refactor: userController and add req user type

server/src/types/express.d.ts

@@ -0,0 +1,25 @@
+/* eslint-disable no-unused-vars */
+declare namespace Express {
+  export type SocialLogin = {
+    provider: string
+    id: string
+    displayName?: string
+  }
+
+  export type PendingUser = {
+    email: string
+    socialLogin: SocialLogin
+  }
+
+  export interface ExistingUser {
+    id: string
+    username: string
+    email: string
+  }
+
+  export interface NewUser {
+    newUser?: PendingUser
+  }
+
+  export type User = ExistingUser | NewUser
+}