Deferred: Warn on exceptions that are likely programming errors

Fixes gh-2736
Closes gh-2737

1 files changed, 19 insertions, 0 deletions

diff --git a/src/deferred/exceptionHook.js b/src/deferred/exceptionHook.js
new file mode 100644
index 000000000..b9955063a
--- /dev/null
+++ b/src/deferred/exceptionHook.js
@@ -0,0 +1,19 @@
+define( [
+	"../core",
+	"../deferred"
+], function( jQuery ) {
+
+// These usually indicate a programmer mistake during development,
+// warn about them ASAP rather than swallowing them by default.
+var rerrorNames = /^(Eval|Internal|Range|Reference|Syntax|Type|URI)Error$/;
+
+jQuery.Deferred.exceptionHook = function( error, stack ) {
+
+	// Support: IE9
+	// 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 );
+	}
+};
+
+} );