fix(telemetry): session_end not caching events

When the user shutdown their extension gracefully our mechanism that
would cache any pending metrics for the next startup would not save to disk.

This was due to the VS Code FS implementation being used, but it will not work since
the function it is called in is called by `deactivate()` which does not have access to
vscode apis on shutdown.

Solution is to swap it with the node fs implementation

Signed-off-by: nkomonen-amazon <[email protected]>

Author: nkomonen-amazon

packages/core/src/shared/telemetry/telemetryService.ts

@@ -20,6 +20,7 @@ import { ClassToInterfaceType } from '../utilities/tsUtils'
 import { getClientId, validateMetricEvent } from './util'
 import { telemetry, MetricBase } from './telemetry'
 import fs from '../fs/fs'
+import fsNode from 'fs/promises'
 import * as collectionUtil from '../utilities/collectionUtils'
 
 export type TelemetryService = ClassToInterfaceType<DefaultTelemetryService>
@@ -116,7 +117,10 @@ export class DefaultTelemetryService {
             })
 
             try {
-                await fs.writeFile(this.persistFilePath, JSON.stringify(this._eventQueue))
+                /**
+                 * This function runs in deactivate() so we must use node fs. See the vscode behavior doc for more info.
+                 */
+                await fsNode.writeFile(this.persistFilePath, JSON.stringify(this._eventQueue))
             } catch {}
         }
     }