From a7d032b7071d7477a624836ec36cf23603774c3f Mon Sep 17 00:00:00 2001
From: Marc Horowitz <mhorowitz@fb.com>
Date: Wed, 6 Jul 2016 16:01:17 -0700
Subject: [PATCH] Display JS exceptions and stacks in a red box

Reviewed By: astreet

Differential Revision: D3510875

fbshipit-source-id: a7042434b68cb849f5b0c4ef782befff6a27ef5c
---
 .../devsupport/DevSupportManagerImpl.java     |  9 ++++-
 .../react/devsupport/JSException.java         | 37 +++++++++++++++++++
 .../jni/xreact/jni/JMessageQueueThread.cpp    | 30 ++++++++++++++-
 3 files changed, 73 insertions(+), 3 deletions(-)
 create mode 100644 ReactAndroid/src/main/java/com/facebook/react/devsupport/JSException.java

diff --git a/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevSupportManagerImpl.java b/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevSupportManagerImpl.java
index dd823f84a..8bb5423e9 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevSupportManagerImpl.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevSupportManagerImpl.java
@@ -79,6 +79,7 @@ import com.facebook.react.modules.debug.DeveloperSettings;
 public class DevSupportManagerImpl implements DevSupportManager {
 
   private static final int JAVA_ERROR_COOKIE = -1;
+  private static final int JSEXCEPTION_ERROR_COOKIE = -1;
   private static final String JS_BUNDLE_FILE_NAME = "ReactNativeDevBundle.js";
   private static enum ErrorType {
     JS,
@@ -194,7 +195,13 @@ public class DevSupportManagerImpl implements DevSupportManager {
   public void handleException(Exception e) {
     if (mIsDevSupportEnabled) {
       FLog.e(ReactConstants.TAG, "Exception in native call from JS", e);
-      showNewJavaError(e.getMessage(), e);
+      if (e instanceof JSException) {
+        // TODO #11638796: convert the stack into something useful
+        showNewError(e.getMessage() + "\n\n" + ((JSException) e).getStack(), new StackFrame[] {},
+                     JSEXCEPTION_ERROR_COOKIE, ErrorType.JS);
+      } else {
+        showNewJavaError(e.getMessage(), e);
+      }
     } else {
       mDefaultNativeModuleCallExceptionHandler.handleException(e);
     }
diff --git a/ReactAndroid/src/main/java/com/facebook/react/devsupport/JSException.java b/ReactAndroid/src/main/java/com/facebook/react/devsupport/JSException.java
new file mode 100644
index 000000000..ca83f57bb
--- /dev/null
+++ b/ReactAndroid/src/main/java/com/facebook/react/devsupport/JSException.java
@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.devsupport;
+
+import com.facebook.proguard.annotations.DoNotStrip;
+
+/**
+ * This represents an error evaluating JavaScript.  It includes the usual
+ * message, and the raw JS stack where the error occurred (which may be empty).
+ */
+
+@DoNotStrip
+public class JSException extends Exception {
+  private final String mStack;
+
+  @DoNotStrip
+  public JSException(String message, String stack, Throwable cause) {
+    super(message, cause);
+    mStack = stack;
+  }
+
+  public JSException(String message, String stack) {
+    super(message);
+    mStack = stack;
+  }
+
+  public String getStack() {
+    return mStack;
+  }
+}
diff --git a/ReactAndroid/src/main/jni/xreact/jni/JMessageQueueThread.cpp b/ReactAndroid/src/main/jni/xreact/jni/JMessageQueueThread.cpp
index 6cba3235c..2510c2841 100644
--- a/ReactAndroid/src/main/jni/xreact/jni/JMessageQueueThread.cpp
+++ b/ReactAndroid/src/main/jni/xreact/jni/JMessageQueueThread.cpp
@@ -9,11 +9,37 @@
 #include <folly/Memory.h>
 #include <fb/fbjni.h>
 
+#include <cxxreact/JSCHelpers.h>
+
 #include "JNativeRunnable.h"
 
 namespace facebook {
 namespace react {
 
+namespace {
+
+struct JavaJSException : jni::JavaClass<JavaJSException, JThrowable> {
+  static constexpr auto kJavaDescriptor = "Lcom/facebook/react/devsupport/JSException;";
+
+  static local_ref<JavaJSException> create(const char* message, const char* stack,
+                                           const std::exception& ex) {
+    local_ref<jthrowable> cause = jni::JCppException::create(ex);
+    return newInstance(make_jstring(message), make_jstring(stack), cause.get());
+  }
+};
+
+std::function<void()> wrapRunnable(std::function<void()>&& runnable) {
+  return [runnable=std::move(runnable)] {
+    try {
+      runnable();
+    } catch (const JSException& ex) {
+      throwNewJavaException(JavaJSException::create(ex.what(), ex.getStack().c_str(), ex).get());
+    }
+  };
+}
+
+}
+
 JMessageQueueThread::JMessageQueueThread(alias_ref<JavaMessageQueueThread::javaobject> jobj) :
     m_jobj(make_global(jobj)) {
 }
@@ -21,7 +47,7 @@ JMessageQueueThread::JMessageQueueThread(alias_ref<JavaMessageQueueThread::javao
 void JMessageQueueThread::runOnQueue(std::function<void()>&& runnable) {
   static auto method = JavaMessageQueueThread::javaClassStatic()->
     getMethod<void(Runnable::javaobject)>("runOnQueue");
-  method(m_jobj, JNativeRunnable::newObjectCxxArgs(runnable).get());
+  method(m_jobj, JNativeRunnable::newObjectCxxArgs(wrapRunnable(std::move(runnable))).get());
 }
 
 void JMessageQueueThread::runOnQueueSync(std::function<void()>&& runnable) {
@@ -29,7 +55,7 @@ void JMessageQueueThread::runOnQueueSync(std::function<void()>&& runnable) {
     getMethod<jboolean()>("isOnThread");
 
   if (jIsOnThread(m_jobj)) {
-    runnable();
+    wrapRunnable(std::move(runnable))();
   } else {
     std::mutex signalMutex;
     std::condition_variable signalCv;