Aliases are expanded in parameters position and it depends on space in alias definition:


$ echo $BASH_VERSION
5.0.18(2)-release
$ unalias ls
$ alias t=/bin/true
$ ls t
ls: cannot access 't': No such file or directory
$ alias ls=ls
$ ls t
ls: cannot access 't': No such file or directory
$ alias ls='ls '
$ ls t
/bin/true
$ alias ls='ls -l'
$ ls t
ls: cannot access 't': No such file or directory
$ alias ls='ls -l '
$ ls t
-rwxr-xr-x 1 root root 31128 Mar  6  2020 /bin/true