refactor: Rewrite JSBundleLoader from Java to Kotlin

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

@@ -0,0 +1,103 @@
+/*
+ * 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 android.content.Context
+import com.facebook.react.common.DebugServerException
+
+/** A class that stores JS bundle information and allows a [JSBundleLoaderDelegate]. */
+public abstract class JSBundleLoader {
+
+  /** Loads the script, returning the URL of the source it loaded. */
+  public abstract fun loadScript(delegate: JSBundleLoaderDelegate): String
+
+  public companion object {
+    /**
+     * This loader is recommended one for release version of your app. In that case local JS
+     * executor should be used. JS bundle will be read from assets in native code to save on passing
+     * large strings from java to native memory.
+     */
+    @JvmStatic
+    public fun createAssetLoader(
+        context: Context,
+        assetUrl: String,
+        loadSynchronously: Boolean
+    ): JSBundleLoader {
+      return object : JSBundleLoader() {
+        override fun loadScript(delegate: JSBundleLoaderDelegate): String {
+          delegate.loadScriptFromAssets(context.assets, assetUrl, loadSynchronously)
+          return assetUrl
+        }
+      }
+    }
+
+    /**
+     * This loader loads bundle from file system. The bundle will be read in native code to save on
+     * passing large strings from java to native memory.
+     */
+    @JvmStatic
+    public fun createFileLoader(fileName: String): JSBundleLoader =
+        createFileLoader(fileName, fileName, false)
+
+    @JvmStatic
+    public fun createFileLoader(
+        fileName: String,
+        assetUrl: String,
+        loadSynchronously: Boolean
+    ): JSBundleLoader {
+      return object : JSBundleLoader() {
+        override fun loadScript(delegate: JSBundleLoaderDelegate): String {
+          delegate.loadScriptFromFile(fileName, assetUrl, loadSynchronously)
+          return fileName
+        }
+      }
+    }
+
+    /**
+     * This loader is used when bundle gets reloaded from dev server. In that case loader expect JS
+     * bundle to be prefetched and stored in local file. We do that to avoid passing large strings
+     * between java and native code and avoid allocating memory in java to fit whole JS bundle in
+     * it. Providing correct [sourceURL] of downloaded bundle is required for JS stacktraces to work
+     * correctly and allows for source maps to correctly symbolize those.
+     */
+    @JvmStatic
+    public fun createCachedBundleFromNetworkLoader(
+        sourceURL: String,
+        cachedFileLocation: String
+    ): JSBundleLoader {
+      return object : JSBundleLoader() {
+        override fun loadScript(delegate: JSBundleLoaderDelegate): String {
+          return try {
+            delegate.loadScriptFromFile(cachedFileLocation, sourceURL, false)
+            sourceURL
+          } catch (e: Exception) {
+            throw DebugServerException.makeGeneric(sourceURL, e.message ?: "", e)
+          }
+        }
+      }
+    }
+
+    /** Same as [createCachedBundleFromNetworkLoader], but for split bundles in development. */
+    @JvmStatic
+    public fun createCachedSplitBundleFromNetworkLoader(
+        sourceURL: String,
+        cachedFileLocation: String
+    ): JSBundleLoader {
+      return object : JSBundleLoader() {
+        override fun loadScript(delegate: JSBundleLoaderDelegate): String {
+          return try {
+            delegate.loadSplitBundleFromFile(cachedFileLocation, sourceURL)
+            sourceURL
+          } catch (e: Exception) {
+            throw DebugServerException.makeGeneric(sourceURL, e.message ?: "", e)
+          }
+        }
+      }
+    }
+  }
+}