MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / resources / src / mediawiki / mediawiki.errorLogger.js

diff --git a/resources/src/mediawiki/mediawiki.errorLogger.js b/resources/src/mediawiki/mediawiki.errorLogger.js
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+++ b/resources/src/mediawiki/mediawiki.errorLogger.js
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+/**
+ * Try to catch errors in modules which don't do their own error handling.
+ *
+ * @class mw.errorLogger
+ * @singleton
+ */
+( function ( mw ) {
+       'use strict';
+
+       mw.errorLogger = {
+               /**
+                * Fired via mw.track when an error is not handled by local code and is caught by the
+                * window.onerror handler.
+                *
+                * @event global_error
+                * @param {string} errorMessage Error errorMessage.
+                * @param {string} url URL where error was raised.
+                * @param {number} lineNumber Line number where error was raised.
+                * @param {number} [columnNumber] Line number where error was raised. Not all browsers
+                *   support this.
+                * @param {Error|Mixed} [errorObject] The error object. Typically an instance of Error, but anything
+                *   (even a primitive value) passed to a throw clause will end up here.
+                */
+
+               /**
+                * Install a window.onerror handler that will report via mw.track, while preserving
+                * any previous handler.
+                *
+                * @param {Object} window
+                */
+               installGlobalHandler: function ( window ) {
+                       // We will preserve the return value of the previous handler. window.onerror works the
+                       // opposite way than normal event handlers (returning true will prevent the default
+                       // action, returning false will let the browser handle the error normally, by e.g.
+                       // logging to the console), so our fallback old handler needs to return false.
+                       var oldHandler = window.onerror || function () { return false; };
+
+                       /**
+                        * Dumb window.onerror handler which forwards the errors via mw.track.
+                        *
+                        * @param {string} errorMessage
+                        * @param {string} url
+                        * @param {number} lineNumber
+                        * @param {number} [columnNumber]
+                        * @param {Error|Mixed} [errorObject]
+                        * @return {boolean} True to prevent the default action
+                        * @fires global_error
+                        */
+                       window.onerror = function ( errorMessage, url, lineNumber, columnNumber, errorObject ) {
+                               mw.track( 'global.error', { errorMessage: errorMessage, url: url,
+                                       lineNumber: lineNumber, columnNumber: columnNumber, errorObject: errorObject } );
+                               return oldHandler.apply( this, arguments );
+                       };
+               }
+       };
+
+       mw.errorLogger.installGlobalHandler( window );
+}( mediaWiki ) );