implement compatibility support for gradle 4.10

README.md

@@ -54,7 +54,7 @@ Stand-alone examples are available for each of gradle's supported languages.
  * [Groovy](https://github.com/google/protobuf-gradle-plugin/tree/master/examples/exampleProject) ___(Default)___
    * Run `../../gradlew build` under the example directory to test it out.
  * [Kotlin](https://github.com/google/protobuf-gradle-plugin/tree/master/examples/exampleKotlinDslProject) ___(Experimental)___
-   * Run `./gradlew build` under the Kotlin example directory to test it out. This example is set up with Gradle 5.0, the minimum required version.
+   * Run `./gradlew build` under the Kotlin example directory to test it out. This example is set up with Gradle 4.10, the minimum required version.
 
 
 Directories that start with `testProject` can also serve as usage

examples/exampleKotlinDslProject/build.gradle.kts

@@ -3,7 +3,7 @@ import org.gradle.kotlin.dsl.provider.gradleKotlinDslOf
 
 // A minimal example Java project that uses the protobuf plugin.
 // To build it:
-// $ ../gradlew clean build
+// $ ./gradlew clean build
 plugins {
     java
     idea
@@ -61,10 +61,7 @@ protobuf {
     generateProtoTasks {
         ofSourceSet("main").forEach {
             it.plugins {
-                // Apply the "grpc" plugin whose spec is defined above, without
-                // options.  Note the braces cannot be omitted, otherwise the
-                // plugin will not be added. This is because of the implicit way
-                // NamedDomainObjectContainer binds the methods.
+                // Apply the "grpc" plugin whose spec is defined above, without options.
                 id("grpc")
             }
         }

src/main/groovy/com/google/protobuf/gradle/KtDslCompatibilityUtils.java

@@ -0,0 +1,34 @@
+package com.google.protobuf.gradle;
+
+import kotlin.Unit;
+import kotlin.jvm.functions.Function1;
+import org.gradle.api.NamedDomainObjectContainer;
+import org.gradle.kotlin.dsl.NamedDomainObjectContainerExtensionsKt;
+import org.gradle.kotlin.dsl.NamedDomainObjectContainerScope;
+
+public class KtDslCompatibilityUtils {
+
+    /**
+     * This method is used to delegate the NamedDomainObjectContainer configuration to
+     * to which ever kotlin-dsl ext implementation is available on the classpath.
+     *
+     * Since NamedDomainObjectContainerExtensionsKt.invoke is an inline extension function, our
+     * usages in 'ProtobufConfiguratorExts.kt' would use the byte code for which ever kotlin-dsl
+     * version we compiled against. This caused issues with providing compatibility with
+     * kotlin-dsl 1.0.0-rc3 and 1.0.4 (Stable).
+     *
+     * Since the kotlin compiler creates a static implementations of all extensions, we can create a
+     * delegating utility function that ensures we are not inline-ing our kotlin-dsl compilation
+     * target byte code.
+     *
+     * @param container Container to apply the scope configuration
+     * @param block A kotlin lambda to apply to the NamedDomainObjectContainerScope
+     * @return A NamedDomainObjectContainer with the block lambda applied to is NamedDomainObjectContainerScope
+     */
+    static <T> NamedDomainObjectContainer<T> configureNamedDomainObjectContainer(
+            NamedDomainObjectContainer<T> container,
+            Function1<? super NamedDomainObjectContainerScope<T>, Unit> block){
+
+        return NamedDomainObjectContainerExtensionsKt.invoke(container, block);
+    }
+}

src/main/groovy/com/google/protobuf/gradle/Utils.groovy

@@ -159,4 +159,5 @@ class Utils {
       }
     }
   }
+
 }

src/main/kotlin/com/google/protobuf/gradle/ProtobufConfiguratorExts.kt

@@ -85,7 +85,7 @@ fun ProtobufConfigurator.protoc(action: ExecutableLocator.() -> Unit) {
 
 fun ProtobufConfigurator.plugins(action: NamedDomainObjectContainerScope<ExecutableLocator>.() -> Unit) {
     plugins(closureOf<NamedDomainObjectContainer<ExecutableLocator>> {
-        NamedDomainObjectContainerScope.of(this).action()
+        KtDslCompatibilityUtils.configureNamedDomainObjectContainer<ExecutableLocator>(this, action)
     })
 }
 
@@ -95,13 +95,13 @@ fun ProtobufConfigurator.generateProtoTasks(action: ProtobufConfigurator.Generat
 
 fun GenerateProtoTask.builtins(action: NamedDomainObjectContainerScope<GenerateProtoTask.PluginOptions>.()->Unit) {
     builtins(closureOf<NamedDomainObjectContainer<GenerateProtoTask.PluginOptions>> {
-        NamedDomainObjectContainerScope.of(this).action()
+        KtDslCompatibilityUtils.configureNamedDomainObjectContainer<GenerateProtoTask.PluginOptions>(this, action)
     })
 }
 
 fun GenerateProtoTask.plugins(action: NamedDomainObjectContainerScope<GenerateProtoTask.PluginOptions>.()-> Unit) {
     plugins(closureOf<NamedDomainObjectContainer<GenerateProtoTask.PluginOptions>> {
-        NamedDomainObjectContainerScope.of(this).action()
+        KtDslCompatibilityUtils.configureNamedDomainObjectContainer<GenerateProtoTask.PluginOptions>(this, action)
     })
 }
 

src/test/groovy/com/google/protobuf/gradle/ProtobufKotlinDslPluginTest.groovy

@@ -9,7 +9,7 @@ import spock.lang.Specification
  * Unit tests for kotlin dsl extensions.
  */
 class ProtobufKotlinDslPluginTest extends Specification {
-  private static final List<String> GRADLE_VERSIONS = ["5.0"]
+  private static final List<String> GRADLE_VERSIONS = ["4.10", "5.0"]
 
   void "testProjectKotlinDsl should be successfully executed (java-only project)"() {
     given: "project from testProjectKotlinDslBase"