How to execute postman collection using newman.js for entire data?

i am trying to execute postman collection using newman.js because i need to extract the response and save to a file, below is the script i am using for that

var fs = require('fs'),
    newman = require('newman'),
    results = [];

newman.run({
        reporters: 'cli',
        collection: '/Users/prasad/Documents/migration/export_uuid_emails.postman_collection.json',
        iterationData: '/Users/prasad/Documents/migration/test.csv',
        //data: '/Users/prasad/Documents/migration/test.csv', // this also doesn't work
        iterationCount: 1,
        //iterationCount: 2, // this is iterting the same data two times
        environment: '/Users/prasad/Documents/migration/stage.postman_environment.json'
}).on('request', function(err, args) {
        if(!err) {
                var rawBody = args.response.stream,
                 body = rawBody.toString();

                results.push(JSON.parse(body));
        }
}).on('done', function(err, summary) {
        fs.writeFileSync('migration-report.json', JSON.stringify(results, null, 4));
});

below is the contents of test.csv

userId
0e4aab3a-62cb-4e23-8f44-40b1f1c5f9eb
a1d3e402-a83f-4918-9b7c-333d281be35d

below is the environment file

{
    "id": "8e50b25f-df1a-4c15-abe9-1f8e4728da13",
    "name": "stage",
    "values": [
        {
            "key": "baseUrl",
            "value": "https://stage.api.auth.aws.pen.com",
            "enabled": true
        },
        {
            "key": "accountStatus",
            "value": "active",
            "enabled": true
        }
    ],
    "_postman_variable_scope": "environment",
    "_postman_exported_at": "2020-03-16T10:51:49.468Z",
    "_postman_exported_using": "Postman/7.20.0"
}

According to the script it should execute for two userId's but it is always executing for only first userId, i tried with iterationCount with 2 but it's executing same id two times.
i followed newman documentation and a this reference
Can any one please help me on this ?
Thanks,
Prasad

Solution

After trying in different ways then i figured that it's because of iterationCount: 1 when i changed that to iterationCount: 0 it started working.
Even if you don't provide iterationCount whenever you are providing iterationData then it is working.
Below is my understanding
No.of entries in test.csv file are 3 So it's choosing those many no.of entries which is equal to iterationCount if you don't specify any value then it's looping all entries which is 3 in this case.

i hope it will helpful for some other people