plugin: stub setKeysForSync

The commit stubs the method `setKeysForSync` as it is currently not
supported by the framework and likely uses vscode online services to
store data across machines.

Signed-off-by: vince-fugnitto <[email protected]>

packages/plugin-ext/src/plugin/plugin-manager.ts

@@ -33,7 +33,7 @@ import * as theia from '@theia/plugin';
 import { join } from './path';
 import { EnvExtImpl } from './env';
 import { PreferenceRegistryExtImpl } from './preference-registry';
-import { Memento, KeyValueStorageProxy } from './plugin-storage';
+import { Memento, KeyValueStorageProxy, GlobalState } from './plugin-storage';
 import { ExtPluginApi } from '../common/plugin-ext-api-contribution';
 import { RPCProtocol } from '../common/rpc-protocol';
 import { Emitter } from '@theia/core/lib/common/event';
@@ -372,7 +372,7 @@ export class PluginManagerExtImpl implements PluginManagerExt, PluginManager {
         const pluginContext: theia.PluginContext = {
             extensionPath: plugin.pluginFolder,
             extensionUri: Uri.file(plugin.pluginFolder),
-            globalState: new Memento(plugin.model.id, true, this.storageProxy),
+            globalState: new GlobalState(plugin.model.id, true, this.storageProxy),
             workspaceState: new Memento(plugin.model.id, false, this.storageProxy),
             subscriptions: subscriptions,
             asAbsolutePath: asAbsolutePath,

packages/plugin-ext/src/plugin/plugin-storage.ts

@@ -60,6 +60,14 @@ export class Memento implements theia.Memento {
     }
 }
 
+export class GlobalState extends Memento {
+
+    setKeysForSync(keys: readonly string[]): void {
+        /** no-op. */
+    }
+
+}
+
 /**
  * Singleton.
  * Is used to proxy storage requests to main side.

packages/plugin/src/theia.d.ts

@@ -3064,7 +3064,22 @@ declare module '@theia/plugin' {
          * A memento object that stores state independent
          * of the current opened [workspace](#workspace.workspaceFolders).
          */
-        globalState: Memento;
+        globalState: Memento & {
+            /**
+             * Set the keys whose values should be synchronized across devices when synchronizing user-data
+             * like configuration, extensions, and mementos.
+             *
+             * Note that this function defines the whole set of keys whose values are synchronized:
+             *  - calling it with an empty array stops synchronization for this memento
+             *  - calling it with a non-empty array replaces all keys whose values are synchronized
+             *
+             * For any given set of keys this function needs to be called only once but there is no harm in
+             * repeatedly calling it.
+             *
+             * @param keys The set of keys whose values are synced.
+             */
+            setKeysForSync(keys: readonly string[]): void;
+        };
 
         /**
          * A storage utility for secrets.