add getUser

src/App.tsx

@@ -9,7 +9,7 @@ import { Todo } from './types/types';
 const initialTodos: Todo[] = todosFromServer;
 
 function getNewTodoId(todos: Todo[]) {
-  const maxId = Math.max(...todos.map(todo => todo.id));
+  const maxId = Math.max(0, ...todos.map(todo => todo.id));
 
   return maxId + 1;
 }
@@ -77,9 +77,7 @@ export const App = () => {
             value={title}
             onChange={handleTitle}
           />
-          {hasTitleError && (
-            <span className="error">Please enter a title{title}</span>
-          )}
+          {hasTitleError && <span className="error">Please enter a title</span>}
         </div>
 
         <div className="field">

src/components/UserInfo/UserInfo.tsx

@@ -1,17 +1,13 @@
 import React from 'react';
-import { Todo, User } from '../../types/types';
-import usersFromServer from '../../api/users';
+import { Todo } from '../../types/types';
+import { getUser } from '../../utils/getUser';
 
 type Props = {
   todo: Todo;
 };
 
-function getUser(arrUsers: User[], userId: number): User | undefined {
-  return arrUsers.find(el => el.id === userId);
-}
-
 export const UserInfo: React.FC<Props> = ({ todo }) => {
-  const user = getUser(usersFromServer, todo.userId);
+  const user = getUser(todo.userId);
 
   if (!user) {
     return <span className="UserInfo">Unknown User</span>;

src/utils/getUser.ts

@@ -0,0 +1,6 @@
+import { User } from '../types/types';
+import usersFromServer from '../api/users';
+
+export function getUser(userId: number): User | undefined {
+  return usersFromServer.find(el => el.id === userId);
+}