Address sourcemap.test.ts flakiness

This commit addresses "Client is not running" test flakiness in
sourcemap.test.ts by calling getActivatedExtension(), which ensures that
the language server is fully up and running, before the test starts.

Author: cklin

extensions/ql-vscode/test/vscode-tests/cli-integration/sourcemap.test.ts

@@ -4,13 +4,21 @@ import { tmpDir } from "../../../src/tmp-dir";
 import { readFile, writeFile, ensureDir, copy } from "fs-extra";
 import { createVSCodeCommandManager } from "../../../src/common/vscode/commands";
 import type { AllCommands } from "../../../src/common/commands";
+import { getActivatedExtension } from "../global.helper";
 
 /**
  * Integration tests for queries
  */
 describe("SourceMap", () => {
   const commandManager = createVSCodeCommandManager<AllCommands>();
 
+  beforeEach(async () => {
+    // Ensure that the extension is fully activated before running tests. This is important
+    // because the extension activate() function ensures that the language server is up and
+    // running before returning, so that we don't get "Client is not running" test flakes.
+    await getActivatedExtension();
+  });
+
   it("should jump to QL code", async () => {
     const root = workspace.workspaceFolders![0].uri.fsPath;
     const srcFiles = {