 @@ const auth = (req: Request) => {
 }
 
 function decodeBase64(str: string) {
-  if (atob && btoa) {
-    return atob(str)
+  if (atob) {
+    const text = atob(str)
+    const length = text.length
+    const bytes = new Uint8Array(length)
+    for (let i = 0; i < length; i++) {
+      bytes[i] = text.charCodeAt(i)
+    }
+    const decoder = new TextDecoder()
+    return decoder.decode(bytes)
   } else {
     const { Buffer } = require('buffer')
     return Buffer.from(str, 'base64').toString()