Stricter browser checks. Drop IE support.

src/_h5ai/public/js/global.js

@@ -0,0 +1,45 @@
+(function check(win) {
+    /* eslint-disable func-names,no-console,no-var */
+
+    if (typeof win !== 'object' || win.window !== win || !win.document) {
+        throw new Error('no-window');
+    }
+
+    var noBrowser = 'no-browser';
+    var docEl = win.document.documentElement;
+    docEl.className = '';
+
+    function assert(msg, expr) {
+        if (!expr) {
+            docEl.className = noBrowser;
+            throw new Error(noBrowser + ': ' + msg);
+        }
+        win.console.log('checked: ' + msg);
+    }
+
+    assert('console', win.console && typeof win.console.log === 'function');
+    assert('assign', win.Object && typeof win.Object.assign === 'function');
+    assert('promise', win.Promise && typeof win.Promise === 'function');
+    assert('history', win.history && typeof win.history.pushState === 'function');
+
+    assert('canvas', (function () {
+        var elem = win.document.createElement('canvas');
+        return elem.getContext && elem.getContext('2d');
+    }()));
+
+    assert('storage', (function () {
+        var key = '#test#';
+        try {
+            win.localStorage.setItem(key, key);
+            win.localStorage.removeItem(key);
+            return true;
+        } catch (e) {
+            return false;
+        }
+    }()));
+
+    /* eslint-enable no-var */
+}(this));
+
+
+// @include "vendor/*.js"