http post request from Angular to Express server causes 404 error - node.js

Question

I'm making a request to Azure function on local
url = 'http://localhost:7071/api/saveGraphDataFlow'
save(body) {
let headers = new HttpHeaders()
headers.append('Content-Type', 'application/json')
return this.httpClient.post(this.url, body, { headers: headers }).pipe(
map(res => {
return res
})
)
}
On my express server I'm adding cors to response
const createHandler = require("azure-function-express").createHandler;
const express = require("express");
const routers = require("./routes/routes");
const app = express();
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header(
"Access-Control-Allow-Headers",
"Origin, X-Requested-With, Content-Type, Accept"
);
res.header("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE,OPTIONS");
next();
});
app.use("/api/", routers);
// Binds the express app to an Azure Function handler
module.exports = createHandler(app);
But when I send request I get this error :
Access to XMLHttpRequest at 'http://localhost:7071/api/saveGraphDataFlow' from origin 'http://localhost:4200' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
the preflight request is not passing

Answer 1

You could try to remove the extra slash from
app.use("/api/", routers);
and so it becomes:
app.use("/api", routers);
Also, as a sidenote, I have not seen your API router, and so maybe there is an extra slash or missing slash in there. Another thing I have noticed is that you're importing an entire folder (?) for your routers so make sure that you are importing a file at once. (i have not seen that, so this might not be true)