When debugger is attached continue to receive console messages

Summary:
I noticed an issue when the hermes debugger was attached. Console messages would no longer appear in the terminal. This is because the hermes inspector overrides the console object with its own to intercept messages and send them to the debug client.
With this change I made it so that messages are sent to the original console as well instead of completely replacing it.

Changelog:
[General][Fixed] - When Hermes debugger is enabled continue to send log messages to the console

Reviewed By: mhorowitz

Differential Revision: D21509895

fbshipit-source-id: 6d91c4b82682e404679533be14b3e5f12e687e79

Author: MartinSherburn

ReactCommon/hermes/inspector/Inspector.cpp

@@ -137,6 +137,7 @@ Inspector::~Inspector() {
 
 void Inspector::installConsoleFunction(
     jsi::Object &console,
+    std::shared_ptr<jsi::Object> &originalConsole,
     const std::string &name,
     const std::string &chromeTypeDefault = "") {
   jsi::Runtime &rt = adapter_->getRuntime();
@@ -150,11 +151,22 @@ void Inspector::installConsoleFunction(
           rt,
           nameID,
           1,
-          [weakInspector, chromeType](
+          [weakInspector, originalConsole, name, chromeType](
               jsi::Runtime &runtime,
               const jsi::Value &thisVal,
               const jsi::Value *args,
               size_t count) {
+            if (originalConsole) {
+              auto val = originalConsole->getProperty(runtime, name.c_str());
+              if (val.isObject()) {
+                auto obj = val.getObject(runtime);
+                if (obj.isFunction(runtime)) {
+                  auto func = obj.getFunction(runtime);
+                  func.call(runtime, args, count);
+                }
+              }
+            }
+
             if (auto inspector = weakInspector.lock()) {
               jsi::Array argsArray(runtime, count);
               for (size_t index = 0; index < count; ++index)
@@ -170,22 +182,28 @@ void Inspector::installConsoleFunction(
 void Inspector::installLogHandler() {
   jsi::Runtime &rt = adapter_->getRuntime();
   auto console = jsi::Object(rt);
-  installConsoleFunction(console, "assert");
-  installConsoleFunction(console, "clear");
-  installConsoleFunction(console, "debug");
-  installConsoleFunction(console, "dir");
-  installConsoleFunction(console, "dirxml");
-  installConsoleFunction(console, "error");
-  installConsoleFunction(console, "group", "startGroup");
-  installConsoleFunction(console, "groupCollapsed", "startGroupCollapsed");
-  installConsoleFunction(console, "groupEnd", "endGroup");
-  installConsoleFunction(console, "info");
-  installConsoleFunction(console, "log");
-  installConsoleFunction(console, "profile");
-  installConsoleFunction(console, "profileEnd");
-  installConsoleFunction(console, "table");
-  installConsoleFunction(console, "trace");
-  installConsoleFunction(console, "warn", "warning");
+  auto val = rt.global().getProperty(rt, "console");
+  std::shared_ptr<jsi::Object> originalConsole;
+  if (val.isObject()) {
+    originalConsole = std::make_shared<jsi::Object>(val.getObject(rt));
+  }
+  installConsoleFunction(console, originalConsole, "assert");
+  installConsoleFunction(console, originalConsole, "clear");
+  installConsoleFunction(console, originalConsole, "debug");
+  installConsoleFunction(console, originalConsole, "dir");
+  installConsoleFunction(console, originalConsole, "dirxml");
+  installConsoleFunction(console, originalConsole, "error");
+  installConsoleFunction(console, originalConsole, "group", "startGroup");
+  installConsoleFunction(
+      console, originalConsole, "groupCollapsed", "startGroupCollapsed");
+  installConsoleFunction(console, originalConsole, "groupEnd", "endGroup");
+  installConsoleFunction(console, originalConsole, "info");
+  installConsoleFunction(console, originalConsole, "log");
+  installConsoleFunction(console, originalConsole, "profile");
+  installConsoleFunction(console, originalConsole, "profileEnd");
+  installConsoleFunction(console, originalConsole, "table");
+  installConsoleFunction(console, originalConsole, "trace");
+  installConsoleFunction(console, originalConsole, "warn", "warning");
   rt.global().setProperty(rt, "console", console);
 }
 

ReactCommon/hermes/inspector/Inspector.h

@@ -292,6 +292,7 @@ class Inspector : public facebook::hermes::debugger::EventObserver,
 
   void installConsoleFunction(
       jsi::Object &console,
+      std::shared_ptr<jsi::Object> &originalConsole,
       const std::string &name,
       const std::string &chromeType);