Watch a small directory for testing purposes (#4385)

Author: mattseddon

extension/src/test/suite/setup/util.ts

@@ -162,6 +162,7 @@ export const buildSetupWithWatchers = async (disposer: Disposer) => {
   ensureDirSync(TEMP_DIR)
 
   stub(WorkspaceFolders, 'getFirstWorkspaceFolder').returns(TEMP_DIR)
+  stub(WorkspaceFolders, 'getWorkspaceFolders').returns([TEMP_DIR])
 
   const setup = disposer.track(
     new Setup(