run
focus
insert "hello\nworld"
key up
key ctrl+a
----
-- view:
┃  1 [7mh[0mello                              ␤
┃  2 world                              ␤
┃  ~                                    ␤
┃  ~                                    ␤
┃  ~                                    ␤
┃  ~                                    🛇

# Enter overwrite mode then type over.
run observe=(view,value)
key alt+o
type un
----
-- view:
┃  1 un[7ml[0mlo                              ␤
┃  2 world                              ␤
┃  ~                                    ␤
┃  ~                                    ␤
┃  ~                                    ␤
┃  ~                                    🛇
-- value:
"unllo\nworld"

# Overwrite past end of line remains on the same line.
run observe=(view,value)
type iverse
----
-- view:
┃  1 universe[7m [0m                          ␤
┃  2 world                              ␤
┃  ~                                    ␤
┃  ~                                    ␤
┃  ~                                    ␤
┃  ~                                    🛇
-- value:
"universe\nworld"
