only refresh view when the server URL changes (MM-34565) (#2082) (#2094)

* only refresh view when the server URL changes (MM-34565)

Create views of current and incoming tabs indexed
by unique [URL, TABTYPE] tuples, and diffing them.
Tuples that are identical are recycled, merely
porting the new server name over.

* lint fixes

* WIP

* linting

* remove dependency on by, duad

* provide a more exaplanatory name for TabView.prototype.tuple (urlTypeTuple)

* minor improvements in viewManager

- remove stateful behaviour from makeView
- more descriptive variable names when looping
- create new arrays before sorting (sort is in-place by default)

* resolve linting errors

src/common/tabs/BaseTabView.ts

@@ -1,9 +1,11 @@
 // Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
 // See LICENSE.txt for license information.
 
+import {Tuple as tuple} from '@bloomberg/record-tuple-polyfill';
+
 import {MattermostServer} from 'common/servers/MattermostServer';
 
-import {getTabViewName, TabType, TabView} from './TabView';
+import {getTabViewName, TabType, TabView, TabTuple} from './TabView';
 
 export default abstract class BaseTabView implements TabView {
     server: MattermostServer;
@@ -14,6 +16,9 @@ export default abstract class BaseTabView implements TabView {
     get name(): string {
         return getTabViewName(this.server.name, this.type);
     }
+    get urlTypeTuple(): TabTuple {
+        return tuple(this.url.href, this.type) as TabTuple;
+    }
     get url(): URL {
         throw new Error('Not implemented');
     }

src/common/tabs/TabView.ts

@@ -13,6 +13,7 @@ export const TAB_MESSAGING = 'TAB_MESSAGING';
 export const TAB_FOCALBOARD = 'TAB_FOCALBOARD';
 export const TAB_PLAYBOOKS = 'TAB_PLAYBOOKS';
 export type TabType = typeof TAB_MESSAGING | typeof TAB_FOCALBOARD | typeof TAB_PLAYBOOKS;
+export type TabTuple = [string, TabType];
 
 export interface TabView {
     server: MattermostServer;
@@ -21,6 +22,7 @@ export interface TabView {
     get type(): TabType;
     get url(): URL;
     get shouldNotify(): boolean;
+    get urlTypeTuple(): TabTuple;
 }
 
 export function getDefaultTeamWithTabsFromTeam(team: Team) {