API 34: Change Kotlin JVM Target default.

The new default value is null. When null, it will by default
to the Java Target compatibility. Updating AndroidJavaTargetCompatibility
will also influence the Kotlin JVM target, unless if AndroidKotlinJVMTarget
is also explicitly defined.

framework/cdv-gradle-config-defaults.json

@@ -15,5 +15,5 @@
     "PACKAGE_NAMESPACE": "io.cordova.helloCordova",
     "JAVA_SOURCE_COMPATIBILITY": 8,
     "JAVA_TARGET_COMPATIBILITY": 8,
-    "KOTLIN_JVM_TARGET": "1.8"
+    "KOTLIN_JVM_TARGET": null
 }

templates/project/app/build.gradle

@@ -257,6 +257,34 @@ android {
     }
 
     if (cordovaConfig.IS_GRADLE_PLUGIN_KOTLIN_ENABLED) {
+        if (cordovaConfig.KOTLIN_JVM_TARGET == null) {
+            // If the value is null, fallback to JAVA_TARGET_COMPATIBILITY,
+            // as they generally should be equal
+            def javaTarget = JavaLanguageVersion.of(cordovaConfig.JAVA_TARGET_COMPATIBILITY)
+            println "FALLBACK: " + javaTarget
+
+            // check if javaTarget is <= 8; if so, we need to prefix it with "1."
+            // Starting with 9 and later, the value can be used as is.
+            if (javaTarget.compareTo(JavaLanguageVersion.of(8)) <= 0) {
+                println "PREFIXING 1."
+                javaTarget = "1." + javaTarget
+            }
+
+            cordovaConfig.KOTLIN_JVM_TARGET = javaTarget
+        }
+
+        // Similar to above, check if kotlin target is <= 8, if so prefix it.
+        // This allows the user to use consistent set of values in config.xml
+        // Rather than having to be aware whether the "1."" prefix is needed.
+        // This check is only done if the value isn't already prefixed with 1.
+        if (
+            !cordovaConfig.KOTLIN_JVM_TARGET.startsWith("1.") &&
+            JavaLanguageVersion.of(cordovaConfig.KOTLIN_JVM_TARGET).compareTo(JavaLanguageVersion.of(8)) <= 0
+        ) {
+            cordovaConfig.KOTLIN_JVM_TARGET = "1." + cordovaConfig.KOTLIN_JVM_TARGET
+        }
+
+        println "KOTLINJVMTARGET: " + cordovaConfig.KOTLIN_JVM_TARGET
         kotlinOptions {
             jvmTarget = cordovaConfig.KOTLIN_JVM_TARGET
         }