Sonar Gerrit Plugin Release

Initial release

I am happy to announce a first release of my Sonar Gerrit plugin. This plugin reports Sonar violations on your patchsets to your Gerrit server. Sonar analyses full project, but only files included in patchset are commented on Gerrit. Please forward to project page for installation instructions.

This plugin is intended to use with Gerrit Trigger plugin for Jenkins CI server. Together they provide a great tool for automatic static code analysis.

How does it work?

At the moment you push a patchset to Gerrit, Jenkins is notified with a ssh event. It fetches a code with a patchset and it builds your changes. It quits when build or tests fail.

But if it succeeds, Sonar analase your project in a post-build action. This is a place where my Sonar Gerrit plugin shines. It asks Gerrit for changed files before analysis and after Sonar analysis is finished, plugin reports comments on these files as a Gerrit reviewer. Currently plugin always reports +1 for Code Review, as it's still in development. However, you should always treat these comments as hints to improve, not as direct errors.

Extras

I've released also a second plugin: Sonar File Alerts plugin. This plugin raises alerts on file level in Sonar. It extends default behaviour, which raises alerts only at root project level. It is useful when you create alert rules in Sonar like "Code Coverage < 60". Each file is checked against this rule!

If you use Sonar File Alerts plugin and an alert will be generated on some file, then a comment will be published on this file on Gerrit.

Feedback

Please provide a feedback on these plugins. Feel free to submit issues on github or comment. It's still an early stage so your input is very welcome!

Sonar Gerrit Plugin Release

Initial release

I am happy to announce a first release of my Sonar Gerrit plugin. This plugin reports Sonar violations on your patchsets to your Gerrit server. Sonar analyses full project, but only files included in patchset are commented on Gerrit. Please forward to project page for installation instructions.

This plugin is intended to use with Gerrit Trigger plugin for Jenkins CI server. Together they provide a great tool for automatic static code analysis.

How does it work?

At the moment you push a patchset to Gerrit, Jenkins is notified with a ssh event. It fetches a code with a patchset and it builds your changes. It quits when build or tests fail.

But if it succeeds, Sonar analase your project in a post-build action. This is a place where my Sonar Gerrit plugin shines. It asks Gerrit for changed files before analysis and after Sonar analysis is finished, plugin reports comments on these files as a Gerrit reviewer. Currently plugin always reports +1 for Code Review, as it's still in development. However, you should always treat these comments as hints to improve, not as direct errors.

Extras

I've released also a second plugin: Sonar File Alerts plugin. This plugin raises alerts on file level in Sonar. It extends default behaviour, which raises alerts only at root project level. It is useful when you create alert rules in Sonar like "Code Coverage < 60". Each file is checked against this rule!

If you use Sonar File Alerts plugin and an alert will be generated on some file, then a comment will be published on this file on Gerrit.

Feedback

Please provide a feedback on these plugins. Feel free to submit issues on github or comment. It's still an early stage so your input is very welcome!

How to use mocks in controller tests

Even since I started to write tests for my Grails application I couldn't find many articles on using mocks. Everyone is talking about tests and TDD but if you search for it there isn't many articles.

Today I want to share with you a test with mocks for a simple and complete scenario. I have a simple application that can fetch Twitter tweets and present it to user. I use REST service and I use GET to fetch tweets by id like this: http://api.twitter.com/1/statuses/show/236024636775735296.json. You can copy and paste it into your browser to see a result.

My application uses Grails 2.1 with spock-0.6 for tests. I have TwitterReaderService that fetches tweets by id, then I parse a response into my Tweet class.

TwitterController plays main part here. Users call show action along with id of a tweet. This action is my subject under test. I've implemented some basic functionality. It's easier to focus on it while writing tests.

Let's start writing a test from scratch. Most important thing here is that I use mock for my TwitterReaderService. I do not construct new TwitterReaderService(), because in this test I test only TwitterController. I am not interested in injected service. I know how this service is supposed to work and I am not interested in internals. So before every test I inject a twitterReaderServiceMock into controller:

Now it's time to think what scenarios I need to test. This line from TwitterReaderService is the most important:

You must think of this method like a black box right now. You know nothing of internals from controller's point of view. You're only interested what can be returned for you:

  • a TwitterError can be thrown
  • null can be returned
  • Tweet instance can be returned

This list is your test blueprint. Now answer a simple question for each element: "What do I want my controller to do in this situation?" and you have plan test:

  • show action should redirect to index if TwitterError is thrown and inform about error
  • show action should redirect to index and inform if tweet is not found
  • show action should show found tweet

That was easy and straightforward! And now is the best part: we use twitterReaderServiceMock to mock each of these three scenarios!

In Spock there is a good documentation about interaction with mocks. You declare what methods are called, how many times, what parameters are given and what should be returned. Remember a black box? Mock is your black box with detailed instruction, e.g.: I expect you that if receive exactly one call to readTweet with parameter '1' then you should throw me a TwitterError. Rephrase this sentence out loud and look at this:

This is a valid interaction definition on mock! It's that easy! Here is a complete test that fails for now:

You may notice 0 * _._ notation. It says: I don't want any other mocks or any other methods called. Fail this test if something is called! It's a good practice to ensure that there are no more interactions than you want.

Ok, now I need to implement controller logic to handle TwitterError.

My tests passes! We have two scenarios left. Rule stays the same: TwitterReaderService returns something and we test against it. So this line is the heart of each test, change only returned values after >>:

Here is a complete test for three scenarios and controller that passes it.

The most important thing here is that we've tested controller-service interaction without logic implementation in service! That's why mock technique is so useful. It decouples your dependencies and let you focus on exactly one subject under test. Happy testing!