Define getErrorHook, fix tests, update README

Author: mgol

README.md

@@ -1,6 +1,6 @@
 # jquery-deferred-reporter
 
-This jQuery plugin extends the `jQuery.Deferred` features added in version 3.0 to include a stack trace whenever a Deferred throws an exception. This makes it easier to find programming errors that occur inside Deferreds. 
+This jQuery plugin extends the `jQuery.Deferred` features added in version 3.0 to include an error captured before the async barrier whenever a Deferred throws an exception. This makes it easier to find programming errors that occur inside Deferreds. 
 
 ## Why does this plugin exist?
 
@@ -10,6 +10,4 @@ The native `Promise` object as implemented in the browser tracks Promise rejecti
 
 ## Why not just put this in jQuery?
 
- Since it has to save the stack trace regardless of whether an exception will happen or not, adding this plugin makes `jQuery.Deferred` [significantly slower](https://jsfiddle.net/h20r0e6z/5/), by roughly a factor of two.
- 
-
+ Since it has to save the error regardless of whether an exception will happen or not, adding this plugin makes `jQuery.Deferred` [significantly slower](https://jsfiddle.net/h20r0e6z/5/), by roughly a factor of two.

src/reporter.js

@@ -1,24 +1,30 @@
 ( function( factory ) {
+	"use strict";
 
-    if ( typeof define === "function" && define.amd ) {
-        define( "jquery-deferred-reporter", [ "jquery" ], factory );
-    } else if ( typeof module === "object" && module.exports ) {
-        module.exports = factory( require( "jquery" ) );
-    } else {
-        factory( jQuery );
-    }
 
-}( function( jQuery ) {
+	if ( typeof define === "function" && define.amd ) {
+		define( "jquery-deferred-reporter", [ "jquery" ], factory );
+	} else if ( typeof module === "object" && module.exports ) {
+		module.exports = factory( require( "jquery" ) );
+	} else {
+		factory( jQuery );
+	}
+
+} )( function( jQuery ) {
+	"use strict";
 
-	function getStackHook() {
+	function getErrorHook() {
 
-		// Throw an error so we can extract the stack from the Error
+		// Throw an error as IE doesn't capture `stack` of non-thrown ones.
 		try {
 			throw new Error( "Exception in jQuery.Deferred" );
 		} catch ( err ) {
-			return err.stack;
+			return err;
 		}
 	}
-	return jQuery.Deferred.getStackHook = getStackHook;
 
-} ) );
+	// Define both `jQuery.Deferred.getErrorHook` used in jQuery >=3.7.0
+	// and `jQuery.Deferred.getStackHook` used in jQuery <4.0.0.
+	return jQuery.Deferred.getStackHook = jQuery.Deferred.getErrorHook = getErrorHook;
+
+} );

test/test.js

@@ -1,58 +1,82 @@
+"use strict";
 
-QUnit.test( "Sanity", function( assert ) {
+// Polyfill `globalThis` for legacy browsers.
+if ( typeof globalThis === "undefined" ) {
+	window.globalThis = window;
+}
+
+QUnit.test( "Environment check", function( assert ) {
 	assert.expect( 1 );
-	assert.ok( Array.prototype.push, "Array.push()" );
+	assert.ok( Array.prototype.push, "Array#push()" );
 } );
 
-QUnit[ window.console ? "test" : "skip" ](
+QUnit[ globalThis.console ? "test" : "skip" ](
 "jQuery.Deferred.exceptionHook",
 function exceptionHookTest( assert ) {
 
 	assert.expect( 1 );
 
 	var done = assert.async(),
 		defer = jQuery.Deferred(),
-		oldWarn = window.console.warn;
+		oldWarn = globalThis.console.warn;
+
+	if ( jQuery.fn.jquery.indexOf( "3." ) === 0 ) {
+		globalThis.console.warn = function( msg ) {
+			assert.ok( /barf/.test( msg ), "Message: " + msg );
+		};
+	} else {
+		globalThis.console.warn = function( _intro, error ) {
+			assert.ok( /barf/.test( error.message + "\n" + error.stack ),
+				"Error mentions the method: " + error.message + "\n" + error.stack );
+		};
+	}
 
-	window.console.warn = function( msg ) {
-		assert.ok( /barf/.test( msg ), "Message: " + msg );
-	};
 	jQuery.when(
 		defer.then( function() {
+
 			// Should get an error
 			jQuery.barf();
 		} ).then( null, jQuery.noop ),
 		defer.then( function() {
+
 			// Should NOT get an error
 			throw new Error( "Make me a sandwich" );
 		} ).then( null, jQuery.noop )
 	).then( function( ) {
-		window.console.warn = oldWarn;
+		globalThis.console.warn = oldWarn;
 		done();
 	} );
 
 	defer.resolve();
 } );
 
-QUnit[ window.console ? "test" : "skip" ](
+QUnit[ globalThis.console ? "test" : "skip" ](
 "jQuery.Deferred.exceptionHook with stack hooks",
 function exceptionHookWithStack( assert ) {
 
 	assert.expect( 2 );
 
 	var done = assert.async(),
 		defer = jQuery.Deferred(),
-		oldWarn = window.console.warn;
+		oldWarn = globalThis.console.warn;
+
+	globalThis.console.warn = function( intro, error, asyncError ) {
+		assert.ok(
+			/cough_up_hairball/.test( intro + "\n" + ( error && error.message || error ) ),
+			"Function mentioned: " + intro + "\n" + ( error && error.message || error )
+		);
 
-	window.console.warn = function( msg, stack ) {
-		assert.ok( /cough_up_hairball/.test( msg ), "Function mentioned: " + msg );
-		assert.ok( /exceptionHookWithStack/.test( stack ), "Stack trace included: \n" + stack );
+		assert.ok(
+			/exceptionHookWithStack/.test( asyncError.message + "\n" + asyncError.stack ),
+			"Stack trace included: " + asyncError.message + "\n" + asyncError.stack
+		);
 	};
+
 	defer.then( function() {
 		jQuery.cough_up_hairball();
 	} ).then( null, function( ) {
-		window.console.warn = oldWarn;
-		delete jQuery.Deferred.getStackHook;
+		globalThis.console.warn = oldWarn;
+		delete jQuery.Deferred.getErrorHook;
 		done();
 	} );