better error handling in checkup

www/assert/assertions.js

@@ -6,7 +6,35 @@ define([], function () {
         var MESSAGES = [];
         var assert = function (test, msg) {
             MESSAGES.push(msg || false);
-            ASSERTS.push(function (cb, i) {
+            ASSERTS.push(function (_cb, i) {
+                var called = false;
+                var to;
+                var cb = function (arg) {
+                    if (to) {
+                        clearTimeout(to);
+                        to = undefined;
+                    }
+
+                    if (called) { return; }
+                    called = true;
+                    _cb(arg);
+                };
+
+                var _msg = document.createElement('span');
+                _msg.innerText = "An unexpected error occurred. See your browser's console for more details";
+                if (msg && !msg.innerText) {
+                    msg.innerText = _msg.innerText;
+                }
+
+                to = setTimeout(function () {
+                    cb({
+                        test: i,
+                        message: msg || _msg,
+                        output: "TIMEOUT",
+                    });
+                }, 25000);
+
+                try {
                     test(function (result) {
                         if (result === true) {
                             passed++;
@@ -14,11 +42,29 @@ define([], function () {
                         } else {
                             cb({
                                 test: i,
-                            message: msg,
+                                message: msg || _msg,
                                 output: result,
                             });
                         }
                     }, msg);
+                } catch (err) {
+                    console.error(err);
+                    msg.innerText = `Synchronous error thrown (${(err.message || err)}). See console for more details.`;
+
+                    //from ${err.fileName} line ${err.lineNumber}`;
+                    cb({
+                        test: i,
+                        message: msg || _msg,
+                        output: {
+                            message: err.message,
+                            file: err.fileName,
+                            line: err.lineNumber,
+                            stack: typeof(err.stack) === 'string'?
+                                err.stack.split('\n'):
+                                err.stack,
+                        },
+                    });
+                }
             });
         };
 

www/checkup/dependency-warning.js

@@ -1,4 +1,15 @@
 (function () { 
+    var h = (tag, children) => {
+        var el = document.createElement(tag);
+        children.forEach(child => {
+            if (typeof(child) === 'string') {
+                return void el.appendChild(document.createTextNode(child));
+            }
+            el.appendChild(child);
+        });
+        return el;
+    };
+
     var first = true;
     window.addEventListener('error', function (ev) {
         if (!ev) { return; }
@@ -7,11 +18,25 @@
         var nodeName = srcElement.nodeName;
         if (nodeName !== 'SCRIPT') { return; }
         var src = srcElement.src;
-        if (!/\/bower_components\/.*/.test(src)) { return; }
+
+        if (/\/api\/.*/.test(src)) {
+            console.error("A serverside API endpoint could not be reached.", src);
+        }
+
+        //if (!/\/bower_components\/.*/.test(src)) { return; }
         if (first) {
-            document.write(`<p>It's possible that this server's administrators forgot to install its client-side dependencies with 'bower update'.</p>`);
+            document.body.appendChild(h('h1', ['Oops!']));
+            document.body.appendChild(h('p', [
+                `It's possible that this server's administrators forgot to install its client-side dependencies with 'bower update',`,
+                ` or that some other required resource couldn't be loaded.`,
+                ` See your browser's console for more details.`,
+            ]));
             first = false;
         }
-        document.write(`<p>Failed to load <code>${src}</code>.</p>`);
+        document.body.appendChild(h('p', [
+            'Failed to load ',
+            h('code', [src]),
+            '.',
+        ]));
     }, true);
 }());

www/checkup/index.html

@@ -3,10 +3,10 @@
 <head>
     <meta content="text/html; charset=utf-8" http-equiv="content-type"/>
     <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
-    <script type="text/javascript" src="/checkup/dependency-warning.js?ver=1.0.0"></script>
-    <script data-bootload="main.js" data-main="/common/boot.js" src="/bower_components/requirejs/require.js"></script>
 </head>
 <body>
 <div id="cp-progress"></div>
 <iframe-placeholder>
+<script type="text/javascript" src="/checkup/dependency-warning.js?ver=1.0.0"></script>
+<script data-bootload="main.js" data-main="/common/boot.js" src="/bower_components/requirejs/require.js"></script>