Ensure we start watching environments when activating discovery component (microsoft#19827)

Ensure we start watchers and create workspace related objects when
activating discovery component

Author: Kartik Raj

src/client/pythonEnvironments/base/locators/common/resourceBasedLocator.ts

@@ -4,6 +4,7 @@
 import { IDisposable } from '../../../../common/types';
 import { createDeferred, Deferred } from '../../../../common/utils/async';
 import { Disposables } from '../../../../common/utils/resourceLifecycle';
+import { traceError } from '../../../../logging';
 import { PythonEnvInfo } from '../../info';
 import { IPythonEnvsIterator, Locator, PythonLocatorQuery } from '../../locator';
 
@@ -28,15 +29,22 @@ export abstract class LazyResourceBasedLocator<I = PythonEnvInfo> extends Locato
 
     private watchersReady?: Deferred<void>;
 
+    /**
+     * This can be used to initialize resources when subclasses are created.
+     */
+    protected async activate(): Promise<void> {
+        await this.ensureResourcesReady();
+        // There is not need to wait for the watchers to get started.
+        this.ensureWatchersReady().ignoreErrors();
+    }
+
     public async dispose(): Promise<void> {
         await this.disposables.dispose();
     }
 
     public async *iterEnvs(query?: PythonLocatorQuery): IPythonEnvsIterator<I> {
-        await this.ensureResourcesReady();
+        await this.activate();
         yield* this.doIterEnvs(query);
-        // There is not need to wait for the watchers to get started.
-        this.ensureWatchersReady().ignoreErrors();
     }
 
     /**
@@ -87,7 +95,10 @@ export abstract class LazyResourceBasedLocator<I = PythonEnvInfo> extends Locato
             return;
         }
         this.resourcesReady = createDeferred<void>();
-        await this.initResources();
+        await this.initResources().catch((ex) => {
+            traceError(ex);
+            this.resourcesReady?.reject(ex);
+        });
         this.resourcesReady.resolve();
     }
 
@@ -97,7 +108,10 @@ export abstract class LazyResourceBasedLocator<I = PythonEnvInfo> extends Locato
             return;
         }
         this.watchersReady = createDeferred<void>();
-        await this.initWatchers();
+        await this.initWatchers().catch((ex) => {
+            traceError(ex);
+            this.watchersReady?.reject(ex);
+        });
         this.watchersReady.resolve();
     }
 }

src/client/pythonEnvironments/base/locators/lowLevel/fsWatchingLocator.ts

@@ -84,6 +84,7 @@ export abstract class FSWatchingLocator<I = PythonEnvInfo> extends LazyResourceB
         private readonly watcherKind: FSWatcherKind = FSWatcherKind.Global,
     ) {
         super();
+        this.activate().ignoreErrors();
     }
 
     protected async initWatchers(): Promise<void> {

src/client/pythonEnvironments/base/locators/wrappers.ts

@@ -59,6 +59,7 @@ export class WorkspaceLocators<I = PythonEnvInfo> extends LazyResourceBasedLocat
 
     constructor(private readonly watchRoots: WatchRootsFunc, private readonly factories: WorkspaceLocatorFactory<I>[]) {
         super();
+        this.activate().ignoreErrors();
     }
 
     public async dispose(): Promise<void> {