Regarding swagger is not working in nodejs as per the swagger document.

Hi asaddev ,

Typically when we see raw HTML coming back, it's because express is treating that route as "text/plain" or similar. Look to see if req.type() is being called before your call to swaggerUi.serve. Or some other method that would change the "Content-Type" of the response.

You can confirm the Content-Type is bad, by using curl or similar..

curl -i http://localhost:3000/api-docs
#...
HTTP/1.1 200 OK
X-Powered-By: Express
Content-Type: text/html; charset=utf-8 <------ Good content-type
#...

Here is a minimal index.js that works...

const swaggerUi = require('swagger-ui-express')
const swaggerDocument = require('./swagger.json')
const express = require('express')

const app = express()
app.use(
    '/api-docs',
    swaggerUi.serve,
    swaggerUi.setup(swaggerDocument)
);

const server = app.listen(3000, () => {
    console.log(`Server running at ${server.address().port}`);
});