REPL outputs 'use strict' after first empty line of input

[cspotcode]

Expected Behavior

If you type nothing into the first line of REPL input, you should not see 'use strict'. The TS compiler emits 'use strict' but that's not what the user entered, so they shouldn't see it.

Actual Behavior

Hitting enter in the REPL with no input on the first line shows use strict