Run a Postman request multiple times using an array from a previous step

Question

I am working on some test scripts and data cleanup scripts using postman, and was wondering if it were possible to run a request on an array result produced in a previous step.

For example, I have an API that returns tasks as a JSON like so:

[
    {
        "active": true,
        "_id": "5b2101244651a04a4907b094",
        "name": "Test Task",
        "updatedAt": "2018-06-13T11:33:56.911Z",
        "createdAt": "2018-06-13T11:33:56.911Z"
    },
    {
        "active": true,
        "_id": "5b2101244651a04a4907b067",
        "name": "Test Task 2",
        "updatedAt": "2018-06-13T11:33:56.911Z",
        "createdAt": "2018-06-13T11:33:56.911Z"
    }
]

So in the Tests scripts I run this to collect an array of the IDs:

var jsonData = JSON.parse(responseBody)
postman.setEnvironmentVariable('task_id_list', jsonData.map((i) => i._id))

The next request is to delete a task, but the API only deletes one at a time. I am trying to do something like:

http://localhost:3000/api/v1/tasks/{{task_id_list}}

I was hoping that Postman would see that task_id_list was an array and simple "work", but that doesn't seem to be the case. Is it possible to have a step run multiple times based on an array input?

Could you add something in the pre-request script of the second request and maybe pop an item from the list? Each one would be a stored as a new variable, this would then be referenced in the URL for the delete request. Never tried doing this so i'm interested in the solution.. — Danny Dainton, Jun 14 '18 at 11:31

Borys Fursov · Accepted Answer · 2018-12-19T18:20:07.433

Solution from this article

Get array of ID's in test script of first request (I prefer to store it in JSON to avoid bugs):

let JsonData = pm.response.json();
let iDs = JsonData.map((i) => i._id)));
pm.environment.set("IdArray", JSON.stringify(iDs);
//and now check, if there was no objects returned, stop runner
if(iDs.length === 0)
{
    postman.setNextRequest(null);//next request will not be sent
}
else
{
    pm.environment.set("count", 0);
}

In pre-request script of 2 request:

var count = +pm.environment.get("count");
var iDs = JSON.parse(pm.environment.get("IdArray"));
pm.variables.set("task_id_list", iDs[count]); //like one-request environment variable
count = count + 1; //next iteration
if(count < iDs.length)
{
    postman.setNextRequest("NAME OF THIS REQUEST");
}
else 
{
    postman.setNextRequest(null); // or next request name
} 
pm.environment.set("count", count)

So you should understand my idea.

Did you forget to increase the count in the second script? – Jonny Dec 19 '18 at 08:11 — Jonny, Dec 19 '18 at 08:11

Run a Postman request multiple times using an array from a previous step

1 Answers1