test browser-dependent SharedArrayBuffer support in checkup

include debugging information in final report
for when browser vendors inevitably break APIs again

www/checkup/app-checkup.less

@@ -14,11 +14,15 @@ html, body {
 
     .report {
         font-size: 30px;
-        max-width: 50%;
+        max-width: 26em;
         margin: auto;
         padding-top: 15px;
     }
 
+    .summary, .failure, .error, .success {
+        margin-bottom: 1em;
+    }
+
     .pending {
         border: 1px solid @cryptpad_text_col;
         .fa {
@@ -46,6 +50,10 @@ html, body {
         td {
             padding: 5px;
             border: 1px solid @cryptpad_text_col;
+            font-size: 60%;
+        }
+        td:nth-child(2) {
+            word-break: break-word;
         }
     }
 
@@ -72,7 +80,12 @@ html, body {
             color: @cryptpad_color_link;
         }
     }
-    .cp-app-checkup-version {
+
+    .cp-notice-browser, .cp-notice-details, .cp-notice-other {
+        font-size: 70%;
+    }
+
+    .cp-app-checkup-version, .cp-app-checkup-browser {
         text-decoration: underline;
     }
 

www/checkup/checkup-tools.js

@@ -0,0 +1,36 @@
+define([
+], function () {
+    var Tools = {};
+    Tools.supportsSharedArrayBuffers = function () {
+        try {
+            return Object.prototype.toString.call(new window.WebAssembly.Memory({
+                shared: true,
+                initial: 0,
+                maximum: 0,
+            }).buffer) === '[object SharedArrayBuffer]';
+        } catch (err) {
+            console.error(err);
+        }
+        return false;
+    };
+
+
+    Tools.isSafari = function () {
+        return navigator.vendor.match(/apple/i);
+    };
+
+    Tools.isChrome = function () {
+        return navigator.vendor.match(/google/i);
+    };
+
+    Tools.guessBrowser = function () {
+        if (Tools.isChrome()) { return 'chrome/blink'; }
+        if (Tools.isSafari()) { return 'safari/webkit'; }
+        if (navigator.userAgent.match(/firefox\//i)) { return 'firefox/gecko'; }
+        if (navigator.userAgent.match(/edge\//i)) { return 'edge/edgehtml'; }
+        if (navigator.userAgent.match(/trident\//i)) { return 'ie/trident'; }
+        return navigator.userAgent + "\n" + navigator.vendor;
+    };
+
+    return Tools;
+});

www/checkup/main.js

@@ -13,13 +13,14 @@ define([
     '/common/pinpad.js',
     '/common/outer/network-config.js',
     '/customize/pages.js',
+    '/checkup/checkup-tools.js',
 
     '/bower_components/tweetnacl/nacl-fast.min.js',
     'css!/bower_components/components-font-awesome/css/font-awesome.min.css',
     'less!/checkup/app-checkup.less',
 ], function ($, ApiConfig, Assertions, h, Messages, DomReady,
             nThen, SFCommonO, Login, Hash, Util, Pinpad,
-            NetConfig, Pages) {
+            NetConfig, Pages, Tools) {
     var Assert = Assertions();
     var trimSlashes = function (s) {
         if (typeof(s) !== 'string') { return s; }
@@ -703,6 +704,81 @@ define([
         });
     });
 
+    var safariGripe = function () {
+        return h('p.cp-notice-other', 'This is expected because Safari and platforms that use its engine lack commonly supported functionality.');
+    };
+
+    var chromeGripe = function () {
+        return h('p.cp-notice-other', "This is expected because the developers of Google chrome's engine intentionally disabled support in cross-origin contexts. We are working  on an alternate solution.");
+    };
+
+    var browserIssue = function () {
+        return h('p.cp-notice-other', 'This test checks for the presence of features in your browser and is not necessarily caused by server misconfiguration.');
+    };
+
+    assert(function (cb, msg) {
+        cb = Util.once(cb);
+        setWarningClass(msg);
+        var notice = h('span', [
+            h('p', 'It appears that some features required for Office file format conversion are not present.'),
+        ]);
+
+        msg.appendChild(notice);
+
+        var expected = [
+            'Atomics',
+            'SharedArrayBuffer',
+            'WebAssembly',
+            ['WebAssembly', 'Memory'],
+            ['WebAssembly', 'instantiate'],
+            ['WebAssembly', 'instantiateStreaming'],
+            ['Buffer', 'from'],
+
+            'SharedWorker',
+            'worker',
+            'crossOriginIsolated',
+        ];
+
+        var responses = {};
+
+        nThen(function (w) {
+            deferredPostMessage({
+                command: 'CHECK_JS_APIS',
+                content: {
+                    globals: expected,
+                },
+            }, w(function (response) {
+                Util.extend(responses, response);
+            }));
+
+            deferredPostMessage({
+                command: 'FANCY_API_CHECKS',
+                content: {
+                },
+            }, w(function (response) {
+                Util.extend(responses, response);
+            }));
+        }).nThen(function () {
+            if (!responses.Atomics || !responses.WebAssembly) {
+                return void cb(responses);
+            }
+            if (responses.SharedArrayBuffer || responses.SharedArrayBufferFallback) {
+                return cb(true);
+            }
+
+            if (Tools.isSafari()) {
+                notice.appendChild(safariGripe());
+            }
+            if (Tools.isChrome()) {
+                notice.appendChild(chromeGripe());
+            }
+
+            notice.appendChild(browserIssue());
+
+            return void cb(response);
+        });
+    });
+
     var isHTTPS = function (host) {
         return /^https:\/\//.test(host);
     };
@@ -831,7 +907,7 @@ define([
     var failureReport = function (obj) {
         var printableValue = obj.output;
         try {
-            printableValue = JSON.stringify(obj.output);
+            printableValue = JSON.stringify(obj.output, null, ' ');
         } catch (err) {
             console.error(err);
         }
@@ -840,7 +916,7 @@ define([
             h('h5', obj.message),
             h('table', [
                 row(["Failed test number", obj.test + 1]),
-                row(["Returned value", code(printableValue)]),
+                row(["Returned value", h('pre', code(printableValue))]),
             ]),
         ]);
     };
@@ -849,7 +925,7 @@ define([
     var $progress = $('#cp-progress');
 
     var versionStatement = function () {
-        return h('p', [
+        return h('p.cp--notice-version', [
             "This instance is running ",
             h('span.cp-app-checkup-version',[
                 "CryptPad",
@@ -860,6 +936,16 @@ define([
         ]);
     };
 
+    var browserStatement = function () {
+        var name = Tools.guessBrowser();
+        if (!name) { return; }
+        return h('p.cp-notice-browser', [
+            "You appear to be using a ",
+            h('span.cp-app-checkup-browser', name),
+            ' browser to view this page.',
+        ]);
+    };
+
     Assert.run(function (state) {
         var errors = state.errors;
         var failed = errors.length;
@@ -870,10 +956,11 @@ define([
 
         var failedDetails = "Details found below";
         var successDetails = "This checkup only tests the most common configuration issues. You may still experience errors or incorrect behaviour.";
-        var details = h('p', failed? failedDetails: successDetails);
+        var details = h('p.cp-notice-details', failed? failedDetails: successDetails);
 
         var summary = h('div.summary.' + statusClass, [
             versionStatement(),
+            browserStatement(),
             h('p', Messages._getKey('assert_numberOfTestsPassed', [
                 state.passed,
                 state.total

www/checkup/sandbox/main.js

@@ -1,10 +1,12 @@
 define([
     'jquery',
+    '/common/common-util.js',
+    '/checkup/checkup-tools.js',
 
     '/bower_components/tweetnacl/nacl-fast.min.js',
     'css!/bower_components/components-font-awesome/css/font-awesome.min.css',
     'less!/checkup/app-checkup.less',
-], function ($) {
+], function ($, Util, Tools) {
     var postMessage = function (content) {
         window.parent.postMessage(JSON.stringify(content), '*');
     };
@@ -26,6 +28,26 @@ define([
         });
     };
 
+    COMMANDS.CHECK_JS_APIS = function (content, cb) {
+        var globalAPIs = content['globals'] || [];
+        var response = {};
+        globalAPIs.forEach(function (key) {
+            if (Array.isArray(key)) {
+                response[key.join('.')] = Boolean(Util.find(window, key));
+                return;
+            }
+
+            response[key] = Boolean(window[key]);
+        });
+        cb(response);
+    };
+
+    COMMANDS.FANCY_API_CHECKS = function (content, cb) {
+        cb({
+            SharedArrayBufferFallback: Tools.supportsSharedArrayBuffers(),
+        });
+    };
+
     window.addEventListener("message", function (event) {
         var txid, command;
         if (event && event.data) {