Auto-generate Spock specs for Grails artifacts

When creating artifacts such as domain classes, controllers and tag libs Grails generates a JUnit test case. If, like me, you're digging writing specifications with Spock you'd probably rather have Grails generate one of those. The last thing I want is to manually transform every generated test case into a specification for every artifact I create.

It's very simple to create a CreateUnitSpec or CreateIntegrationSpec script with a template specification. Hooking in to the other types of artifact creation turned out to be fiddlier. Each create-* command calls a Closure called createUnitTest. Reassigning that Closure should be the solution. The trick is in figuring out where that can be done.

Any time one of its Gant targets is invoked the Grails build system fires an event. You can respond to those events by declaring a closure called event<target name>Start in scripts/_Events.groovy. The only Gant target directly invoked when an artifact is created is called 'default'. It is possible to intercept that although that means the event handler will be invoked any time any Gant target called 'default' runs. For this purpose that's no problem since we're just overriding a closure in the build binding.

The other factor is that the superclass for the unit test is specified by the individual create-* scripts (or defaulted to GrailsUnitTestCase). Rather than having to override those scripts as well, I've just mapped the non-standard unit test superclasses to the Spock equivalents.

Here's the code for your _Events.groovy script:
The template specification should be placed in src/templates/artifacts/Spec.groovy and is simply:
It goes without saying that this is a slightly hairy and it would be great if Grails provided a proper hook for overriding the test generation. I can live with some fun-size evil in _Events.groovy for the sake of the convenience of getting template specs for all my artifacts, though.

Scripting Plugin and Dependency Installation

Another quick script that I find quite useful, particularly on continuous integration servers is my Prepare.groovy script. It solves a couple of problems

• Some plugins are not as well behaved as others on installation, for example the Functional Testing plugin automatically installs when test-app or run-app is installed but will then immediately crash with a ClassNotFoundException because the libraries it depends on are not on the classpath yet. Re-running the command will then work but if the commands are part of a CI build it's probably already bombed out and reported a broken build.
• The Ivy plugin is great but test-app and run-app won't invoke its get-dependencies target to pull down libraries the way they will automatically install plugins.
• Sometimes the grails command you want the build to execute is supplied by a plugin so there's no convenient way to run it directly from a brand new workspace because the plugin isn't installed yet.

The script simply ensures all plugins are installed and then invokes the Ivy plugin's get-dependencies target (only if the Ivy plugin is installed - it won't blow up on you if you don't use Ivy). At that point you should have a fully workable workspace and be able to run any grails command you like without your app complaining that some library or other isn't present.

Checking for plugin updates

If you're anything like me you probably like to keep all your Grails plugins updated to the latest versions. It's quite easy to miss a release announcement and not realise there's a new version available. Although grails list-plugins will list out the available versions and what version you currently have installed it doesn't really highlight the plugins you could upgrade. I threw this script together this morning to do exactly that. It will simply check the plugin versions you have installed against all configured repositories and notify you of any that could be updated.