Fix Kotlin Object issue (#1562)

Author: vmutafov

test-app/app/src/main/assets/app/tests/kotlin/objects/testObjectsSupport.js

@@ -2,6 +2,12 @@ describe("Tests Kotlin objects support", function () {
     it("Test Kotlin object instances should be the same reference", function () {
     	var kotlinClass = com.tns.tests.kotlin.objects.KotlinSingleton.INSTANCE;
     	var kotlinClass2 = com.tns.tests.kotlin.objects.KotlinSingleton.INSTANCE;
+
+    	expect(kotlinClass).not.toBe(null);
+    	expect(kotlinClass).not.toBe(undefined);
+    	expect(kotlinClass2).not.toBe(null);
+    	expect(kotlinClass2).not.toBe(undefined);
+
     	expect(com.tns.EqualityComparator.areReferencesEqual(kotlinClass, kotlinClass2)).toBe(true);
     });
 });

test-app/build-tools/android-metadata-generator/src/src/com/telerik/metadata/parsing/kotlin/classes/KotlinClassDescriptor.kt

@@ -2,13 +2,15 @@ package com.telerik.metadata.parsing.kotlin.classes
 
 import com.telerik.metadata.ClassRepo
 import com.telerik.metadata.ClassUtil
+import com.telerik.metadata.ClassUtil.getCanonicalName
 import com.telerik.metadata.parsing.NativeFieldDescriptor
 import com.telerik.metadata.parsing.NativeMethodDescriptor
 import com.telerik.metadata.parsing.NativePropertyDescriptor
 import com.telerik.metadata.parsing.bytecode.classes.NativeClassBytecodeDescriptor
 import com.telerik.metadata.parsing.kotlin.fields.KotlinCompanionFieldDescriptor
 import com.telerik.metadata.parsing.kotlin.fields.KotlinEnumFieldDescriptor
 import com.telerik.metadata.parsing.kotlin.fields.KotlinJvmFieldDescriptor
+import com.telerik.metadata.parsing.kotlin.fields.KotlinObjectInstanceFieldDescriptor
 import com.telerik.metadata.parsing.kotlin.metadata.MetadataAnnotation
 import com.telerik.metadata.parsing.kotlin.metadata.bytecode.BytecodeClassMetadataParser
 import com.telerik.metadata.parsing.kotlin.methods.KotlinMethodDescriptor
@@ -49,7 +51,12 @@ class KotlinClassDescriptor(nativeClass: JavaClass, private val metadataAnnotati
                 fields.add(possibleCompanionField.get())
             }
 
-            if(metaClass.enumEntries.isNotEmpty()){
+            val possibleObjectInstanceField = getObjectFieldIfAny(nativeClass)
+            if(possibleObjectInstanceField.isPresent){
+                fields.add(possibleObjectInstanceField.get())
+            }
+
+            if (metaClass.enumEntries.isNotEmpty()) {
                 val enumFields = getEnumEntriesAsFields(nativeClass, metaClass.enumEntries)
                 fields.addAll(enumFields)
             }
@@ -113,6 +120,21 @@ class KotlinClassDescriptor(nativeClass: JavaClass, private val metadataAnnotati
         return Optional.empty()
     }
 
+    private fun getObjectFieldIfAny(nativeClass: JavaClass): Optional<KotlinObjectInstanceFieldDescriptor> {
+        return nativeClass
+                .fields
+                .singleOrNull { field ->
+                    field.name == "INSTANCE" && getCanonicalName(field.type.signature) == nativeClass.className
+                }.run {
+                    if (this != null) {
+                        val objectInstanceField = KotlinObjectInstanceFieldDescriptor(this@run, this@KotlinClassDescriptor)
+                        Optional.of(objectInstanceField)
+                    } else {
+                        Optional.empty()
+                    }
+                }
+    }
+
     private fun getEnumEntriesAsFields(nativeClass: JavaClass, metadataEnumEntries: Collection<String>): Collection<KotlinEnumFieldDescriptor> {
         val bytecodeFields = nativeClass.fields
 

test-app/build-tools/android-metadata-generator/src/src/com/telerik/metadata/parsing/kotlin/fields/KotlinObjectInstanceFieldDescriptor.kt

@@ -0,0 +1,11 @@
+package com.telerik.metadata.parsing.kotlin.fields
+
+import com.telerik.metadata.parsing.bytecode.fields.NativeFieldBytecodeDescriptor
+import com.telerik.metadata.parsing.kotlin.classes.KotlinClassDescriptor
+import org.apache.bcel.classfile.Field
+
+class KotlinObjectInstanceFieldDescriptor(field: Field, companion: KotlinClassDescriptor) : NativeFieldBytecodeDescriptor(field) {
+    override val isPublic = companion.isPublic
+    override val isInternal = companion.isInternal
+    override val isProtected = companion.isProtected
+}