Add ScalaIDE container to the Eclipse classpath for Scala projects

subprojects/docs/src/docs/release/notes.md

@@ -104,6 +104,10 @@ Groovy: [`ScalaCompile.fork = true`](dsl/org.gradle.api.tasks.scala.ScalaCompile
 activates external compilation, and [`ScalaCompile.forkOptions`](dsl/org.gradle.api.tasks.scala.ScalaCompile.html#org.gradle.api.tasks.scala.ScalaCompile:forkOptions)
 allows to adjust memory settings.
 
+### ScalaIDE integration
+
+The [Eclipse Plugin](http://gradle.org/docs/current/userguide/eclipse_plugin.html) has improved Scala support by generating classpath entries for the [Scala IDE](http://scala-ide.org).
+
 ## Promoted features
 
 Promoted features are features that were incubating in previous versions of Gradle but are now supported and subject to our backwards compatibility policy.
@@ -210,5 +214,6 @@ We would like to thank the following community members for making contributions
 * Gerd Aschemann - fixes for `application` plugins generated shell scripts (GRADLE-2501)
 * Cruz Fernandez - fixes to the properties sample project
 * Fadeev Alexandr - fixes for Gradle Daemon on Win 7 when `PATH` env var is not set (GRADLE-2461)
+* Ben Manes - ScalaIDE integration
 
 We love getting contributions from the Gradle community. For information on contributing, please see (gradle.org/contribute)[http://gradle.org/contribute]

subprojects/docs/src/docs/userguide/eclipsePlugin.xml

@@ -44,7 +44,7 @@
             <td><link linkend="groovy_plugin">Groovy</link></td><td>Adds Groovy configuration to <filename>.project</filename> file.</td>
         </tr>
         <tr>
-                <td><link linkend="scala_plugin">Scala</link></td><td>Adds Scala support to <filename>.project</filename> file.</td>
+            <td><link linkend="scala_plugin">Scala</link></td><td>Adds Scala support to <filename>.project</filename> and <filename>.classpath</filename> files.</td>
         </tr>
         <tr>
             <td><link linkend="war_plugin">War</link></td><td>Adds web application support to <filename>.project</filename> file.

subprojects/ide/src/integTest/groovy/org/gradle/plugins/ide/eclipse/EclipseClasspathIntegrationTest.groovy

@@ -631,4 +631,47 @@ dependencies {
         libraries[1].assertHasJar(file('unresolved dependency - i.dont Exist 1.0'))
         libraries[2].assertHasJar(localJar)
     }
+
+    @Test
+    void classpathIsConfiguredForScalaIDE() {
+        //given
+        def scalaCompilerJar = mavenRepo.module('org.scala-lang', 'scala-compiler', '2.9.2').publish().artifactFile
+        def scalaLibraryJar = mavenRepo.module('org.scala-lang', 'scala-library', '2.9.2').publish().artifactFile
+        def scalaSwingJar = mavenRepo.module('org.scala-lang', 'scala-swing', '2.9.2').publish().artifactFile
+        def scalaDbcJar = mavenRepo.module('org.scala-lang', 'scala-dbc', '2.9.2').publish().artifactFile
+        def scalaJlineJar = mavenRepo.module('org.scala-lang', 'jline', '2.9.2').publish().artifactFile
+
+        //when
+        runEclipseTask """
+apply plugin: 'scala'
+apply plugin: 'eclipse'
+
+repositories {
+    maven { url "${mavenRepo.uri}" }
+    mavenCentral()
+}
+
+dependencies {
+    def libraries = [
+        scala_compiler: "org.scala-lang:scala-compiler:2.9.2",
+        scala_library: "org.scala-lang:scala-library:2.9.2",
+        scala_swing: "org.scala-lang:scala-swing:2.9.2",
+        scala_dbc: "org.scala-lang:scala-dbc:2.9.2",
+        scala_jline: "org.scala-lang:jline:2.9.2",
+    ]
+
+    scalaTools libraries.scala_compiler
+    scalaTools libraries.scala_library
+    scalaTools libraries.scala_jline
+
+    compile libraries.scala_library
+    compile libraries.scala_swing
+    compile libraries.scala_dbc
+}
+"""
+
+        //then
+        assert classpath.libs.isEmpty()
+        assert classpath.containers == ['org.eclipse.jdt.launching.JRE_CONTAINER', 'org.scala-ide.sdt.launching.SCALA_CONTAINER']
+    }
 }

subprojects/ide/src/main/groovy/org/gradle/plugins/ide/eclipse/EclipsePlugin.groovy

@@ -16,6 +16,7 @@
 package org.gradle.plugins.ide.eclipse
 
 import org.gradle.api.Project
+import org.gradle.api.artifacts.Dependency
 import org.gradle.internal.reflect.Instantiator
 import org.gradle.api.plugins.GroovyBasePlugin
 import org.gradle.api.plugins.JavaBasePlugin
@@ -143,6 +144,20 @@ class EclipsePlugin extends IdePlugin {
                         project.sourceSets.main.output.dirs + project.sourceSets.test.output.dirs
                     }
                 }
+                project.plugins.withType(ScalaBasePlugin) {
+                    classpath.containers 'org.scala-ide.sdt.launching.SCALA_CONTAINER'
+
+                    //remove the dependencies also provided by ScalaIDE
+                    project.gradle.projectsEvaluated {
+                        def provided = ["scala-library", "scala-swing", "scala-dbc"] as Set
+                        def dependencies = project.configurations.collectMany {
+                            it.getAllDependencies()
+                        }.grep{ it.name in provided }.unique().toArray([] as Dependency[])
+                        if (dependencies != []) {
+                            classpath.minusConfigurations += project.configurations.detachedConfiguration(dependencies)
+                        }
+                    }
+                }
             }
         }
     }

subprojects/ide/src/test/groovy/org/gradle/plugins/ide/eclipse/EclipsePluginTest.groovy

@@ -45,8 +45,8 @@ class EclipsePluginTest extends Specification {
 
     def applyToJavaProject_shouldOnlyHaveProjectAndClasspathTaskForJava() {
         when:
-        project.apply(plugin: 'java-base')
         eclipsePlugin.apply(project)
+        project.apply(plugin: 'java-base')
 
         then:
         assertThatCleanEclipseDependsOn(project, project.cleanEclipseProject)
@@ -63,28 +63,31 @@ class EclipsePluginTest extends Specification {
     }
 
     def applyToScalaProject_shouldHaveProjectAndClasspathTaskForScala() {
+        def scalaIdeContainer = ['org.scala-ide.sdt.launching.SCALA_CONTAINER']
+
         when:
-        project.apply(plugin: 'scala-base')
         eclipsePlugin.apply(project)
+        project.apply(plugin: 'scala-base')
+        project.gradle.buildListenerBroadcaster.projectsEvaluated(project.gradle)
 
         then:
         assertThatCleanEclipseDependsOn(project, project.cleanEclipseProject)
         assertThatCleanEclipseDependsOn(project, project.cleanEclipseClasspath)
         checkEclipseProjectTask([new BuildCommand('org.scala-ide.sdt.core.scalabuilder')],
                 ['org.scala-ide.sdt.core.scalanature', 'org.eclipse.jdt.core.javanature'])
-        checkEclipseClasspath([])
+        checkEclipseClasspath([], scalaIdeContainer)
 
         when:
         project.apply(plugin: 'scala')
 
         then:
-        checkEclipseClasspath([project.configurations.testRuntime])
+        checkEclipseClasspath([project.configurations.testRuntime], scalaIdeContainer)
     }
 
     def applyToGroovyProject_shouldHaveProjectAndClasspathTaskForGroovy() {
         when:
-        project.apply(plugin: 'groovy-base')
         eclipsePlugin.apply(project)
+        project.apply(plugin: 'groovy-base')
 
         then:
         assertThatCleanEclipseDependsOn(project, project.cleanEclipseProject)
@@ -134,14 +137,14 @@ class EclipsePluginTest extends Specification {
         assert eclipseProjectTask.outputFile == project.file('.project')
     }
 
-    private void checkEclipseClasspath(def configurations) {
+    private void checkEclipseClasspath(def configurations, def additionalContainers = []) {
         GenerateEclipseClasspath eclipseClasspath = project.tasks.eclipseClasspath
         assert eclipseClasspath instanceof GenerateEclipseClasspath
         assert project.tasks.eclipse.taskDependencies.getDependencies(project.tasks.eclipse).contains(eclipseClasspath)
         assert eclipseClasspath.sourceSets == project.sourceSets
         assert eclipseClasspath.plusConfigurations == configurations
         assert eclipseClasspath.minusConfigurations == []
-        assert eclipseClasspath.containers == ['org.eclipse.jdt.launching.JRE_CONTAINER'] as Set
+        assert eclipseClasspath.containers == ['org.eclipse.jdt.launching.JRE_CONTAINER'] + additionalContainers as Set
         assert eclipseClasspath.outputFile == project.file('.classpath')
         assert eclipseClasspath.defaultOutputDir == new File(project.projectDir, 'bin')
     }