Postman Pre-Request Script

script.js

// Adapted from:
// https://www.nicolaswidart.com/blog/automatically-set-authentication-tokens-in-postman-requests

var requiredAuthPath = pm.environment.get('requiredAuthPath');
var authServicePath = pm.environment.get('authServicePath');
var gatewayBaseUrl = pm.environment.get('gatewayBaseUrl');
var username = pm.environment.get('username');
var password = pm.environment.get('password');

var sdk = require('postman-collection');

var isValidTokenRequest = new sdk.Request({
    url: gatewayBaseUrl + requiredAuthPath, // Use an endpoint that requires being authenticated
    method: 'GET',
    header: [
        new sdk.Header({
            key: 'content-type',
            value: 'application/json',
        }),
        new sdk.Header({
            key: 'acccept',
            value: 'application/json',
        }),
        new sdk.Header({
            key: 'Authorization',
            value: 'Bearer ' + pm.globals.get("jwttoken"),
        }),
    ]
});

pm.sendRequest(isValidTokenRequest, function (err, response) {
    console.log(isValidTokenRequest);
    if (response.code === 401 || response.code === 403) {
        refreshToken();
    }
});

function refreshToken() {
    var tokenRequest = new sdk.Request({
    url: gatewayBaseUrl + authServicePath,
    method: 'POST',
    header: [
        new sdk.Header({
            key: 'content-type',
            value: 'application/json'
        }),
        new sdk.Header({
            key: 'acccept',
            value: 'application/json'
        }),
    ],
    body: {
        mode: 'raw',
        raw: JSON.stringify({
            username: username,
            password: password
        })
    }
  });

  pm.sendRequest(tokenRequest, function (err, response) {
      if (err) {
          throw err;
      }
      
      if (response.code !== 200) {
          throw new Error('Could not log in.');
      }
      // Response: http://www.postmanlabs.com/postman-collection/HeaderList.html
      pm.globals.set("jwttoken", response.headers.get("Authorization").split(' ')[1]);
  });
}