postman_scipts.js

// generating random data
var randomData = Math.random();

// getting Auth tokens from other Auth services
pm.sendRequest({
  url:"https://postman-echo.com/basic-auth",
  method: "GET",
  header: { 
    'Authorization': 'Basic ' + btoa('postman:password') 
  }
},
function (err, response) {
  pm.environment.set("token", res.json().authenticated);
});

// obtaining request body data from another service
pm.sendRequest("https://postman-echo.com/get", function (err, response) {
  var input = response.json();
  var jsonValue = input.headers.postman-token;
  pm.environment.set("reqBody", jsonValue);
});

// input validation
pm.test("Body matches string", function () {
  pm.expect("input_text").to.include("input");
});

//assign/change postman variables
var randomData = Math.random();
pm.environment.set("rand", randomData);


Test Script Snippets:
 
// output validation
var schema = {
  "items": {
    "type": "boolean"
   }
};
     
var data1 = [true, false];
var data2 = [true, 123];
        
pm.test('Schema is valid', function() {
  pm.expect(tv4.validate(data1, schema)).to.be.true;
  pm.expect(tv4.validate(data2, schema)).to.be.true;
});

// variable assignment
pm.environment.set("aThing", "thing1");

// convert data formats (xml to  json)
// get some xml

var responseBody = '<?xml version="1.0"?> \
        <catalog> \
           <book id="bk101"> \
              <author>Gambardella, Matthew</author> \
              <title>XML Developer\'s Guide</title> \
              <genre>Computer</genre> \
              <price>44.95</price> \
              <publish_date>2000-10-01</publish_date> \
              <description>An in-depth look at creating applications with XML.</description> \
           </book> \
           <book id="bk102"> \
              <author>Ralls, Kim</author> \
              <title>Midnight Rain</title> \
              <genre>Fantasy</genre> \
              <price>5.95</price> \
              <publish_date>2000-12-16</publish_date> \
              <description>A former architect battles corporate zombies, an evil sorceress, and her own childhood to become queen of the world.</description> \
           </book> \
        </catalog>'

var jsonObject = xml2Json(responseBody);

// sending requests (data persistence)
pm.sendRequest("https://postman-echo.com/get", function (err, response) {
  console.log(response.json());
});

// executing additional postman requests
pm.setNextRequest("POST Form Data");