I have checked other answers like this one Mocha API Testing: getting 'TypeError: app.address is not a function' and it seems the main issue for the error is not exporting the server but I think I am doing that.
Here is my test file spec.js
var request = require('supertest');
describe('loading express', function () {
var server;
beforeEach(function () {
delete require.cache[require.resolve('./index')];
server = require('./index');
});
afterEach(function (done) {
server.close(done);
});
it('responds to /', function testSlash(done) {
request(server)
.get('/')
.expect(200, done);
});
Here is my index.js file
import bodyParser from "body-parser";
import cookieParser from "cookie-parser";
import cors from "cors";
import express from "express";
import _ from "lodash";
import serveStatic from "serve-static";
const port = 8000;
export default (app) => {
app.use(express.json({ limit: "50mb" }));
app.use(
express.urlencoded({
extended: true
})
);
app.use(bodyParser.json({ limit: "50mb" }));
app.use(cors());
app.use(serveStatic("dist/", { index: ["index.html"] }));
app.use(cookieParser());
if (_.isNil(process.env.APP_ENV)) {
process.env.APP_ENV = "LOCAL";
}
// ... A load of variables and functions in here
// simple function to test
app.get('/', function (req, res) {
res.status(200).send('ok');
});
var server = app.listen(port, function () {
var port = server.address().port;
console.log('Example app listening at port %s', port);
});
module.exports = server;
};
index.js is exporting a function which takes app as an argument. So the import of index.js is a function which must be called with app.
spec.js
server = require('./index');
// replace with
server = require('./index')(app);
Assuming this remains as a function, and you call it with app in spec.js, as above, then you can get server by replacing module.exports = server; with return server;.
test.js
module.exports = server;
// replace with
return server;
Separately, there is also a mixture of ES Modules (import/export) and CommonJS Modules (module.exports/require) here which can result in a variety of weird behavior. If you can standardize on just one of these, it'll go a long way.
But if you continue to use require('./index') to import index.js which is an ES Module, you may need to try require('./index').default instead, to grab that default export.