Character by Character Your program must take in a string like:

test string


And must output each character adding one at a time like this:

t
te
tes
test
test 
test s
test st
test str
test stri
test strin
test string


notice how spaces count!

Good luck!
Least Bytes win.
~N
05AB1E, 3 bytes

Uses CP-1252 encoding.

.p»


Try it online!

Explanation

     # implicit input
.p   # list of prefixes
  »  # join by newlines