From 07c11c03cc7f6d182eab9b50e2f3908ee397f70f Mon Sep 17 00:00:00 2001
From: Dave Methvin <dave.methvin@gmail.com>
Date: Tue, 10 May 2016 21:50:00 -0400
Subject: [PATCH] Deferred: Give better stack diagnostics on exceptions

Ref gh-2736

The exception stack has the name of the immediately outer function where the
exception occurred, which can be very handy for tracing errors. Since we already
have the exception object we might as well use it.
---
 src/deferred/exceptionHook.js |  2 +-
 test/unit/deferred.js         | 25 ++++++++++++++++---------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/deferred/exceptionHook.js b/src/deferred/exceptionHook.js
index 7d4a296f4..6dbdc8520 100644
--- a/src/deferred/exceptionHook.js
+++ b/src/deferred/exceptionHook.js
@@ -14,7 +14,7 @@ jQuery.Deferred.exceptionHook = function( error, stack ) {
 	// Support: IE 8 - 9 only
 	// Console exists when dev tools are open, which can happen at any time
 	if ( window.console && window.console.warn && error && rerrorNames.test( error.name ) ) {
-		window.console.warn( "jQuery.Deferred exception: " + error.message, stack );
+		window.console.warn( "jQuery.Deferred exception: " + error.message, error.stack, stack );
 	}
 };
 
diff --git a/test/unit/deferred.js b/test/unit/deferred.js
index 906555319..d8ea1918f 100644
--- a/test/unit/deferred.js
+++ b/test/unit/deferred.js
@@ -542,28 +542,30 @@ QUnit.test( "jQuery.Deferred.then - spec compatibility", function( assert ) {
 	} catch ( _ ) {}
 } );
 
+// Test fails in IE9 but is skipped there because console is not active
 QUnit[ window.console ? "test" : "skip" ]( "jQuery.Deferred.exceptionHook", function( assert ) {
 
-	assert.expect( 1 );
+	assert.expect( 2 );
 
 	var done = assert.async(),
 		defer = jQuery.Deferred(),
 		oldWarn = window.console.warn;
 
-	window.console.warn = function( msg ) {
+	window.console.warn = function() {
 
 		// Support: Chrome <=41 only
 		// Some Chrome versions newer than 30 but older than 42 display the "undefined is
 		// not a function" error, not mentioning the function name. This has been fixed
 		// in Chrome 42. Relax this test there.
 		// This affects our Android 5.0 & Yandex.Browser testing.
-		var oldChromium = false;
+		var msg = Array.prototype.join.call( arguments, " " ),
+			oldChromium = false;
 		if ( /chrome/i.test( navigator.userAgent ) ) {
 			oldChromium = parseInt(
 					navigator.userAgent.match( /chrome\/(\d+)/i )[ 1 ], 10 ) < 42;
 		}
 		if ( oldChromium ) {
-			assert.ok( /(?:barf|undefined)/.test( msg ), "Message: " + msg );
+			assert.ok( /(?:barf|undefined)/.test( msg ), "Message (weak assertion): " + msg );
 		} else {
 			assert.ok( /barf/.test( msg ), "Message: " + msg );
 		}
@@ -580,7 +582,9 @@ QUnit[ window.console ? "test" : "skip" ]( "jQuery.Deferred.exceptionHook", func
 			// Should NOT get an error
 			throw new Error( "Make me a sandwich" );
 		} ).then( null, jQuery.noop )
-	).then( function( ) {
+	).then( function barf( ) {
+		jQuery.thisDiesToo();
+	} ).then( null, function( ) {
 		window.console.warn = oldWarn;
 		done();
 	} );
@@ -588,6 +592,7 @@ QUnit[ window.console ? "test" : "skip" ]( "jQuery.Deferred.exceptionHook", func
 	defer.resolve();
 } );
 
+// Test fails in IE9 but is skipped there because console is not active
 QUnit[ window.console ? "test" : "skip" ]( "jQuery.Deferred.exceptionHook with stack hooks", function( assert ) {
 
 	assert.expect( 2 );
@@ -605,24 +610,26 @@ QUnit[ window.console ? "test" : "skip" ]( "jQuery.Deferred.exceptionHook with s
 		return "NO STACK FOR YOU";
 	};
 
-	window.console.warn = function( msg, stack ) {
+	window.console.warn = function() {
 
 		// Support: Chrome <=41 only
 		// Some Chrome versions newer than 30 but older than 42 display the "undefined is
 		// not a function" error, not mentioning the function name. This has been fixed
 		// in Chrome 42. Relax this test there.
 		// This affects our Android 5.0 & Yandex.Browser testing.
-		var oldChromium = false;
+		var msg = Array.prototype.join.call( arguments, " " ),
+			oldChromium = false;
 		if ( /chrome/i.test( navigator.userAgent ) ) {
 			oldChromium = parseInt(
 					navigator.userAgent.match( /chrome\/(\d+)/i )[ 1 ], 10 ) < 42;
 		}
 		if ( oldChromium ) {
-			assert.ok( /(?:cough_up_hairball|undefined)/.test( msg ), "Function mentioned: " + msg );
+			assert.ok( /(?:cough_up_hairball|undefined)/.test( msg ),
+				"Function mentioned (weak assertion): " + msg );
 		} else {
 			assert.ok( /cough_up_hairball/.test( msg ), "Function mentioned: " + msg );
 		}
-		assert.ok( /NO STACK FOR YOU/.test( stack ), "Stack trace included: " + stack );
+		assert.ok( /NO STACK FOR YOU/.test( msg ), "Stack trace included: " + msg );
 	};
 	defer.then( function() {
 		jQuery.cough_up_hairball();
-- 
2.39.5