51.5.2. Writing tests for your plugin
You can use the ProjectBuilder class to create Project instances to use when you test your
plugin implementation.
Example 51.8. Testing a custom plugin
src/test/groovy/org/gradle/GreetingPluginTest.groovy
class GreetingPluginTest { @Test
public void greeterPluginAddsGreetingTaskToProject() { Project project = ProjectBuilder.builder().build() project.apply plugin: 'greeting'
assertTrue(project.tasks.hello instanceof GreetingTask)
}
}
51.6. Maintaining multiple domain objects
Gradle provides some utility classes for maintaining collections of object, which work well with the Gradle build language.
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Example 51.9. Managing domain objects
build.gradle
apply plugin: DocumentationPlugin
books { quickStart {
sourceFile = file('src/docs/quick-start')
}
userGuide {
}
developerGuide {
}
}
task books << { books.each { book ->
println "$book.name -> $book.sourceFile"
}
}
class DocumentationPlugin implements Plugin<Project> { void apply(Project project) {
def books = project.container(Book) books.all {
sourceFile = project.file("src/docs/$name")
}
project.extensions.books = books
}
}
class Book {
final String name File sourceFile
Book(String name) { this.name = name
}
}
Output of gradle -q books
> gradle -q books
developerGuide -> /home/user/gradle/samples/userguide/organizeBuildLogic/custo quickStart -> /home/user/gradle/samples/userguide/organizeBuildLogic/customPlu userGuide -> /home/user/gradle/samples/userguide/organizeBuildLogic/customPlug
The Project.container() methods create instances of NamedDomainObjectContainer, that have many useful methods for managing and configuring the objects. In order to use a type with any of the project.container methods, it MUST expose a property named “name” as the unique, and constant, name for the object. The project.container(Class) variant of the
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container method creates new instances by attempting to invoke the constructor of the class that takes a single string argument, which is the desired name of the object. See the above link for proj method variants that allow custom instantiation strategies.
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52
Organizing Build Logic
Gradle offers a variety of ways to organize your build logic. First of all you can put your build logic directly in the action closure of a task. If a couple of tasks share the same logic you can extract this logic into a method. If multiple projects of a multi-project build share some logic you can define this method in the parent project. If the build logic gets too complex for being properly modeled by methods you want have an OO Model. Gradle makes this very easy. Just drop your classes in a certain directory and Gradle automatically compiles them and puts them in the classpath of your build script.
Here is a summary of the ways you can organise your build logic:
POGOs. You can declare and use plain old Groovy objects (POGOs) directly in your build script. The build script is written in Groovy, after all, and Groovy provides you with lots of excellent ways to organize code.
Inherited properties and methods. In a multi-project build, sub-projects inherit the properties and methods of their parent project.
Configuration injection. In a multi-project build, a project (usually the root project) can inject properties and methods into another project.
buildSrc project. Drop the source for your build classes into a certain directory and Gradle automatically compiles them and includes them in the classpath of your build script.
Shared scripts. Define common configuration in an external build, and apply the script to multiple projects, possibly across different builds.
Custom tasks. Put your build logic into a custom task, and reuse that task in multiple places.
Custom plugins. Put your build logic into a custom plugin, and apply that plugin to multiple projects. The plugin must be in the classpath of your build script. You can achieve this either by using build sources or by adding an external library that contains the plugin.
Execute an external build. Execute another Gradle build from the current build.
External libraries. Use external libraries directly in your build file.
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