How to pass variables from JSON to postman body

Question

I want to parameterized my tests in Postman. This is the example body of POST request:

{
  "entity_id": "{{entity_id}}",
  "text": data.comment_name
}

entity_id is global variable and it works correctly, but I want to set value of text from JSON file. data.comment_name doesn't work it saved me exactly data.comment_name as text variable. I want to include this JSON file with all variables in collection runner. How can I do that?

Retrusion

Have you tried this without adding the “data” part and using just {{comment_name}} – Thermion

that's work, thank you :) – Retrusion

Awesome! I've added an answer to the question. If it's correct and works for you, please close out this question. – Thermion

Answer 1

If your data file looks something like this JSON example:

[
    {
        "entity_id": 1,
        "comment_name": "This is my comment_name"
    }
]

To reference the values in the file, the POST body needs to look like this:

This is how your example would be but you don't need to add the " " around the variable. This could cause issues if the value is a number and adding the quotes around the value in the request body, would make this a string and possibly lead to a bad request.

Thermion

Answer 2

Pre-request Script ^{Add variable to JSON body}

By using pre-request scripts we can change the variable values, parameters, headers, and body data before a request runs by execting JavaScript.

Post URL : http://postman-echo.com/post ^{Code tested in Postman-win64-8.12.4-Setup}

Request Body - raw

{
    "locale": "en_US",
    "key"   : "{{dynamic_key}}",
    "value" : "{{dynamic_val}}"
}

Writing pre-request scripts

pm.collectionVariables.set("dynamic_key", "key1");
pm.collectionVariables.set("dynamic_val", "val1");

console.log('Add variable to JSON body', pm.request.body);

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• Sending parameters [Query parameters(?id=1&type=new), Path parameters (/customer/:id)]

Lording