[gradle plugin] Support Gradle 4.10 (#1011)

* Support Gradle 4.10

Gradle 4.10 is bundled with Kotlin 1.60 and Kotlin DSL 1.0-rc1. The new
Kotlin DSL isn't binary compatible with the `tasks` registration used in
this plugin.

Updating to Kotlin DSL 1.0-rc1 with no other changes would require users
to update to Gradle 4.10.

As a workaround, I've modified the tasks registration being done in
OpenApiGeneratorPlugin.kt, so rather than using the Kotlin DSL's invoke,
it creates tasks manually against the TasksContainer. This works locally
with Gradle 4.7+ for all scenarios in the sample (samples/local-spec).
There may be edge cases that I'm unaware of, and we may want to consider
defining the minimum supported Gradle version of 4.10 in the next major
version of openapi-generator-gradle-plugin if we experience those cases.

* Uncomment snapshots repo (commented it during local testing)

* update pom.xml for exec gradle plugin

modules/openapi-generator-gradle-plugin/build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.2.41'
+    ext.kotlin_version = '1.2.60'
     repositories {
         mavenCentral()
         maven {
@@ -14,7 +14,7 @@ buildscript {
     }
     dependencies {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-        classpath "gradle.plugin.org.gradle.kotlin:gradle-kotlin-dsl-plugins:0.17.5"
+        classpath "gradle.plugin.org.gradle.kotlin:gradle-kotlin-dsl-plugins:1.0-rc-3"
     }
 }
 

modules/openapi-generator-gradle-plugin/gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.7-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10-rc-1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

modules/openapi-generator-gradle-plugin/pom.xml

@@ -54,7 +54,7 @@
                 <artifactId>gradle-maven-plugin</artifactId>
                 <version>1.0.8</version>
                 <configuration>
-                    <gradleVersion>4.7</gradleVersion>
+                    <gradleVersion>4.10-rc-1</gradleVersion>
                     <args>
                         <arg>-P openApiGeneratorVersion=${project.version}</arg>
                     </args>

modules/openapi-generator-gradle-plugin/samples/local-spec/README.md

@@ -17,5 +17,5 @@ gradle generateGoWithInvalidSpec
 The samples can be tested against other versions of the plugin using the `openApiGeneratorVersion` property. For example:
 
 ```bash
-gradle -PopenApiGeneratorVersion=3.2.3 openApiValidate
+gradle -PopenApiGeneratorVersion=3.3.0 openApiValidate
 ```

modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/OpenApiGeneratorPlugin.kt

@@ -18,7 +18,6 @@ package org.openapitools.generator.gradle.plugin
 
 import org.gradle.api.Plugin
 import org.gradle.api.Project
-import org.gradle.kotlin.dsl.invoke
 import org.openapitools.generator.gradle.plugin.extensions.OpenApiGeneratorGenerateExtension
 import org.openapitools.generator.gradle.plugin.extensions.OpenApiGeneratorMetaExtension
 import org.openapitools.generator.gradle.plugin.extensions.OpenApiGeneratorValidateExtension
@@ -56,12 +55,13 @@ class OpenApiGeneratorPlugin : Plugin<Project> {
 
             generate.outputDir.set("$buildDir/generate-resources/main")
 
-            tasks {
+            tasks.apply {
-                "openApiGenerators"(GeneratorsTask::class) {
+                create("openApiGenerators", GeneratorsTask::class.java) {
                     group = pluginGroup
                     description = "Lists generators available via Open API Generators."
                 }
-                "openApiMeta"(MetaTask::class) {
+
+                create("openApiMeta", MetaTask::class.java) {
                     group = pluginGroup
                     description = "Generates a new generator to be consumed via Open API Generator."
 
@@ -69,13 +69,15 @@ class OpenApiGeneratorPlugin : Plugin<Project> {
                     packageName.set(meta.packageName)
                     outputFolder.set(meta.outputFolder)
                 }
-                "openApiValidate"(ValidateTask::class) {
+
+                create("openApiValidate", ValidateTask::class.java) {
                     group = pluginGroup
                     description = "Validates an Open API 2.0 or 3.x specification document."
 
                     inputSpec.set(validate.inputSpec)
                 }
-                "openApiGenerate"(GenerateTask::class) {
+
+                create("openApiGenerate", GenerateTask::class.java) {
                     group = pluginGroup
                     description = "Generate code via Open API Tools Generator for Open API 2.0 or 3.x specification documents."