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Saturday, December 8, 2012

Picking the tool for Component Testing

As i discussed in the previous post we realized we need to test our component, not just unit test code and do functional testing. Biggest reason was that we where cluttering our functional tests with validation a that didn't belong at that level. Cluttering tests with logic that doesn't belong at that level was increasing our test maint costs, something we knew rom the past we had to avoid.

Since our application is based on REST services exposed by components with very well defined responsibility its very well suited for component testing.

The responsibility for our components was clearly defined. A component test is a black box test with the responsibility of validating the functionality and interfaces of the component. This definition was somewhat a battle as some how our testers seem (our project and others in our company) to insist that they want to validate stuff on the database. I don't like beeing unreasonable but this was one thing I felt I had to be unreasonable on, black box means get the f*** out of our database. I still feel a bit bad about overriding our test managers on this but I still feel strongly that it had to be done. So all tests go through public or administrative interfaces on our components. Reason for this is obviously that I wanted our tests to support refactoring and not break when we change code.

The upside on forbidding database access was that we had to make a few administrative interfaces that we could eventually use for building admin tools.

So now what tools should we use? We where using Fitnesse for our functional testing but Fitnesse biggest weakness is that it doesn't separate test flow from test data. With functional testing this isn't really a big issue as each test is basically a flow of its own. But with component testing and it by nature beeing more detailed we saw that we would get much more tests cases per flow. Another weakness is that Fitnesse doesn't go all that well together with large XML/json document validation.

We do our GUI testing with selenium Fitnesse combo and that we would continue doing. But for our REST service testing our first choice was SoapUI. We prototyped a bit and decided we could accomplish what we wanted with it so we started building our tests. This was the single biggest mistake we made with our continuous delivery process.

Back in the days when we just did functional tests for our deliveries in Fitnesse we had a nice process  of test driven development. Our developers activly worked on developing testcases and fixtures and the tests went green as the code hit done. I really like it when it's functional test driven developement and think this is the best form of tdd. This went totally down the drain when we started using SoapUI for our component tests.

Our developers refused to touch SoapUI and started handing over functionality to testers for testing after they had coded it. This resulted in total chaos as we got a lot of untested checkins. Backloaded testing works extremely bad with a continuous delivery process. Especially since we didn't use feature flags.

This put us in an interesting dilemma. Do we choose a test tool that testers feel comfortable working with or do we choose a tool that developers like? I personally am very unreligious when it comes to tools. If it does the job then I don't care so much. But I've always had the opinion that test tools are for testers and its up to them, devs need to suck it up and contribute. Testers always seem to like clicky tools so I wasn't suprised that they wanted to use SoapUi.

We where sitting with a broken test process and our devs and testers no longer working together. Fortunately our testers came to the same conclusion and realized this tool was a dead end for us. The biggest killer was how bad the tool was suited for teamwork and versioning, even enterprise edition. Each and every checkin caused problems and you basically need to checkin all your suites for each reference you change. Horrible.

So after wasting nearly 3-4 months, growing our test dept and killing our dev process on SoapUI we decided to switch to RESTassured. For some of our components this is a definite improvement and its definitely a improvement process wise as our developers are happy to get involved. But I do still see some posible issues on our horizon with this choice. Though the biggest change is for our testers and how we as an organization view the tester role and that will be the topic of my next post.

One very nice thing though, our continuous delivery process is maven based so the change of tooling didn't affect it. Each test is triggered with mvn verify and as long as the tool has a maven plugins don't really care what tool they use for their components.

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