Migrate NativeArray classes to Kotlin (facebook#44569)

Summary:
Pull Request resolved: facebook#44569

# Changelog:
[Internal] -

This converts the vertical of NativeArray/ReadableNativeArray/WritableNativeArray classes to Kotlin.

NOTE: the `getArray`, `getMap` and `getString` being annotated as `NonNull` in the Java code is a scam - there is no guarantee that native side will send non-null to the Java side, and in practice, indeed, in certain cases it doesn't. So I opted to make it nullable instead - this way it's at least explicit and is not a ticking bomb hidden to explode behind the false sense of security.

Differential Revision: https://internalfb.com/D57327835

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -1390,7 +1390,7 @@ public class com/facebook/react/bridge/ReadableNativeArray : com/facebook/react/
 	public fun getDouble (I)D
 	public fun getDynamic (I)Lcom/facebook/react/bridge/Dynamic;
 	public fun getInt (I)I
-	public static fun getJNIPassCounter ()I
+	public static final fun getJNIPassCounter ()I
 	public fun getLong (I)J
 	public synthetic fun getMap (I)Lcom/facebook/react/bridge/ReadableMap;
 	public fun getMap (I)Lcom/facebook/react/bridge/ReadableNativeMap;
@@ -1527,7 +1527,7 @@ public abstract interface class com/facebook/react/bridge/WritableMap : com/face
 	public abstract fun putString (Ljava/lang/String;Ljava/lang/String;)V
 }
 
-public class com/facebook/react/bridge/WritableNativeArray : com/facebook/react/bridge/ReadableNativeArray, com/facebook/react/bridge/WritableArray {
+public final class com/facebook/react/bridge/WritableNativeArray : com/facebook/react/bridge/ReadableNativeArray, com/facebook/react/bridge/WritableArray {
 	public fun <init> ()V
 	public fun pushArray (Lcom/facebook/react/bridge/ReadableArray;)V
 	public fun pushBoolean (Z)V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/NativeArray.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.bridge
+
+import com.facebook.jni.HybridData
+import com.facebook.proguard.annotations.DoNotStrip
+
+/** Base class for an array whose members are stored in native code (C++). */
+@DoNotStrip
+public abstract class NativeArray
+protected constructor(@field:DoNotStrip private val mHybridData: HybridData?) :
+    NativeArrayInterface {
+  external override fun toString(): String
+
+  private companion object {
+    init {
+      ReactBridge.staticInit()
+    }
+  }
+}

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReadableArray.kt

@@ -14,7 +14,7 @@ import java.util.ArrayList
  * to Kotlin.
  */
 public interface ReadableArray {
-  public fun getArray(index: Int): ReadableArray
+  public fun getArray(index: Int): ReadableArray?
 
   public fun getBoolean(index: Int): Boolean
 
@@ -26,7 +26,7 @@ public interface ReadableArray {
 
   public fun getLong(index: Int): Long
 
-  public fun getMap(index: Int): ReadableMap
+  public fun getMap(index: Int): ReadableMap?
 
   public fun getString(index: Int): String
 
@@ -36,5 +36,5 @@ public interface ReadableArray {
 
   public fun size(): Int
 
-  public fun toArrayList(): ArrayList<Any>
+  public fun toArrayList(): ArrayList<Any?>
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReadableNativeArray.kt

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.bridge
+
+import com.facebook.jni.HybridData
+import com.facebook.proguard.annotations.DoNotStripAny
+import java.util.Arrays
+
+/**
+ * Implementation of a NativeArray that allows read-only access to its members. This will generally
+ * be constructed and filled in native code so you shouldn't construct one yourself.
+ */
+@DoNotStripAny
+public open class ReadableNativeArray protected constructor(hybridData: HybridData?) :
+    NativeArray(hybridData), ReadableArray {
+
+  private val localArray: Array<Any?> by
+      lazy(LazyThreadSafetyMode.SYNCHRONIZED) {
+        jniPassCounter++
+        importArray()
+      }
+
+  private external fun importArray(): Array<Any?>
+
+  private val localTypeArray: Array<ReadableType> by
+      lazy(LazyThreadSafetyMode.SYNCHRONIZED) {
+        jniPassCounter++
+        importTypeArray()
+      }
+
+  private external fun importTypeArray(): Array<ReadableType>
+
+  override fun size(): Int = localArray.size
+
+  override fun isNull(index: Int): Boolean = localArray[index] == null
+
+  override fun getBoolean(index: Int): Boolean = localArray[index] as Boolean
+
+  override fun getDouble(index: Int): Double = localArray[index] as Double
+
+  override fun getInt(index: Int): Int = getDouble(index).toInt()
+
+  override fun getLong(index: Int): Long = localArray[index] as Long
+
+  override fun getString(index: Int): String = localArray[index] as String
+
+  override fun getArray(index: Int): ReadableNativeArray? =
+      localArray[index] as? ReadableNativeArray
+
+  override fun getMap(index: Int): ReadableNativeMap? = localArray[index] as? ReadableNativeMap
+
+  override fun getType(index: Int): ReadableType = localTypeArray[index]
+
+  override fun getDynamic(index: Int): Dynamic = DynamicFromArray.create(this, index)
+
+  override fun hashCode(): Int = localArray.hashCode()
+
+  override fun equals(other: Any?): Boolean =
+      if (other !is ReadableNativeArray) false else Arrays.deepEquals(localArray, other.localArray)
+
+  override fun toArrayList(): ArrayList<Any?> {
+    val arrayList = ArrayList<Any?>()
+    for (i in 0 until size()) {
+      when (getType(i)) {
+        ReadableType.Null -> arrayList.add(null)
+        ReadableType.Boolean -> arrayList.add(getBoolean(i))
+        ReadableType.Number -> arrayList.add(getDouble(i))
+        ReadableType.String -> arrayList.add(getString(i))
+        ReadableType.Map -> arrayList.add(getMap(i)?.toHashMap())
+        ReadableType.Array -> arrayList.add(getArray(i)?.toArrayList())
+        else -> throw IllegalArgumentException("Could not convert object at index: $i.")
+      }
+    }
+    return arrayList
+  }
+
+  private companion object {
+    init {
+      ReactBridge.staticInit()
+    }
+
+    private var jniPassCounter: Int = 0
+
+    @JvmStatic public fun getJNIPassCounter(): Int = jniPassCounter
+  }
+}