Make test work on windows (hopfully) and fix interface

Author: fkling

agent/src/vscode-shim.ts

@@ -344,7 +344,11 @@ const _workspace: typeof vscode.workspace = {
                   )
               )
     },
-    workspaceFolders,
+    get workspaceFolders() {
+        // According to the docs, workspaceFolders is `undefined` when no
+        // workspace has been opened.
+        return workspaceFolders.length === 0 ? undefined : workspaceFolders
+    },
     getWorkspaceFolder: (uri: vscode.Uri) => {
         for (const folder of workspaceFolders) {
             if (uriHasPrefix(uri, folder.uri, isWindows())) {

lib/shared/vitest.config.ts

@@ -4,5 +4,8 @@ export default defineProjectWithDefaults(__dirname, {
     test: {
         environment: 'jsdom', // needed for DOMPurify
         setupFiles: ['src/test/testSetup.ts'],
+        env: {
+            CODY_SHIM_TESTING: 'true',
+        },
     },
 })