Fix infinite recursive loop in Kotlin generics

Fixes #9

Author: vRallev

demo/src/main/kotlin/com/evernote/android/state/test/TestKotlinComparable.kt

@@ -0,0 +1,51 @@
+@file:Suppress("unused")
+
+package com.evernote.android.state.test
+
+import com.evernote.android.state.State
+import java.io.Serializable
+import java.util.*
+
+/**
+ * Copyright 2017 Evernote Corporation. All rights reserved.
+ *
+ * Created by rwondratschek on 3/1/17.
+ */
+class MyComparator : Comparator<MyComparable>, Serializable {
+    override fun compare(o1: MyComparable, o2: MyComparable): Int = 0
+}
+
+class MyComparable : Comparable<MyComparable>, Serializable {
+    override fun compareTo(other: MyComparable): Int = 0
+}
+
+interface MyInterface<T : MyInterface<T>> {
+    fun doSomething(other: T)
+}
+
+class MyInterfaceImpl : MyInterface<MyInterfaceImpl>, Serializable {
+    override fun doSomething(other: MyInterfaceImpl) {}
+}
+
+interface MySerializableInterface<T : MySerializableInterface<T>> : Serializable {
+    fun doSomething(other: T)
+}
+
+class MySerializableImpl : MySerializableInterface<MySerializableImpl> {
+    override fun doSomething(other: MySerializableImpl) {}
+}
+
+class TestKotlinComparable {
+
+    @State
+    var comparator: MyComparator? = null
+
+    @State
+    var comparable: MyComparable? = null
+
+    @State
+    var myInterface: MyInterfaceImpl? = null
+
+    @State
+    var mySerializableInterface: MySerializableImpl? = null
+}

processor/src/main/java/com/evernote/android/state/StateProcessor.java

@@ -65,7 +65,6 @@
 /**
  * @author rwondratschek
  */
-@SuppressWarnings("unused")
 @AutoService(Processor.class)
 public class StateProcessor extends AbstractProcessor {
 
@@ -116,9 +115,6 @@ public int compare(Element o1, Element o2) {
     private static final String OBJECT_CLASS_NAME = Object.class.getName();
     private static final String PARCELABLE_CLASS_NAME = Parcelable.class.getName();
     private static final String SERIALIZABLE_CLASS_NAME = Serializable.class.getName();
-    private static final String ARRAY_LIST_CLASS_NAME = ArrayList.class.getName();
-    private static final String SPARSE_ARRAY_CLASS_NAME = SparseArray.class.getName();
-    private static final String ENUM_CLASS_NAME = Enum.class.getName();
 
     private static final Set<String> IGNORED_TYPE_DECLARATIONS = Collections.unmodifiableSet(new HashSet<String>() {{
         add(Bundle.class.getName());
@@ -731,7 +727,7 @@ private TypeMirror getInsertedType(TypeMirror fieldType, boolean checkIgnoredTyp
         }
 
         TypeElement classElement = mElementUtils.getTypeElement(fieldType.toString());
-        if (classElement == null) {
+        if (classElement == null || OBJECT_CLASS_NAME.equals(classElement.toString())) {
             return null;
         }
 
@@ -749,11 +745,10 @@ private TypeMirror getInsertedType(TypeMirror fieldType, boolean checkIgnoredTyp
                 if (SERIALIZABLE_CLASS_NAME.equals(superTypeString)) {
                     return fieldType;
                 }
-                if (superTypeString.startsWith(ENUM_CLASS_NAME)) {
-                    // Necessary for Kotlin enums, otherwise this ends in an endless loop, e.g. java.lang.Enum<com.world.MyEnum>
-                    return fieldType;
-                }
-                TypeMirror result = getInsertedType(superType, checkIgnoredTypes);
+            }
+
+            for (TypeMirror superType : typeMirrors) {
+                TypeMirror result = getInsertedType(eraseGenericIfNecessary(superType), checkIgnoredTypes);
                 if (result != null) {
                     // always return the passed in type and not any super type
                     return fieldType;