[gradle] Enabling up-to-date checks and gradle caching for openapigen…

…erator tasks (#6716)

appveyor.yml

@@ -15,14 +15,14 @@ install:
   # install gradle
   - ps: |
       Add-Type -AssemblyName System.IO.Compression.FileSystem
-      if (!(Test-Path -Path "C:\gradle" )) {
+      if (!(Test-Path -Path "C:\gradle\gradle-5.6.4" )) {
         (new-object System.Net.WebClient).DownloadFile(
-          'https://services.gradle.org/distributions/gradle-5.3.1-bin.zip',
+          'https://services.gradle.org/distributions/gradle-5.6.4-bin.zip',
           'C:\gradle-bin.zip'
         )
         [System.IO.Compression.ZipFile]::ExtractToDirectory("C:\gradle-bin.zip", "C:\gradle")
       }
-  - cmd: SET PATH=C:\maven\apache-maven-3.2.5\bin;C:\gradle\gradle-5.3.1\bin;%JAVA_HOME%\bin;%PATH%
+  - cmd: SET PATH=C:\maven\apache-maven-3.2.5\bin;C:\gradle\gradle-5.6.4\bin;%JAVA_HOME%\bin;%PATH%
   - cmd: SET MAVEN_OPTS=-Xmx4g
   - cmd: SET JAVA_OPTS=-Xmx4g
   - cmd: SET M2_HOME=C:\maven\apache-maven-3.2.5

modules/openapi-generator-gradle-plugin/README.adoc

@@ -61,6 +61,35 @@ task validateBadSpec(type: org.openapitools.generator.gradle.plugin.tasks.Valida
 task validateSpecs(dependsOn: ['validateGoodSpec', 'validateBadSpec'])
 ----
 
+[NOTE]
+====
+The tasks support Gradle Up-To-Date checking and Gradle Cache. Enable caching globally by setting `org.gradle.caching=true` in the `gradle.settings`
+file or by passing the command line property `--build-cache` when executing on the command line.
+
+Disable up-to-date checks and caching by setting the following property when using the extension:
+
+.Disable caching for extension
+[source,groovy]
+----
+tasks.withType(org.openapitools.generator.gradle.plugin.tasks.GenerateTask) {
+    outputs.upToDateWhen { false }
+    outputs.cacheIf { false }
+}
+----
+Disable up-to-date checks and caching for a custom task:
+
+.Disable caching for custom task
+[source,groovy]
+----
+task validateGoodSpec(type: org.openapitools.generator.gradle.plugin.tasks.ValidateTask){
+    outputs.upToDateWhen { false }
+    outputs.cacheIf { false }
+
+    inputSpec = "$rootDir/petstore-v3.0.yaml".toString()
+}
+----
+====
+
 == Plugin Setup
 
 //# RELEASE_VERSION

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

@@ -1,5 +1,5 @@
 #Thu Jan 30 22:14:34 EST 2020
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists

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

@@ -1,18 +1,18 @@
 # Local Spec Sample
 
-This example assumes you have Gradle 4.7+ installed. No gradle wrapper is provided in samples.
+This example assumes you have Gradle 5.6.4+ installed. No gradle wrapper is provided in samples.
 
-First, publish the openapi-generator-gradle-plugin locally via `./gradlew assemble install` in the module directory.
+First, publish the openapi-generator-gradle-plugin locally via `./gradlew assemble publishToMavenLocal` in the module directory.
 
 Then, run the following tasks in this example directory.
 
 ```bash
-gradle openApiGenerate
-gradle openApiMeta
-gradle openApiValidate
-gradle buildGoSdk
-gradle buildDotnetSdk
-gradle generateGoWithInvalidSpec
+gradle openApiGenerate              # expected outcome: BUILD SCCESSFUL
+gradle openApiMeta                  # expected outcome: BUILD SCCESSFUL
+gradle openApiValidate              # expected outcome: BUILD FAILED 
+gradle buildGoSdk                   # expected outcome: BUILD SCCESSFUL
+gradle buildDotnetSdk               # expected outcome: BUILD SCCESSFUL
+gradle generateGoWithInvalidSpec    # expected outcome: BUILD FAILED 
 ```
 
 The samples can be tested against other versions of the plugin using the `openApiGeneratorVersion` property. For example:

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

@@ -55,9 +55,9 @@ class OpenApiGeneratorPlugin : Plugin<Project> {
             )
 
             val generators = extensions.create(
-                "openApiGenerators",
-                OpenApiGeneratorGeneratorsExtension::class.java,
-                project
+                    "openApiGenerators",
+                    OpenApiGeneratorGeneratorsExtension::class.java,
+                    project
             )
 
             generate.outputDir.set("$buildDir/generate-resources/main")

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

@@ -317,7 +317,7 @@ open class OpenApiGeneratorGenerateExtension(project: Project) {
     }
 
     @Suppress("MemberVisibilityCanBePrivate")
-    fun applyDefaults(){
+    fun applyDefaults() {
         releaseNote.set("Minor update")
         modelNamePrefix.set("")
         modelNameSuffix.set("")