Merge pull request #389 from cujojs/prevent-console-removal

Prevent minifiers from silencing unhandled rejections

Author: briancavalier

lib/decorators/unhandledRejection.js

@@ -10,15 +10,20 @@ define(function(require) {
 	return function unhandledRejection(Promise) {
 		var logError = noop;
 		var logInfo = noop;
+		var localConsole;
 
 		if(typeof console !== 'undefined') {
-			logError = typeof console.error !== 'undefined'
-				? function (e) { console.error(e); }
-				: function (e) { console.log(e); };
-
-			logInfo = typeof console.info !== 'undefined'
-				? function (e) { console.info(e); }
-				: function (e) { console.log(e); };
+			// Alias console to prevent things like uglify's drop_console option from
+			// removing console.log/error. Unhandled rejections fall into the same
+			// category as uncaught exceptions, and build tools shouldn't silence them.
+			localConsole = console;
+			logError = typeof localConsole.error !== 'undefined'
+				? function (e) { localConsole.error(e); }
+				: function (e) { localConsole.log(e); };
+
+			logInfo = typeof localConsole.info !== 'undefined'
+				? function (e) { localConsole.info(e); }
+				: function (e) { localConsole.log(e); };
 		}
 
 		Promise.onPotentiallyUnhandledRejection = function(rejection) {

monitor/ConsoleReporter.js

@@ -46,37 +46,41 @@ define(function(require) {
 		if(typeof console === 'undefined') {
 			log = warn = consoleNotAvailable;
 		} else {
-			if(typeof console.error === 'function'
-				&& typeof console.dir === 'function') {
+			// Alias console to prevent things like uglify's drop_console option from
+			// removing console.log/error. Unhandled rejections fall into the same
+			// category as uncaught exceptions, and build tools shouldn't silence them.
+			var localConsole = console;
+			if(typeof localConsole.error === 'function'
+				&& typeof localConsole.dir === 'function') {
 				warn = function(s) {
-					console.error(s);
+					localConsole.error(s);
 				};
 
 				log = function(s) {
-					console.log(s);
+					localConsole.log(s);
 				};
 
-				if(typeof console.groupCollapsed === 'function') {
+				if(typeof localConsole.groupCollapsed === 'function') {
 					groupStart = function(s) {
-						console.groupCollapsed(s);
+						localConsole.groupCollapsed(s);
 					};
 					groupEnd = function() {
-						console.groupEnd();
+						localConsole.groupEnd();
 					};
 				}
 			} else {
 				// IE8 has console.log and JSON, so we can make a
 				// reasonably useful warn() from those.
 				// Credit to webpro (https://github.com/webpro) for this idea
-				if (typeof console.log ==='function'
+				if (typeof localConsole.log ==='function'
 					&& typeof JSON !== 'undefined') {
 					log = warn = function (x) {
 						if(typeof x !== 'string') {
 							try {
 								x = JSON.stringify(x);
 							} catch(e) {}
 						}
-						console.log(x);
+						localConsole.log(x);
 					};
 				}
 			}