fix: register event listeners for proper disposal of client provider (#…

…498)

This adds the disposable returned by the event registrations to
`this.subscriptions` so that calling `dispose` will get rid of all event
listeners.

This will help with lean4web, but is probably generally the right thing
to do here.

vscode-lean4/src/utils/clientProvider.ts

@@ -60,7 +60,7 @@ export class LeanClientProvider implements Disposable {
         this.installer = installer
 
         // we must setup the installChanged event handler first before any didOpenEditor calls.
-        installer.installChanged(async (uri: FileUri) => await this.onInstallChanged(uri))
+        this.subscriptions.push(installer.installChanged(async (uri: FileUri) => await this.onInstallChanged(uri)))
 
         window.visibleTextEditors.forEach(e => this.didOpenEditor(e.document))
         this.subscriptions.push(
@@ -79,24 +79,26 @@ export class LeanClientProvider implements Disposable {
             commands.registerCommand('lean4.stopServer', () => this.stopActiveClient()),
         )
 
-        workspace.onDidOpenTextDocument(document => this.didOpenEditor(document))
+        this.subscriptions.push(workspace.onDidOpenTextDocument(document => this.didOpenEditor(document)))
 
-        workspace.onDidChangeWorkspaceFolders(event => {
-            // Remove all clients that are not referenced by any folder anymore
-            if (event.removed.length === 0) {
-                return
-            }
-            this.clients.forEach((client, key) => {
-                if (client.folderUri.scheme === 'untitled' || getWorkspaceFolderUri(client.folderUri)) {
+        this.subscriptions.push(
+            workspace.onDidChangeWorkspaceFolders(event => {
+                // Remove all clients that are not referenced by any folder anymore
+                if (event.removed.length === 0) {
                     return
                 }
+                this.clients.forEach((client, key) => {
+                    if (client.folderUri.scheme === 'untitled' || getWorkspaceFolderUri(client.folderUri)) {
+                        return
+                    }
 
-                logger.log(`[ClientProvider] onDidChangeWorkspaceFolders removing client for ${key}`)
-                this.clients.delete(key)
-                client.dispose()
-                this.clientRemovedEmitter.fire(client)
-            })
-        })
+                    logger.log(`[ClientProvider] onDidChangeWorkspaceFolders removing client for ${key}`)
+                    this.clients.delete(key)
+                    client.dispose()
+                    this.clientRemovedEmitter.fire(client)
+                })
+            }),
+        )
     }
 
     getActiveClient(): LeanClient | undefined {