On Wed, Apr 21, 2021 at 12:55 PM Eric Sunshine [off-list ref] wrote:

    count_ls_files 5 -s &&
    count_ls_files 3 -u &&
    count_ls_files 1 -u one~HEAD &&
    ...

The nice thing about having a helper function is that it can clean up
after itself by not leaving a new file lying around, thus you wouldn't
have to make adjustments to the expected number of untracked files (as
mentioned in the commit message). If this is the sort of thing which
comes up often enough (if there are more such cases beyond the two
scripts you changed in this series), then it might make sense to
promote the helper function to test-lib-functions.sh.

The frequency with which this idiom crops up with commands beyond
git-ls-files suggests the more general solution of supporting it
directly in test-lib-functions.sh for any command. For instance:

    test_cmd_line_count = 3 git ls-files -u &&

Or, perhaps, a new mode of test_line_count():

    test_line_count = 3 -c git ls-files -u &&