Fix instantly sending RRs

Splits UserActivity into a tristate of 'active' (last < 1s), 'passive' (lasts a
couple of mins) and neither. Read receipts are sent when 'active', read markers
are sent while 'passive'.

Also fixed a document / window mix-up on the 'blur' handler.

Also adds a unit test for UserActivity because it's quite complex now
(and changes UserActivity to make it testable by accessing the singleton
via sharedInstance() rather than exporting it directly).

Fixes https://github.com/vector-im/riot-web/issues/9023

test/UserActivity-test.js

@@ -0,0 +1,134 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import expect from 'expect';
+import lolex from 'lolex';
+import jest from 'jest-mock';
+import EventEmitter from 'events';
+import UserActivity from '../src/UserActivity';
+
+class FakeDomEventEmitter extends EventEmitter {
+    addEventListener(what, l) {
+        this.on(what, l);
+    }
+
+    removeEventListener(what, l) {
+        this.removeListener(what, l);
+    }
+};
+
+describe('UserActivity', function() {
+    let fakeWindow;
+    let fakeDocument;
+    let userActivity;
+    let clock;
+
+    beforeEach(function() {
+        fakeWindow = new FakeDomEventEmitter(),
+        fakeDocument = new FakeDomEventEmitter(),
+        userActivity = new UserActivity(fakeWindow, fakeDocument);
+        userActivity.start();
+        clock = lolex.install();
+    });
+
+    afterEach(function() {
+        userActivity.stop();
+        userActivity = null;
+        clock.uninstall();
+        clock = null;
+    });
+
+    it('should return the same shared instance', function() {
+        expect(UserActivity.sharedInstance()).toBe(UserActivity.sharedInstance());
+    });
+
+    it('should consider user inactive if no activity', function() {
+        expect(userActivity.userCurrentlyActive()).toBe(false);
+    });
+
+    it('should consider user not passive if no activity', function() {
+        expect(userActivity.userCurrentlyPassive()).toBe(false);
+    });
+
+    it('should not consider user active after activity if no window focus', function() {
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(false);
+
+        userActivity._onUserActivity({});
+        expect(userActivity.userCurrentlyActive()).toBe(false);
+        expect(userActivity.userCurrentlyPassive()).toBe(false);
+    });
+
+    it('should consider user active shortly after activity', function() {
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(true);
+
+        userActivity._onUserActivity({});
+        expect(userActivity.userCurrentlyActive()).toBe(true);
+        expect(userActivity.userCurrentlyPassive()).toBe(true);
+        clock.tick(200);
+        expect(userActivity.userCurrentlyActive()).toBe(true);
+        expect(userActivity.userCurrentlyPassive()).toBe(true);
+    });
+
+    it('should consider user not active after 10s of no activity', function() {
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(true);
+
+        userActivity._onUserActivity({});
+        clock.tick(10000);
+        expect(userActivity.userCurrentlyActive()).toBe(false);
+    });
+
+    it('should consider user passive after 10s of no activity', function() {
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(true);
+
+        userActivity._onUserActivity({});
+        clock.tick(10000);
+        expect(userActivity.userCurrentlyPassive()).toBe(true);
+    });
+
+    it('should not consider user passive after 10s if window un-focused', function() {
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(true);
+
+        userActivity._onUserActivity({});
+        clock.tick(10000);
+
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(false);
+        fakeWindow.emit('blur', {});
+
+        expect(userActivity.userCurrentlyPassive()).toBe(false);
+    });
+
+    it('should not consider user passive after 3 mins', function() {
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(true);
+
+        userActivity._onUserActivity({});
+        clock.tick(3 * 60 * 1000);
+
+        expect(userActivity.userCurrentlyPassive()).toBe(false);
+    });
+
+    it('should extend timer on activity', function() {
+        fakeDocument.hasFocus = jest.fn().mockReturnValue(true);
+
+        userActivity._onUserActivity({});
+        clock.tick(1 * 60 * 1000);
+        userActivity._onUserActivity({});
+        clock.tick(1 * 60 * 1000);
+        userActivity._onUserActivity({});
+        clock.tick(1 * 60 * 1000);
+
+        expect(userActivity.userCurrentlyPassive()).toBe(true);
+    });
+});