Expose the API to pass flags to KAPT.

Author: vRallev

core/build.gradle

@@ -36,7 +36,7 @@ dependencies {
     // The Kotlin compiler should be near the end of the list because its .jar file includes
     // an obsolete version of Guava
     api "org.jetbrains.kotlin:kotlin-compiler-embeddable:$embedded_kotlin_version"
-    implementation "org.jetbrains.kotlin:kotlin-annotation-processing-embeddable:$embedded_kotlin_version"
+    api "org.jetbrains.kotlin:kotlin-annotation-processing-embeddable:$embedded_kotlin_version"
 }
 
 compileKotlin {

core/src/main/kotlin/com/tschuchort/compiletesting/KotlinCompilation.kt

@@ -52,6 +52,9 @@ class KotlinCompilation : AbstractKotlinCompilation<K2JVMCompilerArguments>() {
 	/** Arbitrary arguments to be passed to kapt */
 	var kaptArgs: MutableMap<OptionName, OptionValue> = mutableMapOf()
 
+	/** Arbitrary flags to be passed to kapt */
+	var kaptFlags: MutableSet<KaptFlag> = mutableSetOf()
+
 	/** Annotation processors to be passed to kapt */
 	var annotationProcessors: List<Processor> = emptyList()
 
@@ -370,8 +373,13 @@ class KotlinCompilation : AbstractKotlinCompilation<K2JVMCompilerArguments>() {
 
 			it.mode = AptMode.STUBS_AND_APT
 
-			if (verbose)
-				it.flags.addAll(KaptFlag.MAP_DIAGNOSTIC_LOCATIONS, KaptFlag.VERBOSE)
+			it.flags.apply {
+				addAll(kaptFlags)
+
+				if (verbose) {
+					addAll(KaptFlag.MAP_DIAGNOSTIC_LOCATIONS, KaptFlag.VERBOSE)
+				}
+			}
 		}
 
 		val compilerMessageCollector = PrintingMessageCollector(