Extract `alias_write_to_file` test function contents to helper

Create a new helper function that does the work of
`alias_write_to_file_must_write_given_alias_to_file`. We want to be able
to add another test of the `write_to_file` method that does the same
thing but for non-preexisting aliases. Making a helper method will allow
us to avoid duplicating work.

0 files changed, 0 insertions, 0 deletions