Reject non-stable versions for dependencyUpdates

build.gradle

@@ -49,6 +49,18 @@ dependencies {
     testImplementation("org.skyscreamer:jsonassert:1.5.1")
 }
 
+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 {
+    rejectVersionIf {
+        isNonStable(it.candidate.version)
+    }
+}
+
 publishing {
     publications {
         mavenJava(MavenPublication) {
@@ -106,7 +118,7 @@ spotless {
 test {
     useJUnitPlatform()
     testLogging {
-        events "PASSED", "FAILED", "SKIPPED"
+        events "FAILED"
         showStandardStreams = true
         exceptionFormat "full"
     }