On 2020-03-19 12:33:34-0400, Jeff King <peff@xxxxxxxx> wrote:
> On Thu, Mar 19, 2020 at 09:00:07PM +0700, Đoàn Trần Công Danh wrote:
>
> > POSIX's diff(1) requires output in normal diff format.
> > However, busybox's diff's output is written in unified format.
>
> That's a pretty big difference. I'm surprised this only produces one
> problem in the test scripts. ;)
>
> > POSIX requires no option for normal-diff format.
> >
> > A hint in test-lib-functions::test_cmp said `diff -u` isn't available
> > everywhere.
> >
> > Workaround this problem by assuming `diff(1)` output is unified
> > if we couldn't make anything from normal-diff format.
>
> I wonder if we could use "git diff" here. We have to be careful about
> circular reasoning in our tests (i.e., making sure we're not verifying
> output with the same code that we're testing), but I think here we're
> checking how "apply --whitespace=fix" works.
>
> But if this is the only spot, then adjusting to handle unified or normal
> diff isn't too bad.
>
> > diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
> > index 971a5a7512..2a54ce96b5 100755
> > --- a/t/t4124-apply-ws-rule.sh
> > +++ b/t/t4124-apply-ws-rule.sh
> > @@ -52,6 +52,12 @@ test_fix () {
> >
> > # find touched lines
> > $DIFF file target | sed -n -e "s/^> //p" >fixed
> > + if ! test -s fixed; then
> > + $DIFF file target |
> > + grep '^+' |
> > + grep -v '^+++' |
> > + sed -e "s/+//" >fixed
> > + fi
>
> I think those greps could be lumped into sed like:
>
> sed -ne "s/^+[^+]//p"
>
> (at the cost of missing blank lines, but I think that's OK for our
> purposes here; it could be fixed with an ERE).
>
> Could we then make a single invocation that covers both diff formats? We
> can further observe that the only thing we do with the "fixed" file is
> count the lines, so we can leave the markers. Which means we could ditch
> sed entirely and use grep. Something like:
>
> diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
> index 971a5a7512..15cb0c81b7 100755
> --- a/t/t4124-apply-ws-rule.sh
> +++ b/t/t4124-apply-ws-rule.sh
> @@ -50,8 +50,9 @@ test_fix () {
> # fix should not barf
> apply_patch --whitespace=fix || return 1
>
> - # find touched lines
> - $DIFF file target | sed -n -e "s/^> //p" >fixed
> + # find touched lines; handle either normal or unified
> + # diff, as system diff may generate either
> + $DIFF file target | grep '^[>+][^+]' >fixed
>
> # the changed lines are all expected to change
> fixed_cnt=$(wc -l <fixed)
>
> seems to work for with both busybox diff and GNU diff.
3 lines after this one:
?*) expect_cnt=$(grep "[$1]" <fixed | wc -l) ;;
As of now, we could simply replace sed with grep entirely,
because ! "$1" ~"[>+]".
Considering the complicated of:
test_expect_success "rule=$rule" '
git config core.whitespace "$rule" &&
test_fix "$tt$ts$ti$th"
'
I think it's better to use sed here.
--
Danh
