chore: Migrate to Kotlin DSL for Gradle

This change migrates the build configuration for Gradle in Groovy to
Kotlin, where possible. The scripts in the `gradle/` directory have not
been migrated to extensive use of dynamicism.

6 files changed, 56 insertions, 41 deletions

diff --git a/build.gradle b/build.gradle.kts
index 3d53b45c..01f95b26 100644
--- a/build.gradle
+++ b/build.gradle.kts
@@ -23,28 +23,29 @@
  */
 
 plugins {
-    id 'org.jetbrains.kotlin.jvm' version '1.3.30' apply false
-    id 'org.jetbrains.dokka' version '0.9.18' apply false
-    id 'org.jlleitschuh.gradle.ktlint' version '7.4.0' apply false
+    kotlin("jvm") version "1.3.30" apply false
+    id("org.jetbrains.dokka") version "0.9.18" apply false
+    id("org.jlleitschuh.gradle.ktlint") version "7.4.0" apply false
 }
 
 allprojects {
-    group = 'com.atlarge.opendc'
-    version = '2.0.0'
+    group = "com.atlarge.opendc"
+    version = "2.0.0"
 
-    ext {
-        junit_jupiter_version = '5.4.2'
-        junit_platform_version = '1.4.2'
-        github_url = "https://github.com/atlarge-research/${rootProject.name}"
-    }
+
+    extra["junitJupiterVersion"] = "5.4.2"
+    extra["junitPlatformVersion"] = "1.4.2"
+    extra["githubUrl"] = "https://github.com/atlarge-research/${rootProject.name}"
 }
 
-wrapper {
-    gradleVersion = '5.1'
+tasks.wrapper {
+    gradleVersion = "5.1"
 }
 
 // Wait for children to evaluate so we can configure tasks that are dependant on children
 project.evaluationDependsOnChildren()
 
-apply from: 'gradle/jacoco.gradle'
-apply from: 'gradle/dokka.gradle'
+apply {
+    from("gradle/jacoco.gradle")
+    from("gradle/dokka.gradle")
+}
diff --git a/gradle/dokka.gradle b/gradle/dokka.gradle
index e8e47d2d..576dbbeb 100644
--- a/gradle/dokka.gradle
+++ b/gradle/dokka.gradle
@@ -41,7 +41,7 @@ dokka {
 
     linkMapping {
         dir = rootProject.projectDir.absolutePath
-        url = "$github_url/tree/master"
+        url = "$githubUrl/tree/master"
         suffix = '#L'
     }
 }
diff --git a/odcsim-core/build.gradle b/odcsim-core/build.gradle.kts
index a0cd8450..1596f3c8 100644
--- a/odcsim-core/build.gradle
+++ b/odcsim-core/build.gradle.kts
@@ -23,19 +23,24 @@
  */
 
 /* Build configuration */
-apply from: '../gradle/kotlin.gradle'
-apply plugin: 'java-library'
+apply(from = "../gradle/kotlin.gradle")
+plugins {
+    `java-library`
+}
 
 /* Project configuration */
 repositories {
     jcenter()
 }
 
+val junitJupiterVersion: String by extra
+val junitPlatformVersion: String by extra
+
 dependencies {
-    implementation "org.jetbrains.kotlin:kotlin-stdlib"
+    implementation(kotlin("stdlib"))
 
-    testImplementation "org.junit.jupiter:junit-jupiter-api:$junit_jupiter_version"
-    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junit_jupiter_version"
-    testImplementation "org.junit.platform:junit-platform-launcher:$junit_platform_version"
-    testImplementation "com.nhaarman.mockitokotlin2:mockito-kotlin:2.0.0"
+    testImplementation("org.junit.jupiter:junit-jupiter-api:$junitJupiterVersion")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:$junitJupiterVersion")
+    testImplementation("org.junit.platform:junit-platform-launcher:$junitPlatformVersion")
+    testImplementation("com.nhaarman.mockitokotlin2:mockito-kotlin:2.0.0")
 }
diff --git a/odcsim-engine-omega/build.gradle b/odcsim-engine-omega/build.gradle.kts
index cefd3e20..347e2bb4 100644
--- a/odcsim-engine-omega/build.gradle
+++ b/odcsim-engine-omega/build.gradle.kts
@@ -23,23 +23,28 @@
  */
 
 /* Build configuration */
-apply from: '../gradle/kotlin.gradle'
-apply plugin: 'java-library'
+apply(from = "../gradle/kotlin.gradle")
+plugins {
+    `java-library`
+}
 
 /* Project configuration */
 repositories {
     jcenter()
 }
 
+val junitJupiterVersion: String by extra
+val junitPlatformVersion: String by extra
+
 dependencies {
-    api project(':odcsim-core')
+    api(project(":odcsim-core"))
 
-    implementation "org.jetbrains.kotlin:kotlin-stdlib"
-    implementation "io.github.microutils:kotlin-logging:1.6.20"
+    implementation(kotlin("stdlib"))
+    implementation("io.github.microutils:kotlin-logging:1.6.20")
 
-    testApi project(':odcsim-engine-tests')
-    testImplementation "org.junit.jupiter:junit-jupiter-api:$junit_jupiter_version"
-    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junit_jupiter_version"
-    testImplementation "org.junit.platform:junit-platform-launcher:$junit_platform_version"
-    testRuntimeOnly "org.slf4j:slf4j-simple:1.7.25"
+    testCompile(project(":odcsim-engine-tests"))
+    testImplementation("org.junit.jupiter:junit-jupiter-api:$junitJupiterVersion")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:$junitJupiterVersion")
+    testImplementation("org.junit.platform:junit-platform-launcher:$junitPlatformVersion")
+    testRuntimeOnly("org.slf4j:slf4j-simple:1.7.25")
 }
diff --git a/odcsim-engine-tests/build.gradle b/odcsim-engine-tests/build.gradle.kts
index da568319..8b19019a 100644
--- a/odcsim-engine-tests/build.gradle
+++ b/odcsim-engine-tests/build.gradle.kts
@@ -23,17 +23,21 @@
  */
 
 /* Build configuration */
-apply from: '../gradle/kotlin.gradle'
-apply plugin: 'java-library'
+apply(from = "../gradle/kotlin.gradle")
+plugins {
+    `java-library`
+}
 
 /* Project configuration */
 repositories {
     jcenter()
 }
 
+val junitJupiterVersion: String by extra
+
 dependencies {
-    api project(':odcsim-core')
+    api(project(":odcsim-core"))
 
-    implementation "org.jetbrains.kotlin:kotlin-stdlib"
-    implementation "org.junit.jupiter:junit-jupiter-api:$junit_jupiter_version"
+    implementation(kotlin("stdlib"))
+    implementation("org.junit.jupiter:junit-jupiter-api:$junitJupiterVersion")
 }
diff --git a/settings.gradle b/settings.gradle.kts
index 9ae9a5ab..b7657f70 100644
--- a/settings.gradle
+++ b/settings.gradle.kts
@@ -21,8 +21,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-rootProject.name = 'opendc-simulator'
+rootProject.name = "opendc-simulator"
 
-include 'odcsim-core'
-include 'odcsim-engine-tests'
-include 'odcsim-engine-omega'
+include(":odcsim-core")
+include(":odcsim-engine-tests")
+include(":odcsim-engine-omega")