This will clear the unversioned out directory - useful to get rid of files after renaming or deleting TS files. This will keep any hidden directories like .vscode-test which has a large binary for integration tests.
$ npm run cleanA few problems have been resolved by running the clean command, so this is now part of the build step so it runs every time when doing tests or running the extension. Note that the build/compile step happens as part of watch too, so it is covered there.