Fix compiler plugin path not working when library is used as a jar.

Author: tschuchortdev

README.md

@@ -47,7 +47,7 @@ Configure compilation
         sources = listOf(kotlinSource, javaSource)
 
         // pass your own instance of an annotation processor
-        annotationProcessors = listOf(MyAnnotationProcessor())) 
+        annotationProcessors = listOf(MyAnnotationProcessor()) 
 
         inheritClasspath = true
         messageOutputStream = System.out // see diagnostics in real time
@@ -98,7 +98,7 @@ Add dependency to your module `build.gradle` file:
 ```Groovy
 dependencies {
         // ...
-	implementation 'com.github.tschuchortdev:kotlin-compile-testing:1.1.0'
+	implementation 'com.github.tschuchortdev:kotlin-compile-testing:1.1.2'
 }
 ```
 

build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.3.21'
+    ext.kotlin_version = '1.3.31'
 
     repositories {
         mavenCentral()
@@ -22,7 +22,7 @@ apply plugin: 'idea'
 apply plugin: 'maven'
 
 group 'com.tschuchort'
-version '1.1.0'
+version '1.1.2'
 
 sourceCompatibility = 1.8
 

gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.3-all.zip

src/main/kotlin/com/tschuchort/compiletesting/KotlinCompilation.kt

@@ -33,6 +33,7 @@ import org.jetbrains.kotlin.config.JvmTarget
 import org.jetbrains.kotlin.config.Services
 import java.io.*
 import java.lang.RuntimeException
+import java.net.URI
 import java.net.URLClassLoader
 import java.nio.file.Files
 import java.nio.file.Path
@@ -462,10 +463,21 @@ class KotlinCompilation {
 			}
 		}
 
-		val resourcesPath = this::class.java.classLoader
-				.getResource("META-INF/services/org.jetbrains.kotlin.compiler.plugin.ComponentRegistrar").path
-				.removeSuffix("META-INF/services/org.jetbrains.kotlin.compiler.plugin.ComponentRegistrar")
-		
+		val resourcesUri = URI.create(
+			this::class.java.classLoader
+				.getResource("META-INF/services/org.jetbrains.kotlin.compiler.plugin.ComponentRegistrar")
+				.toString().removeSuffix("/META-INF/services/org.jetbrains.kotlin.compiler.plugin.ComponentRegistrar")
+		)
+
+		val resourcesPath = when(resourcesUri.scheme) {
+			"jar" -> resourcesUri.schemeSpecificPart.removeSurrounding("file:", "!")
+			"file" -> resourcesUri.schemeSpecificPart
+			else -> throw IllegalStateException(
+				"Don't know how to handle protocol of ComponentRegistrar plugin. " +
+						"Did you include this library in a weird way? Only jar and file path are supported."
+			)
+		}.removePrefix("/")
+
 		val k2JvmArgs = commonK2JVMArgs().also {
 			it.freeArgs = sourcePaths