gulp task with gulp-run-command doesn't work properly - command-line

Question

I'm trying to run json-server in a gulp task and I'm checking if the server runs, with the function portInUse.
Like this:
var gulputil = require('gulp-util')
var run = require('gulp-run-command').default
var gulp = require('gulp')
const args = [
'json-server --watch .\\src\\main\\app\\reactjs\\api\\db.json --port 3005'
]
var net = require('net');
var portInUse = function(port, callback) {
var server = net.createServer(function(socket) {
socket.write('Echo server\r\n');
socket.pipe(socket);
});
server.listen(port, '127.0.0.1');
server.on('error', function (e) {
callback(true);
});
server.on('listening', function (e) {
server.close();
callback(false);
});
};
gulp.task("initLocalJsonServer", function() {
portInUse(3005, function(returnValue) {
gulputil.log('1 ' + returnValue);
});
run(args);
portInUse(3005, function(returnValue) {
gulputil.log('2 ' + returnValue);
});
});
That command that is the value of args here, works as intended when I run it in command line, so there's nothing wrong with the command or json-server itself. If I run it, I get to see the json-server at localhost:3005
Now the output from the portInUse function indicates that the server starts, as the output is:
[10:33:56] 1 false
[10:33:56] 2 true
But if I go to localhost:3005 after the gulp tasks are done, I can't see any server running. What might be the reason?