[KotlinTest] Start porting tests to Kotlin, port TestUtils (#59)

This sets up the compilation paths and moves the TestUtils class to Kotlin. Including a single test as a PoC.

First part of #58

Author: Nava2

build.gradle.kts

@@ -78,6 +78,14 @@ dependencies {
   testImplementation("org.assertj:assertj-core:3.24.2")
 }
 
+tasks.compileTestGroovy {
+  classpath += files(tasks.compileTestKotlin.flatMap { it.destinationDirectory })
+}
+
+tasks.testClasses {
+  dependsOn(tasks.compileTestGroovy)
+}
+
 tasks.check {
   dependsOn(tasks.named("projectHealth"))
 }

src/test/groovy/org/assertj/generator/gradle/IncrementalBuild.groovy

@@ -37,15 +37,15 @@ class IncrementalBuild {
     @Rule
     public final TemporaryFolder testProjectDir = new TemporaryFolder()
 
-    File buildFile
     private Path srcPackagePath
     private Path packagePath
     private File h1Java
     private File h2Java
 
     @Before
     void setup() {
-        buildFile = testProjectDir.newFile('build.gradle')
+        def buildFile = testProjectDir.newFile('build.gradle')
+        TestUtils.writeDefaultBuildFile(buildFile)
 
         File srcDir = testProjectDir.newFolder('src', 'main', 'java')
 
@@ -100,12 +100,6 @@ class IncrementalBuild {
 
     @Test
     void incremental_build_does_not_rebuild_everything() {
-        TestUtils.buildFile(buildFile, """                      
-            sourceSets {
-                main { assertJ {} }
-            }
-            """)
-
         def runner = GradleRunner.create()
                 .withProjectDir(testProjectDir.root)
                 .withDebug(true)
@@ -128,12 +122,6 @@ class IncrementalBuild {
 
     @Test
     void incremental_build_rebuild_changed_single_file_contents() {
-        TestUtils.buildFile(buildFile, """                      
-            sourceSets {
-                main { assertJ {} }
-            }
-            """)
-
         def runner = GradleRunner.create()
                 .withProjectDir(testProjectDir.root)
                 .withDebug(true)

src/test/groovy/org/assertj/generator/gradle/SimpleBuild.groovy

@@ -32,12 +32,12 @@ class SkipPackageInfo {
     @Rule
     public final TemporaryFolder testProjectDir = new TemporaryFolder()
 
-    File buildFile
-    Path generatedPackagePath
+    private Path generatedPackagePath
 
     @Before
     void setup() {
-        buildFile = testProjectDir.newFile('build.gradle')
+        def buildFile = testProjectDir.newFile('build.gradle')
+        TestUtils.writeDefaultBuildFile(buildFile)
 
         File srcDir = testProjectDir.newFolder('src', 'main', 'java')
 
@@ -112,12 +112,6 @@ class SkipPackageInfo {
 
     @Test
     void does_not_include_package_info_file() {
-        TestUtils.buildFile(buildFile, """                      
-            sourceSets {
-                main { assertJ {} }
-            }
-            """)
-
         def result = GradleRunner.create()
                 .withProjectDir(testProjectDir.root)
                 .withDebug(true)

src/test/groovy/org/assertj/generator/gradle/SkipPackageInfo.groovy

@@ -82,7 +82,7 @@ class EntryPointGeneration {
 
     @Test
     void change_generate_from_sourceSet() {
-        TestUtils.buildFile(buildFile, """
+        TestUtils.writeBuildFile(buildFile, """
             sourceSets {
                 main {
                     assertJ {
@@ -124,7 +124,7 @@ class EntryPointGeneration {
     @Test
     void change_generate_from_global() {
 
-        TestUtils.buildFile(buildFile, """
+        TestUtils.writeBuildFile(buildFile, """
             sourceSets {
                 main {
                     assertJ { 
@@ -162,7 +162,7 @@ class EntryPointGeneration {
 
     @Test
     void change_entry_point_package() {
-        TestUtils.buildFile(buildFile, """
+        TestUtils.writeBuildFile(buildFile, """
             sourceSets {
                 main {
                     assertJ {
@@ -199,7 +199,7 @@ class EntryPointGeneration {
 
     @Test
     void change_entry_point_package_and_entry_points() {
-        TestUtils.buildFile(buildFile, """
+        TestUtils.writeBuildFile(buildFile, """
             sourceSets {
                 main {
                     assertJ {

src/test/groovy/org/assertj/generator/gradle/TestUtils.groovy

@@ -24,7 +24,7 @@ import java.nio.file.Path
 import java.nio.file.Paths
 
 import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat
-import static org.assertj.generator.gradle.TestUtils.buildFile
+import static org.assertj.generator.gradle.TestUtils.writeBuildFile
 
 /**
  * Checks the behaviour of overriding globals in a project
@@ -63,7 +63,7 @@ class OutputDirectoryParameter {
 
     @Test
     void change_output_dir_locally() {
-        buildFile(buildFile, """            
+        writeBuildFile(buildFile, """            
             sourceSets {
                 main { 
                     assertJ {