Sunday, June 10, 2018

Postman Masterclass Pt. 2

During my second Postman meetup as part of the Las Vegas Test Automation group, we were able to cover some of the more advanced features of Postman. It's a valuable tool for testing RESTful services (stronger opinions on that also exist), and they are piling on features so fast that it is hard to keep track. If you're a business trying to add automation, Postman is easily the lowest barrier to entry to doing so. And with a few tweaks (or another year of updates) it could probably solve most of your API testing.

The meetup covered the Documentation, Mock Server and Monitor functionality. These are pieces that can fit in your dev organization to smoothe adoption, unroadblock, and add automation with very little overhead. Particularly, the Mock servers they offer can break the dependency on third party integrations quite handily. This keeps Agile sprints moving in the face of outside roadblocks. The Monitors seem like a half-measure. They gave a GUI for setting up external monitors of your APIs, but you still need Jenkins and their Newman node package to do it within your dev env. The big caveat with each of these is that they are most powerful when bought in conjunction with the Postman Enterprise license.  Still, at $20 a head, it's far and away the least expensive offering on the market.

Since the meetup, I've found a few workarounds for the features I wish it had that aren't immediately accessible from the GUI. As we know in testing in general, there is no one-size fits all solution.  And the new features are nice, but they don't offer some of the basics I rely on to make my job easier.  Here is my ever-expanding list of add-ons and hidden things you might not know about.  Feel free to comment or message me with more:

Postman has data generation in requests through Dynamic Variables, but they're severely limited in functionality. Luckily, someone dockerized npm faker into a restful service. This is super easy to slip stream into your Postman Collections to create rich and real-enough test data. Just stand it up, query, save the results to global variables, and reuse them in your tests.

The integrated JavaScript libraries in the Postman Sandbox are worth a fresh look. The bulk of my work uses lodash, crypto libraries, and tools for validating and parsing JSON. This turns your simple requests to data validation and schema tracking wonders. 

  • Have a Swagger definition you don't trust? Throw it in the tv4 schema validator. 
  • Have a deep tree of objects you need to be able to navigate RESTfully? Slice and dice with lodash, pick objects at random, and throw it up into a monitor. Running it every ten minutes should get you down onto the nooks and crannies.
This article on bringing the big list of naughty strings (https://ambertests.com/2018/05/29/testing-with-naughty-strings-in-postman/amp/) is another fantastic way to fold in interesting data to otherwise static tests. The key is to ensure you investigate failures. To get the most value, you need good logs, and you need to pay attention to your results in your Monitors.

If you have even moderate coding skills among your testers, they can work magic on a Postman budget. If you were used to adding your own libraries in the Chrome App, beware: the move to a packaged app means you no longer have the flexibility to add that needed library on your own (faker, please?).

More to come as I hear of them.
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