implement ben manes' gradle versions plugin

Author: 05nelsonm

build.gradle

@@ -1,5 +1,3 @@
-apply plugin: 'org.jetbrains.dokka'
-
 buildscript {
     apply from: "$rootDir/gradle/dependencies.gradle"
 
@@ -13,6 +11,7 @@ buildscript {
         classpath plugin.kotlin.dokka
         classpath plugin.kotlin.gradle
         classpath plugin.mavenPublish
+        classpath plugin.gradleVersions
     }
 }
 
@@ -28,6 +27,53 @@ allprojects  {
     }
 }
 
+task clean(type: Delete) {
+    delete rootProject.buildDir
+}
+
+////////////////////////////////////////////////////////////////////////////
+/// Gradle Versions: https://github.com/ben-manes/gradle-versions-plugin ///
+////////////////////////////////////////////////////////////////////////////
+
+apply plugin: 'com.github.ben-manes.versions'
+
+def isNonStable = { String version ->
+    def stableKeyword = ['RELEASE', 'FINAL', 'GA'].any { it -> version.toUpperCase().contains(it) }
+    def regex = /^[0-9,.v-]+(-r)?$/
+    return !stableKeyword && !(version ==~ regex)
+}
+
+tasks.named("dependencyUpdates").configure {
+    checkForGradleUpdate = true
+
+    // Example 1: reject all non stable versions
+    rejectVersionIf {
+        isNonStable(candidate.version)
+    }
+
+    // Example 2: disallow release candidates as upgradable versions from stable versions
+    rejectVersionIf {
+        isNonStable(candidate.version) && !isNonStable(currentVersion)
+    }
+
+    // Example 3: using the full syntax
+    resolutionStrategy {
+        componentSelection {
+            all {
+                if (isNonStable(candidate.version) && !isNonStable(currentVersion)) {
+                    reject('Release candidate')
+                }
+            }
+        }
+    }
+}
+
+//////////////////////////////////////////////
+/// Dokka: https://github.com/Kotlin/dokka ///
+//////////////////////////////////////////////
+
+apply plugin: 'org.jetbrains.dokka'
+
 // Dokka's configuration.externalDocumentationLink.url setting for connecting methods/variables
 // in each module is quarky, especially when relying on Mkdocs to generate a website using the
 // Markdown files that are created. the `externalDocumentationLink.url` setting requires a
@@ -38,7 +84,3 @@ task fixDokkaDocLinks(type: Exec) {
     workingDir "$rootDir"
     commandLine "scripts/fix_dokka_doc_external_links.sh"
 }
-
-task clean(type: Delete) {
-  delete rootProject.buildDir
-}

gradle/dependencies.gradle

@@ -45,7 +45,7 @@ ext.deps = [
 
 ext.plugin = [
     androidGradle: "com.android.tools.build:gradle:4.1.0",
-    gradleVersions: "com.github.ben-manes:gradle-versions-plugin:0.20.0",
+    gradleVersions: "com.github.ben-manes:gradle-versions-plugin:0.33.0",
     kotlin: [
         dokka: "org.jetbrains.dokka:dokka-gradle-plugin:0.10.1",
         gradle: "org.jetbrains.kotlin:kotlin-gradle-plugin:${versions.kotlin}",