Nodejs Express api cors error on calling api using angular frontend

I created api using nodejs express mongodb and its giving cors error when i call api from angular application. I deployed this api on render then its working but gives an error on local.

Error

Access to XMLHttpRequest at 'localhost:3000/api/auth/login' from origin 'http://localhost:4200' has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, isolated-app, brave, https, chrome-untrusted, data, chrome-extension, chrome. auth.service.ts:38 POST localhost:3000/api/auth/login net::ERR_FAILED schedu
​

I have installed cors and added app.use(cors({origin : "*"}))

or

app.use(cors({origin : "http://localhost:4200/"}))

But it still giving error.

Also, I tried adding this

app.use((req, res, next) => {
res.setHeader("Access-Control-Allow-Origin", "*");
res.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT");
res.setHeader("Access-Control-Allow-Headers", "Content-Type");
next();
}


still cors error.

here is my index.js

const express = require("express");
const app = express();
const dotEnv = require("dotenv");
const mongoose = require("mongoose");
const cors = require("cors");

app.use(cors({origin: "*"}));

app.use((req, res, next) => {
res.setHeader("Access-Control-Allow-Origin", "*");
res.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT");
res.setHeader("Access-Control-Allow-Headers", "Content-Type");
next();
}


dotEnv.config();

mongoose.set("strictQuery", false);
app.use(express.json());

mongoose.connect(process.env.DB_URL).then(function(){
console.log("connected");

});




applications = require("./routes/applications"),
auth = require("./routes/auth"),






app.use("/api/aplications", applications);
app.use("/api/auth/", auth);





const PORT = process.env.PORT || 3000;

app.listen(PORT, function(){
console.log(Date.now())
console.log("server started on port", PORT);
})

Continue reading...