add plugin tests

src/main/kotlin/com/jaredsburrows/license/project.kt

@@ -0,0 +1,8 @@
+package com.jaredsburrows.license
+
+import org.gradle.api.Project
+
+/** Returns true if plugin exists in project */
+internal fun Project.hasPlugin(list: List<String>): Boolean {
+  return list.find { project.plugins.hasPlugin(it) } != null
+}

src/main/kotlin/com/jaredsburrows/license/projectAndroid.kt

@@ -7,14 +7,29 @@ import com.android.build.gradle.FeatureExtension
 import com.android.build.gradle.FeaturePlugin
 import com.android.build.gradle.LibraryExtension
 import com.android.build.gradle.LibraryPlugin
+import com.android.build.gradle.TestExtension
+import com.android.build.gradle.TestPlugin
 import com.android.build.gradle.api.BaseVariant
 import org.gradle.api.DomainObjectSet
 import org.gradle.api.Project
 import java.util.Locale
 
 /** Returns true if Android Gradle project */
 internal fun Project.isAndroidProject(): Boolean {
-  return project.plugins.hasPlugin("android")
+  return hasPlugin(
+    listOf(
+      // AppPlugin
+      "android",
+      "com.android.application",
+      // FeaturePlugin
+      "com.android.feature",
+      // LibraryPlugin
+      "android-library",
+      "com.android.library",
+      // TestPlugin
+      "com.android.test",
+    )
+  )
 }
 
 /**
@@ -23,6 +38,7 @@ internal fun Project.isAndroidProject(): Boolean {
  * AppPlugin - "android", "com.android.application"
  * FeaturePlugin - "com.android.feature"
  * LibraryPlugin - "android-library", "com.android.library"
+ * TestPlugin - "com.android.test"
  */
 internal fun Project.configureAndroidProject() {
   project.plugins.all {
@@ -43,6 +59,11 @@ internal fun Project.configureAndroidProject() {
           configureVariant(libraryVariants)
         }
       }
+      is TestPlugin -> {
+        project.extensions.getByType(TestExtension::class.java).run {
+          configureVariant(applicationVariants)
+        }
+      }
     }
   }
 }

src/main/kotlin/com/jaredsburrows/license/projectJava.kt

@@ -4,7 +4,15 @@ import org.gradle.api.Project
 
 /** Returns true if Java Gradle project */
 internal fun Project.isJavaProject(): Boolean {
-  return project.plugins.hasPlugin("java")
+  return hasPlugin(
+    listOf(
+      "application", // JavaApplicationPlugin
+      "groovy", // GroovyPlugin
+      "java", // JavaPlugin, also applies JavaBasePlugin
+      "java-library", // JavaLibraryPlugin, also applies JavaPlugin
+      "scala", // ScalaPlugin
+    )
+  )
 }
 
 /**

src/test/groovy/com/jaredsburrows/license/LicensePluginSpec.groovy

@@ -0,0 +1,185 @@
+package com.jaredsburrows.license
+
+
+import org.junit.Rule
+import org.junit.rules.TemporaryFolder
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
+import static test.TestUtils.gradleWithCommand
+
+final class LicensePluginSpec extends Specification {
+  @Rule public final TemporaryFolder testProjectDir = new TemporaryFolder()
+  private List<File> pluginClasspath
+  private String classpathString
+  private File buildFile
+
+  def 'setup'() {
+    def pluginClasspathResource = getClass().classLoader.getResource('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) }
+    classpathString = pluginClasspath
+      .collect { it.absolutePath.replace('\\', '\\\\') } // escape backslashes in Windows paths
+      .collect { "'$it'" }
+      .join(", ")
+    buildFile = testProjectDir.newFile('build.gradle')
+  }
+
+  def 'apply with buildscript'() {
+    given:
+    buildFile <<
+      """
+      buildscript {
+        repositories {
+          mavenCentral()
+          google()
+        }
+
+        dependencies {
+          classpath files($classpathString)
+        }
+      }
+
+      apply plugin: 'java'
+      apply plugin: 'com.jaredsburrows.license'
+      """
+
+    when:
+    def result = gradleWithCommand(testProjectDir.root, 'licenseReport', '-s')
+
+    then:
+    result.task(':licenseReport').outcome == SUCCESS
+  }
+
+  def 'apply with plugins'() {
+    given:
+    buildFile <<
+      """
+      plugins {
+        id 'java'
+        id 'com.jaredsburrows.license'
+      }
+      """
+
+    when:
+    def result = gradleWithCommand(testProjectDir.root, 'licenseReport', '-s')
+
+    then:
+    result.task(':licenseReport').outcome == SUCCESS
+  }
+
+  @Unroll def 'apply with allowed java plugins: #javaPlugin'() {
+    given:
+    buildFile <<
+      """
+      plugins {
+        id '${javaPlugin}'
+        id 'com.jaredsburrows.license'
+      }
+      """
+
+    when:
+    def result = gradleWithCommand(testProjectDir.root, 'licenseReport', '-s')
+
+    then:
+    result.task(':licenseReport').outcome == SUCCESS
+
+    where:
+    javaPlugin << [
+      'application', // JavaApplicationPlugin
+      'groovy', // GroovyPlugin
+      'java', // JavaPlugin
+      'java-library', // JavaLibraryPlugin
+      'scala', // ScalaPlugin
+    ]
+  }
+
+  @Unroll def 'apply with allowed android plugins: #androidPlugin'() {
+    given:
+    testProjectDir.newFile('settings.gradle') <<
+      """
+      include 'subproject'
+      """
+
+    testProjectDir.newFolder('subproject')
+
+    testProjectDir.newFile('subproject/build.gradle') <<
+      """
+     buildscript {
+        repositories {
+          mavenCentral()
+          google()
+        }
+
+        dependencies {
+          classpath "com.android.tools.build:gradle:3.6.4"
+          classpath files($classpathString)
+        }
+      }
+
+      apply plugin: 'com.android.application'
+      apply plugin: 'com.jaredsburrows.license'
+
+      android {
+        compileSdkVersion 28
+
+        defaultConfig {
+          if (project.plugins.hasPlugin("com.android.application")) applicationId 'com.example'
+          if (project.plugins.hasPlugin("com.android.test")) targetProjectPath ':subproject'
+        }
+      }
+      """
+
+    buildFile <<
+      """
+      buildscript {
+        repositories {
+          mavenCentral()
+          google()
+        }
+
+        dependencies {
+          classpath "com.android.tools.build:gradle:3.6.4"
+          classpath files($classpathString)
+        }
+      }
+
+      apply plugin: '${androidPlugin}'
+      apply plugin: 'com.jaredsburrows.license'
+
+      android {
+        compileSdkVersion 28
+
+        defaultConfig {
+          if (project.plugins.hasPlugin("com.android.application")) applicationId 'com.example'
+          if (project.plugins.hasPlugin("com.android.test")) targetProjectPath ':subproject'
+        }
+      }
+      """
+
+    when:
+    def result = gradleWithCommand(testProjectDir.root, 'licenseDebugReport', '-s')
+
+    then:
+    result.task(':licenseDebugReport').outcome == SUCCESS
+
+    where:
+    androidPlugin << [
+      // AppPlugin
+      'android',
+      'com.android.application',
+      // FeaturePlugin
+      'com.android.feature',
+      // LibraryPlugin
+      'android-library',
+      'com.android.library',
+      // TestPlugin
+      'com.android.test',
+    ]
+  }
+}