feat: Add a Python language server

build/esbuild/build.ts

@@ -43,7 +43,7 @@ const deskTopNodeModulesToExternalize = [
     // Lazy loaded modules.
     'vscode-languageclient/node',
     '@jupyterlab/nbformat',
-    'vscode-jsonrpc' // Used by a few modules, might as well pull this out, instead of duplicating it in separate bundles.
+    'vscode-jsonrpc'
 ];
 const commonExternals = [
     'log4js',
@@ -226,10 +226,15 @@ function createConfig(
         inject.push(path.join(__dirname, 'jquery.js'));
     }
     // Create a copy to avoid mutating the original arrays
-    const external = [...(target === 'web' ? webExternals : commonExternals)];
+    let external = [...(target === 'web' ? webExternals : commonExternals)];
     if (source.toLowerCase().endsWith('extension.node.ts')) {
         external.push(...desktopExternals);
     }
+    // When building vscode-languageclient, bundle vscode-jsonrpc into it
+    // to avoid ESM/CommonJS interop issues at runtime
+    if (source.includes('vscode-languageclient')) {
+        external = external.filter((e) => e !== 'vscode-jsonrpc');
+    }
     const isPreRelease = isDevbuild || process.env.IS_PRE_RELEASE_VERSION_OF_JUPYTER_EXTENSION === 'true';
     const releaseVersionScriptFile = isPreRelease ? 'release.pre-release.js' : 'release.stable.js';
     const alias = {
@@ -534,20 +539,18 @@ async function copyNodeGypBuild() {
     await fs.ensureDir(target);
     await fs.copy(source, target, { recursive: true });
 }
+
 async function buildVSCodeJsonRPC() {
     const source = path.join(extensionFolder, 'node_modules', 'vscode-jsonrpc');
     const target = path.join(extensionFolder, 'dist', 'node_modules', 'vscode-jsonrpc', 'index.js');
     await fs.ensureDir(path.dirname(target));
     const fullPath = require.resolve(source);
-    const contents = `
-/* --------------------------------------------------------------------------------------------
- * Copyright (c) Microsoft Corporation. All rights reserved.
- * Licensed under the MIT License. See License.txt in the project root for license information.
- * ----------------------------------------------------------------------------------------- */
-'use strict';
-
-module.exports = require('./index');`;
+    // ESM re-export for node.js entry point
+    const contents = `export * from './index.js';`;
     await fs.writeFile(path.join(path.dirname(target), 'node.js'), contents);
+    // Add package.json for ESM module resolution
+    const packageJson = JSON.stringify({ type: 'module', main: './index.js' }, null, 2);
+    await fs.writeFile(path.join(path.dirname(target), 'package.json'), packageJson);
     return build(fullPath, target, {
         target: 'desktop',
         watch: false

cspell.json

@@ -57,6 +57,7 @@
         "pids",
         "Pids",
         "plotly",
+        "pylsp",
         "PYTHONHOME",
         "Reselecting",
         "scipy",

package.json

@@ -2547,7 +2547,7 @@
         "vega-embed": "^7.1.0",
         "vega-lite": "^6.4.1",
         "vscode-debugprotocol": "^1.41.0",
-        "vscode-languageclient": "8.0.2-next.5",
+        "vscode-languageclient": "^9.0.1",
         "vscode-tas-client": "^0.1.84",
         "ws": "^6.2.3",
         "zeromq": "^6.5.0",

src/commands.ts

@@ -181,8 +181,6 @@ export interface ICommandNameArgumentTypeMapping {
     [DSCommands.RunAndDebugCell]: [NotebookCell];
     [DSCommands.RunByLineNext]: [NotebookCell];
     [DSCommands.RunByLineStop]: [NotebookCell];
-    [DSCommands.ReplayPylanceLog]: [Uri];
-    [DSCommands.ReplayPylanceLogStep]: [];
     [DSCommands.InstallPythonExtensionViaKernelPicker]: [];
     [DSCommands.InstallPythonViaKernelPicker]: [];
     [DSCommands.ContinueEditSessionInCodespace]: [];

src/extension.common.ts

@@ -18,7 +18,6 @@ import {
 import {
     STANDARD_OUTPUT_CHANNEL,
     JUPYTER_OUTPUT_CHANNEL,
-    PylanceExtension,
     PythonExtension,
     Telemetry,
     PythonEnvironmentExtension
@@ -39,7 +38,6 @@ import { IServiceContainer, IServiceManager } from './platform/ioc/types';
 import { initializeLoggers as init, logger } from './platform/logging';
 import { ILogger } from './platform/logging/types';
 import { getJupyterOutputChannel } from './standalone/devTools/jupyterOutputChannel';
-import { isUsingPylance } from './standalone/intellisense/notebookPythonPathService';
 import { noop } from './platform/common/utils/misc';
 import { sendErrorTelemetry } from './platform/telemetry/startupTelemetry';
 import { StopWatch } from './platform/common/utils/stopWatch';
@@ -77,16 +75,6 @@ export async function initializeLoggers(
     } else {
         standardOutputChannel.appendLine('Python Environment Extension not installed.');
     }
-    const pylanceExtension = extensions.getExtension(PylanceExtension);
-    if (pylanceExtension) {
-        standardOutputChannel.appendLine(
-            `Pylance Extension Version${isUsingPylance() ? '' : ' (Not Used) '}: ${
-                pylanceExtension.packageJSON['version']
-            }.`
-        );
-    } else {
-        standardOutputChannel.appendLine('Pylance Extension not installed.');
-    }
     if (options?.platform) {
         standardOutputChannel.appendLine(`Platform: ${options.platform} (${options.arch}).`);
     }