Switch option observer tests to jest

.vscode/extensions.json

@@ -1,6 +1,7 @@
 {
     "recommendations": [
         "dbaeumer.vscode-eslint",
-        "esbenp.prettier-vscode"
+        "esbenp.prettier-vscode",
+        "orta.vscode-jest"
     ]
 }

__mocks__/vscode.ts

@@ -0,0 +1,15 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { getFakeVsCode } from '../test/unitTests/testAssets/fakes';
+import * as vscodeAdapter from '../src/vscodeAdapter';
+
+// This module creates a manual mock for the vscode module for running in unit tests.
+// Jest will automatically pick this up as it is in the __mocks__ directory next to node_modules.
+
+// We can consider switching to an actual jest mock (instead of this manual fake) once we entirely
+// remove the old test framework (mocha/chai).
+const vscode: vscodeAdapter.vscode = getFakeVsCode();
+module.exports = vscode;

jest.config.ts

@@ -0,0 +1,20 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+import type { Config } from 'jest';
+
+const config: Config = {
+    verbose: true,
+    preset: 'ts-jest',
+    testEnvironment: 'node',
+    transformIgnorePatterns: ['/dist/.+\\.js'],
+    modulePathIgnorePatterns: ['out'],
+    /* Specify jest to only run tests in jestUnitTests.
+     * We also have to include the __mocks__ folder.  That folder must be next to node_modules so we can't move it,
+     * but if we specify roots, jest won't automatically pick it up.  So we have to specify it here.
+     */
+    roots: ['<rootDir>/test/jestUnitTests', '<rootDir>/__mocks__'],
+};
+
+export default config;

l10n/bundle.l10n.json

@@ -118,11 +118,15 @@
   "View Debug Docs": "View Debug Docs",
   "Ignore": "Ignore",
   "Run and Debug: A valid browser is not installed": "Run and Debug: A valid browser is not installed",
+  "dotnet.server.useOmnisharp option has changed. Please reload the window to apply the change": "dotnet.server.useOmnisharp option has changed. Please reload the window to apply the change",
+  "Reload Window": "Reload Window",
+  "C# configuration has changed. Would you like to relaunch the Language Server with your changes?": "C# configuration has changed. Would you like to relaunch the Language Server with your changes?",
+  "Restart Language Server": "Restart Language Server",
   "Your workspace has multiple Visual Studio Solution files; please select one to get full IntelliSense.": "Your workspace has multiple Visual Studio Solution files; please select one to get full IntelliSense.",
   "Choose": "Choose",
   "Choose and set default": "Choose and set default",
   "Do not load any": "Do not load any",
-  "Restart Language Server": "Restart Language Server",
+  "C# configuration has changed. Would you like to reload the window to apply your changes?": "C# configuration has changed. Would you like to reload the window to apply your changes?",
   "pipeArgs must be a string or a string array type": "pipeArgs must be a string or a string array type",
   "Name not defined in current configuration.": "Name not defined in current configuration.",
   "Configuration \"{0}\" in launch.json does not have a {1} argument with {2} for remote process listing.": "Configuration \"{0}\" in launch.json does not have a {1} argument with {2} for remote process listing.",