node.js todo

server.js

const express=require('express')
const app=express()
 
let todo=[]
app.use(express.json())
app.use(express.urlencoded({extended: true}))

app.get('/todo',(req,res) =>
{
    if(todo.length==0)
    {
        res.send({error:'todo is empty'})
    }
    else
    {
    res.send(todo)
    }
})
app.get('/todo/:id',(req,res)=>
{
    const id=req.params.id
    res.send(todo[id])
})
app.post('/todo',(req,res)=>
{
    todo.push({
        task:req.body.task,
        priority:req.body.priority

    })
    res.send({success: true})
})

app.put('/todo/:id',(req,res)=>
{
    const id=req.param.id;
    let task=req.body.task, priority=req.body.priority;

    if(id>todo.length-1 ||(task=null && priority==null))
    {
     res.send({error:'no todo to replace'})
    }
    else{
        todo[id].task=task;
        todo[id].priority=priority;
        res.send('replaced successfully')

    }

})
app.delete('/todos/:id', (req, res) => {
    const id = req.params.id;
    if(id > todos.length - 1) {
      res.send({error: "Todo with given id does not exist."})
    } else {
      todos.splice(id, 1);
      res.send({msg: "Todo deleted successfully"});
    }

  })

  app.patch('/todos/:id', (req, res) => {
    const id = req.params.id;
    let task = req.body.task, priority = req.body.priority;
    if(id > todos.length - 1 || (task == null && priority == null)) {
      res.send({error: "No todo to update"})
    } else {
      if(task != null)
        todos[id].task = task;
      if(priority != null)
        todos[id].priority = parseInt(priority);
      res.send({msg: "Todo updated successfully."})
    }
  })

app.listen(9000)