using manual classpath injection to be able to apply android plugin first

Author: dcendents

build.gradle

@@ -34,6 +34,19 @@ sourceSets {
 	}
 }
 
+// Write the plugin's classpath to a file to share with the tests
+task createClasspathManifest {
+    def outputDir = file("$buildDir/$name")
+
+    inputs.files sourceSets.main.runtimeClasspath
+    outputs.dir outputDir
+
+    doLast {
+        outputDir.mkdirs()
+        file("$outputDir/plugin-classpath.txt").text = sourceSets.main.runtimeClasspath.join("\n")
+    }
+}
+
 dependencies {
 	jacocoRuntime "org.jacoco:org.jacoco.agent:${jacoco.toolVersion}:runtime"
 
@@ -80,6 +93,8 @@ dependencies {
 		dependency 'org.sonatype.aether:aether-connector-wagon:1.13.1@jar'
 	}
 
+	testRuntime files(createClasspathManifest)
+
 	testCompile('org.spockframework:spock-core:1.0-groovy-2.4') {
         exclude module: 'groovy-all'
     }

src/test/groovy/org/gradle/api/plugins/AndroidMavenPluginIT.groovy

@@ -18,6 +18,7 @@ class AndroidMavenPluginIT extends Specification {
 	@Shared def buildDir = "${System.properties['buildDir']}"
 
     @Rule final TemporaryFolder testProjectDir = new TemporaryFolder()
+	List<File> pluginClasspath
 
 	File androidManifest
 	File settingsFile
@@ -32,6 +33,13 @@ class AndroidMavenPluginIT extends Specification {
         settingsFile = testProjectDir.newFile('settings.gradle')
 		gradlePropertiesFile = testProjectDir.newFile('gradle.properties')
         buildFile = testProjectDir.newFile('build.gradle')
+
+        def pluginClasspathResource = getClass().classLoader.findResource("plugin-classpath.txt")
+        if (pluginClasspathResource == null) {
+            throw new IllegalStateException("Did not find plugin classpath resource, run `testClasses` build task.")
+        }
+
+        pluginClasspath = pluginClasspathResource.readLines().collect { new File(it) }
     }
 
 	@Unroll
@@ -47,6 +55,11 @@ class AndroidMavenPluginIT extends Specification {
 
 		gradlePropertiesFile << "org.gradle.jvmargs=-javaagent:${jacocoRuntime}=destfile=${buildDir}/jacoco/testKit-${gradleVersion}.exec"
 
+        def classpathString = pluginClasspath
+            .collect { it.absolutePath.replace('\\', '/') }
+            .collect { "'$it'" }
+            .join(", ")
+
 		def uri = testProjectDir.root.toURI()
         buildFile << """
 			buildscript {
@@ -60,14 +73,12 @@ class AndroidMavenPluginIT extends Specification {
 
 				dependencies {
 					classpath "com.android.tools.build:gradle:${androidGradleBuildVersion}"
+					classpath files(${classpathString})
 				}
 			}
 			
-			plugins {
-				id "com.github.dcendents.android-maven"
-			}
-
 			apply plugin: 'com.android.library'
+			apply plugin: 'com.github.dcendents.android-maven'
 
 			group = 'org.test'
 			version = '1.0'