Use environment var in external iteration json data

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[EDITED] example

Pieces involved: iteratinoData from data.json, Postman app request body, Postman app pre-request script, newman js script

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Is it possible to use an environment variable to the iteration data in a json file?

For example:
Scenario 1: create a storage object to be used in following scenario -> will return respective objects with an id to be used in next iteration/scenario
Scenario 2: create a template with a storageid -> use group from env variable in the pre-request script of “create template” request. the request body would be a variable {{newTemplate}} from iteration data

run collection that runs scenario 1, then scenario 2

EXAMPLE:

Postman Request Body:
{{newTemplate}}

Postman Pre-Request Script:

// check if any new templates are left to create 
let newTemplates = pm.variables.get('newTemplates');

// start of scenarios, so get new templates to create
if (!newTemplates) {
    newTemplates = pm.iterationData.get("templates_data");
}

// set templates storage pool id in environment variables, using variable previously set
let templateStoragePool = JSON.parse(pm.variables.get('storagePool'));
pm.environment.set('templateStorageId', templateStoragePool.id);

// get first template from data.json templates_data object
let currentTemplate = newTemplates.shift();

// expect this to be used in Request Body with `{{templateStoragePool}}`
pm.environment.set("newTemplate", JSON.stringify(currentTemplate)); 

pm.environment.set("newTemplates", JSON.stringify(newTemplates));

// handle repeating request with next newTemplate if it exists
... 
}

iterationData : data.json

[
  {
    "scenario": "create a template and then a user",
    "routes": [
      "Create a template",
      "Create a user"
    ],
    "templates_data": [
      {
        "name": "template A",
        "storage": [
          {
            "storageId": "{{templateStorageId}}",
          }
        ]
      },
      {
        "name": "template B"
        "storage": [
          {
            "storageId": "{{templateStorageId}}",
          }
        ]
      }
    ]
  }
]

currently my newTemplate object that goes into the request looks like this when I do console.log:

        {
        "name": "template A",
        "storage": [
          {
            "storageId": "{{templateStorageId}}",
          }
        ]
      }

but what I want would be:

        {
        "name": "template A",
        "storage": [
          {
            "storageId": "190340-293849-13894",
          }
        ]
      }

newman script

function testCollection() {
  newman.run({
    collection: <myCollection>),
    iterationData: data.json
  }, function (err) {
    if (err) { throw err; }
    console.log('collection run complete!');
  }); 
}

*this is a very oversimplified example i came up with, in reality my scenarios/routes are much more complex so being able to pass variables this way would be really useful

TIA!

1 Like
2

Yes this work , in any field that allows calling variables as {{variable name }}

Example: request body

3

My question is how would I achieve this within my external json iteration data.

When the iteration data is read in, it reads the value as the string "{{region1id}}" instead of as an object and doesn’t get replaced by the env variable for region1id

I was hoping it would apply the region1id environment variable to the value of 'group', in the pre-request script, so when it gets used in the request body, the value is set correctly, instead of in the first newUser example I mentioned above.

Right now I am replacing the value in my pre-request script to make it work, (user.group = pm.environment.get('regionid')), but wanted to know if there’s a way to avoid writing code for this, or what I’m missing if it’s a matter of me doing something incorrectly

4 
pm.environment.set("hi",1)

console.log(pm.variables.replaceIn("this is {{hi}}"))

you can use pm.variables.replaceIn for script section . Everywhere else it will be replaced automatically

This is because variables are not referred as {{name}} in script sections

5

I’m not sure this is the same use case. I’m going to edit my original post to make it more clear, if you would look at it again I would appreciate it

[EDIT]
done editing original post

6

where are you using console.log to print it ? you should chack console and see what was actually send . It should be resolved correctly

My prerequest:

pm.environment.set("hello","123")

pm.environment.set("hi",JSON.stringify({

    "mean": 1710.2180279856818,

    "count": {"mean":"{{hello}}"},

    '5MinuteRate': 34.74630977619571,

    '15MinuteRate': 11.646507524106095

}))

RequestBody

make sure to select raw>json

image
image987Ă—195 4.45 KB

console: (see whats actually send)

image
image990Ă—227 6.83 KB

7

I have a console.info in my pre-request script right before setting the newTemplate env var:

console.info(template to create: ${JSON.stringify(currentTemplate)})

doubled checked and my RequestBody is correctly set to raw>json
I’m running a script to call newman from terminal (see SS - this has the actual data i used so I truncated it a bit):
image

8

[EDIT]
Ok, now I see that the log statement wouldn’t print it correctly but the request theoretically should work correctly - I will experiment a bit and update

9

Ok, I printed console.log(request.data); under Tests and I see that the values are set properly!

Thank you!