init the awkward code

static/html/jspaint/src/error-handling-basic.js

@@ -0,0 +1,23 @@
+/* eslint-disable no-useless-concat */
+/* eslint-disable no-alert */
+
+// use only ES5 syntax for this script
+// set up basic global error handling, which we can override later
+window.onerror = function (msg, url, lineNo, columnNo, error) {
+	var string = msg.toLowerCase();
+	var substring = "script error";
+	if (string.indexOf(substring) > -1) {
+		alert('Script Error: See Browser Console for Detail');
+	} else {
+		// try {
+		// 	// try-catch in case of circular references or old browsers without JSON.stringify
+		// 	error = JSON.stringify(error);
+		// } catch (e) {}
+		alert('Internal application error: ' + msg + '\n\n' + 'URL: ' + url + '\n' + 'Line: ' + lineNo + '\n' + 'Column: ' + columnNo);
+	}
+	return false;
+};
+
+window.onunhandledrejection = function (event) {
+	alert('Unhandled Rejection: ' + event.reason);
+}