📝 Farewell iostream

README.md

@@ -7,6 +7,7 @@ This is a part of [Node3D](https://github.com/node-3d) project.
 
 Helpers for Node.js addons and dependency packages:
 
+* `consoleLog()` C++ implementation.
 * `EventEmitter` C++ implementation.
 * C++ macros and shortcuts.
 * Crossplatform commands for GYP: `cp`, `rm`, `mkdir`.
@@ -36,6 +37,8 @@ Useful links: [V8 Ref](https://v8docs.nodesource.com/node-0.8/d2/dc3/namespacev8
 
 [Class EventEmitter](#class-eventemitter)
 
+[Function consoleLog](#function-consolelog)
+
 ---
 
 
@@ -668,7 +671,7 @@ For Windows the `/y` flag was embedded.
 ---
 
 
-## class EventEmitter
+## Class EventEmitter
 
 A C++ implementation of [Events API](https://nodejs.org/api/events.html).
 
@@ -750,3 +753,23 @@ void Example::init(Handle<Object> target) {
 ```
 
 </details>
+
+---
+
+
+## Function consoleLog
+
+In C++ addons, the use of **iostream** is discouraged because **Node.js** has its own
+perspective on **stdout** behavior.
+At first it may look as if `cout << "msg" << endl;` works nice, but it doesn't.
+After a while, it just ceases on a midword, and you end up thinking something has
+broken really hard in your addon.
+
+To overcome this, we can use some V8 `eval` magic to make a real `console.log`
+call from C++ land. And this is where `consoleLog` comes into play.
+
+* `inline void consoleLog(int argc, V8_VAR_VAL *argv)` - a generic logger,
+receives any set of arguments.
+
+* `inline void consoleLog(const std::string &message)` - an alias to log a single
+string.

include/addon-tools.hpp

@@ -287,4 +287,24 @@ inline void *getImageData(v8::Local<v8::Value> arg) {
 }
 
 
+inline void consoleLog(int argc, V8_VAR_VAL *argv) {
+	
+	V8_VAR_STR code = JS_STR("((...args) => console.log(...args))");
+	
+	V8_VAR_FUNC log = V8_VAR_FUNC::Cast(v8::Script::Compile(code)->Run());
+	Nan::Callback logCb(log);
+	Nan::AsyncResource async("consoleLog()");
+	logCb.Call(argc, argv, &async);
+	
+}
+
+
+inline void consoleLog(const std::string &message) {
+	
+	V8_VAR_VAL arg = JS_STR(message);
+	consoleLog(1, &arg);
+	
+}
+
+
 #endif // _ADDON_TOOLS_HPP_

include/event-emitter.hpp

@@ -7,7 +7,6 @@
 #include <string>
 #include <map>
 #include <deque>
-#include <iostream> // -> std::cout << "..." << std::endl;
 
 
 #define THIS_EVENT_EMITTER                                                    \
@@ -308,6 +307,33 @@ private:
 		
 	}
 	
+	static inline void _reportListeners(
+		const std::string &name,
+		int numListeners,
+		int maxListeners
+	) {
+		
+		std::string msg = "EventEmitter Warning: too many listeners (";
+		msg += std::to_string(numListeners);
+		msg += " > ";
+		msg += std::to_string(maxListeners);
+		msg += ") on '";
+		msg += name;
+		msg += "' event, possible memory leak.\n";
+		
+		// Some JS magic to retrieve the call stack
+		V8_VAR_STR code = JS_STR(
+			"(new Error()).stack.split('\\n').slice(2).join('\\n')"
+		);
+		V8_VAR_STR stack = V8_VAR_STR::Cast(
+			v8::Script::Compile(code)->Run()
+		);
+		Nan::Utf8String stackStr(stack);
+		msg += *stackStr;
+		
+		consoleLog(msg);
+		
+	}
 	
 	static inline void _addListener(
 		const Nan::FunctionCallbackInfo<v8::Value> &info,
@@ -331,19 +357,7 @@ private:
 		
 		if (eventEmitter->_maxListeners > 0 && count > eventEmitter->_maxListeners) {
 			
-			std::cout << "EventEmitter Warning: too many listeners (";
+			_reportListeners(name, count, eventEmitter->_maxListeners);
-			std::cout << count << " > " << eventEmitter->_maxListeners << ") on '";
-			std::cout << name << "' event, possible memory leak." << std::endl;
-			
-			// Some JS magic to retrieve the call stack
-			V8_VAR_STR code = JS_STR(
-				"(new Error()).stack.split('\\n').slice(1).join('\\n')"
-			);
-			V8_VAR_STR stack = V8_VAR_STR::Cast(
-				v8::Script::Compile(code)->Run()
-			);
-			Nan::Utf8String stackStr(stack);
-			std::cout << *stackStr << std::endl;
 			
 		}
 		
@@ -393,19 +407,7 @@ private:
 		
 		if (eventEmitter->_maxListeners > 0 && count > eventEmitter->_maxListeners) {
 			
-			std::cout << "EventEmitter Warning: too many listeners (";
+			_reportListeners(name, count, eventEmitter->_maxListeners);
-			std::cout << count << " > " << eventEmitter->_maxListeners << ") on '";
-			std::cout << name << "' event, possible memory leak." << std::endl;
-			
-			// Some JS magic to retrieve the call stack
-			V8_VAR_STR code = JS_STR(
-				"(new Error()).stack.split('\\n').slice(1).join('\\n')"
-			);
-			V8_VAR_STR stack = V8_VAR_STR::Cast(
-				v8::Script::Compile(code)->Run()
-			);
-			Nan::Utf8String stackStr(stack);
-			std::cout << *stackStr << std::endl;
 			
 		}