Do not expose kernel process (#11282)

For #10768

The kernel process wasn't used, except in tests.
This is required, as when we spin up the kernel process in the daemon, the process returned by the TS code will return the process daemon and not the kernel process.

This separation ensure we do not rely on it for anything, after all everything we need is in IKernelConnection (ports, etc)

Author: DonJayamanne

src/client/datascience/kernel-launcher/kernelLauncher.ts

@@ -39,9 +39,6 @@ class KernelProcess implements IKernelProcess {
     public get kernelSpec(): Readonly<IJupyterKernelSpec> {
         return this._kernelSpec;
     }
-    public get process(): ChildProcess | undefined {
-        return this._process;
-    }
     public get connection(): Readonly<IKernelConnection> {
         return this._connection;
     }

src/client/datascience/kernel-launcher/types.ts

@@ -2,7 +2,6 @@
 // Licensed under the MIT License.
 'use strict';
 
-import { ChildProcess } from 'child_process';
 import { IDisposable } from 'monaco-editor';
 import { Event } from 'vscode';
 import { InterpreterUri } from '../../common/installer/types';
@@ -27,7 +26,6 @@ export interface IKernelConnection {
 }
 
 export interface IKernelProcess extends IDisposable {
-    process: ChildProcess | undefined;
     readonly connection: Readonly<IKernelConnection>;
     ready: Promise<void>;
     readonly kernelSpec: Readonly<IJupyterKernelSpec>;

src/test/datascience/kernelLauncher.functional.test.ts

@@ -5,7 +5,6 @@
 import { assert } from 'chai';
 import { Uri } from 'vscode';
 
-import { ChildProcess } from 'child_process';
 import { IFileSystem } from '../../client/common/platform/types';
 import { IPythonExecutionFactory } from '../../client/common/process/types';
 import { Resource } from '../../client/common/types';
@@ -14,7 +13,7 @@ import { JupyterZMQBinariesNotFoundError } from '../../client/datascience/jupyte
 import { KernelLauncher } from '../../client/datascience/kernel-launcher/kernelLauncher';
 import { IKernelConnection, IKernelFinder } from '../../client/datascience/kernel-launcher/types';
 import { InterpreterType, PythonInterpreter } from '../../client/interpreter/contracts';
-import { PYTHON_PATH, sleep } from '../common';
+import { PYTHON_PATH, sleep, waitForCondition } from '../common';
 import { DataScienceIocContainer } from './dataScienceIocContainer';
 
 suite('Kernel Launcher', () => {
@@ -50,25 +49,49 @@ suite('Kernel Launcher', () => {
             this.skip();
         } else {
             const kernel = await kernelLauncher.launch(resource, kernelName);
+            const exited = new Promise<boolean>((resolve) => kernel.exited(() => resolve(true)));
 
             assert.isOk<IKernelConnection | undefined>(kernel.connection, 'Connection not found');
-            assert.isOk<ChildProcess | undefined>(kernel.process, 'Child Process not found');
 
+            // It should not exit.
+            assert.isRejected(
+                waitForCondition(() => exited, 5_000, 'Timeout'),
+                'Timeout'
+            );
+
+            // Upon disposing, we should get an exit event within 100ms or less.
+            // If this happens, then we know a process existed.
             kernel.dispose();
+            assert.isRejected(
+                waitForCondition(() => exited, 100, 'Timeout'),
+                'Timeout'
+            );
         }
-    });
+    }).timeout(10_000);
 
     test('Launch from PythonInterpreter', async function () {
         if (!process.env.VSCODE_PYTHON_ROLLING) {
             // tslint:disable-next-line: no-invalid-this
             this.skip();
         } else {
             const kernel = await kernelLauncher.launch(pythonInterpreter, kernelName);
+            const exited = new Promise<boolean>((resolve) => kernel.exited(() => resolve(true)));
+
+            // It should not exit.
+            assert.isRejected(
+                waitForCondition(() => exited, 5_000, 'Timeout'),
+                'Timeout'
+            );
 
             assert.isOk<IKernelConnection | undefined>(kernel.connection, 'Connection not found');
-            assert.isOk<ChildProcess | undefined>(kernel.process, 'Child Process not found');
 
+            // Upon disposing, we should get an exit event within 100ms or less.
+            // If this happens, then we know a process existed.
             kernel.dispose();
+            assert.isRejected(
+                waitForCondition(() => exited, 100, 'Timeout'),
+                'Timeout'
+            );
         }
     });