diff --git a/package.json b/package.json
index c607fd6..22debfd 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,9 @@
   "jest": {
     "preset": "ts-jest",
     "testEnvironment": "node",
-    "rootDir": "./src"
+    "rootDir": "./src",
+    "collectCoverage": true,
+    "coverageDirectory": "../coverage/"
   },
   "ts-standard": {
     "files": [
diff --git a/src/UnauthorizedError.ts b/src/UnauthorizedError.ts
new file mode 100644
index 0000000..fcf4028
--- /dev/null
+++ b/src/UnauthorizedError.ts
@@ -0,0 +1,16 @@
+export class UnauthorizedError extends Error {
+  public inner: { message: string }
+  public data: { message: string, code: string, type: 'UnauthorizedError' }
+
+  constructor (code: string, error: { message: string }) {
+    super(error.message)
+    this.message = error.message
+    this.inner = error
+    this.data = {
+      message: this.message,
+      code,
+      type: 'UnauthorizedError'
+    }
+    Object.setPrototypeOf(this, UnauthorizedError.prototype)
+  }
+}
diff --git a/src/__test__/authorize.test.ts b/src/__test__/authorize.test.ts
new file mode 100644
index 0000000..f77d8c8
--- /dev/null
+++ b/src/__test__/authorize.test.ts
@@ -0,0 +1,69 @@
+import axios from 'axios'
+import { io } from 'socket.io-client'
+
+import { fixtureStart, fixtureStop } from './fixture'
+
+describe('authorize', () => {
+  let token: string = ''
+
+  beforeEach((done) => {
+    jest.setTimeout(15_000)
+    fixtureStart(async () => {
+      const response = await axios.post('http://localhost:9000/login')
+      token = response.data.token
+      done()
+    })
+  })
+
+  afterEach((done) => {
+    fixtureStop(done)
+  })
+
+  it('should emit error with no token provided', (done) => {
+    const socket = io('http://localhost:9000')
+    socket.on('connect_error', (err: any) => {
+      expect(err.data.message).toEqual('no token provided')
+      expect(err.data.code).toEqual('credentials_required')
+      socket.close()
+      done()
+    })
+  })
+
+  it('should emit error with bad token format', (done) => {
+    const socket = io('http://localhost:9000', {
+      extraHeaders: { Authorization: 'testing' }
+    })
+    socket.on('connect_error', (err: any) => {
+      expect(err.data.message).toEqual(
+        'Format is Authorization: Bearer [token]'
+      )
+      expect(err.data.code).toEqual('credentials_bad_format')
+      socket.close()
+      done()
+    })
+  })
+
+  it('should emit error with unauthorized handshake', (done) => {
+    const socket = io('http://localhost:9000', {
+      extraHeaders: { Authorization: 'Bearer testing' }
+    })
+    socket.on('connect_error', (err: any) => {
+      expect(err.data.message).toEqual(
+        'Unauthorized: Token is missing or invalid Bearer'
+      )
+      expect(err.data.code).toEqual('invalid_token')
+      socket.close()
+      done()
+    })
+  })
+
+  it('should connect the user', (done) => {
+    const socket = io('http://localhost:9000', {
+      extraHeaders: { Authorization: `Bearer ${token}` }
+    })
+    socket.on('connect', () => {
+      socket.close()
+      done()
+    })
+  })
+})
diff --git a/src/__test__/fixture/index.ts b/src/__test__/fixture/index.ts
new file mode 100644
index 0000000..8bc99ad
--- /dev/null
+++ b/src/__test__/fixture/index.ts
@@ -0,0 +1,48 @@
+import express from 'express'
+import jwt from 'jsonwebtoken'
+import { Server as HttpServer } from 'http'
+import { Server as HttpsServer } from 'https'
+import { Server as SocketIoServer } from 'socket.io'
+import enableDestroy from 'server-destroy'
+
+import { authorize } from '../../index'
+
+interface Socket {
+  io: null | SocketIoServer
+  init: (httpServer: HttpServer | HttpsServer) => void
+}
+
+const socket: Socket = {
+  io: null,
+  init (httpServer) {
+    socket.io = new SocketIoServer(httpServer)
+  }
+}
+
+let server: HttpServer | null = null
+
+export const fixtureStart = (done: any): void => {
+  const options = { secret: 'aaafoo super sercret' }
+  const app = express()
+  app.use(express.json())
+  app.post('/login', (_req, res) => {
+    const profile = {
+      email: 'john@doe.com',
+      id: 123
+    }
+    const token = jwt.sign(profile, options.secret, { expiresIn: 60 * 60 * 5 })
+    return res.json({ token })
+  })
+  server = app.listen(9000, done)
+  socket.init(server)
+  socket.io?.use(authorize(options))
+  enableDestroy(server)
+}
+
+export const fixtureStop = (callback: Function): void => {
+  socket.io?.close()
+  try {
+    server?.destroy()
+  } catch (err) {}
+  callback()
+}
diff --git a/src/authorize.ts b/src/authorize.ts
new file mode 100644
index 0000000..810f6d7
--- /dev/null
+++ b/src/authorize.ts
@@ -0,0 +1,58 @@
+import jwt from 'jsonwebtoken'
+import { Socket } from 'socket.io'
+
+import { UnauthorizedError } from './UnauthorizedError'
+
+interface ExtendedError extends Error {
+  data?: any
+}
+
+type SocketIOMiddleware = (
+  socket: Socket,
+  next: (err?: ExtendedError) => void
+) => void
+
+interface AuthorizeOptions {
+  secret: string
+}
+
+export const authorize = (options: AuthorizeOptions): SocketIOMiddleware => {
+  const { secret } = options
+  return (socket, next) => {
+    let token: string | null = null
+    const authorizationHeader = socket.request.headers.authorization
+    if (authorizationHeader != null) {
+      const tokenSplitted = authorizationHeader.split(' ')
+      if (tokenSplitted.length !== 2 || tokenSplitted[0] !== 'Bearer') {
+        return next(
+          new UnauthorizedError('credentials_bad_format', {
+            message: 'Format is Authorization: Bearer [token]'
+          })
+        )
+      }
+      token = tokenSplitted[1]
+    }
+    if (token == null) {
+      return next(
+        new UnauthorizedError('credentials_required', {
+          message: 'no token provided'
+        })
+      )
+    }
+    // Store encoded JWT
+    socket = Object.assign(socket, { encodedToken: token })
+    let payload: any
+    try {
+      payload = jwt.verify(token, secret)
+    } catch {
+      return next(
+        new UnauthorizedError('invalid_token', {
+          message: 'Unauthorized: Token is missing or invalid Bearer'
+        })
+      )
+    }
+    // Store decoded JWT
+    socket = Object.assign(socket, { decodedToken: payload })
+    return next()
+  }
+}
diff --git a/src/index.ts b/src/index.ts
index 22eae88..66f83be 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,73 +1 @@
-import jwt from 'jsonwebtoken'
-import { Socket } from 'socket.io'
-
-class UnauthorizedError extends Error {
-  public inner: { message: string }
-  public data: { message: string, code: string, type: 'UnauthorizedError' }
-
-  constructor (code: string, error: { message: string }) {
-    super(error.message)
-    this.message = error.message
-    this.inner = error
-    this.data = {
-      message: this.message,
-      code,
-      type: 'UnauthorizedError'
-    }
-    Object.setPrototypeOf(this, UnauthorizedError.prototype)
-  }
-}
-
-interface ExtendedError extends Error {
-  data?: any
-}
-
-type SocketIOMiddleware = (
-  socket: Socket,
-  next: (err?: ExtendedError) => void
-) => void
-
-interface AuthorizeOptions {
-  secret: string
-}
-
-export const authorize = (options: AuthorizeOptions): SocketIOMiddleware => {
-  const { secret } = options
-  return (socket, next) => {
-    let token: string | null = null
-    const authorizationHeader = socket.request.headers.authorization
-    if (authorizationHeader != null) {
-      const tokenSplitted = authorizationHeader.split(' ')
-      if (tokenSplitted.length !== 2 || tokenSplitted[0] !== 'Bearer') {
-        return next(
-          new UnauthorizedError('credentials_bad_format', {
-            message: 'Format is Authorization: Bearer [token]'
-          })
-        )
-      }
-      token = tokenSplitted[1]
-    }
-    if (token == null) {
-      return next(
-        new UnauthorizedError('credentials_required', {
-          message: 'no token provided'
-        })
-      )
-    }
-    // Store encoded JWT
-    socket = Object.assign(socket, { encodedToken: token })
-    let payload: any
-    try {
-      payload = jwt.verify(token, secret)
-    } catch {
-      return next(
-        new UnauthorizedError('invalid_token', {
-          message: 'Unauthorized: Token is missing or invalid Bearer'
-        })
-      )
-    }
-    // Store decoded JWT
-    socket = Object.assign(socket, { decodedToken: payload })
-    return next()
-  }
-}
+export * from './authorize'