Re: [PATCH v2 12/27] userdiff tests: rewrite hunk header test infrastructure

> Rewrite the hunk header test infrastructure introduced in
> bfa7d01413 (t4018: an infrastructure to test hunk headers,
> 2014-03-21). See c228a5c077 (Merge branch 'js/userdiff-cc',
> 2014-03-31) for the whole series that commit was part of.
> 
> As noted in an earlier commit that change introduced the regression of
> not testing for the full hunk line, but just whether "RIGHT" appeared
> on it[1]. A preceding commit fixed that specific issue, but we were
> still left with the inflexibility of the approach described in the
> now-deleted t/t4018/README.
> 
> I.e. to add any sort of new tests that used the existing test data
> we'd either need to add more files like the recently added (but now
> deleted) *.ctx) files, using the filesystem as our test datastructure,
> or introduce more parsing for the custom file format we were growing
> here.
> 
> Let's instead just move this over to using a custom test
> function. This makes it trivial to add new tests by adding new
> optional parameters to the function. Let's still keep the relevant
> files in the "t/t4018/" subdirectory instead of adding ~1.5k
> lines (and growing) to "t/t4018-diff-funcname.sh"
> 
> If this diff is viewed with "--color-moved=plain" we can see that
> there's no changes to the lines being moved into the new *.sh files,
> i.e. all the deletions are moves. I'm just adding boilerplate around
> those existing lines.
> 
> The one-off refactoring was performed by an ad-hoc shellscript [2].
> 
> 1. https://lore.kernel.org/git/87wnvbbf2y.fsf@evledraar.gmail.com/
> 2.
> 	#!/bin/sh
> 	set -ex
> 
> 	git rm README*
> 	for t in $(git ls-files ':!*.ctx')
> 	do
> 		lang=$(echo $t | sed 's/-.*//')
> 		desc=$(echo $t | sed -E 's/^[^-]*-//' | tr - " ")
> 
> 		if ! test -e $lang.sh
> 		then
> 			cat >$lang.sh <<-EOF
> 			#!/bin/sh
> 			#
> 			# See ../t4018-diff-funcname.sh's test_diff_funcname()
> 			#
> 
> 			EOF
> 		else
> 			echo >>$lang.sh
> 	        fi
> 
> 		(
> 	            printf "test_diff_funcname '%s: %s' \\" "$lang" "$desc"
> 	            echo
> 	            printf "\t8<<%sEOF_HUNK 9<<%sEOF_TEST\n" '\' '\'
> 	            cat $t.ctx
> 	            printf "EOF_HUNK\n"
> 	            cat $t
> 	            printf "EOF_TEST\n"
> 		) >>$lang.sh
> 
> 		chmod +x $lang.sh
> 		git add $lang.sh
> 	        git rm $t $t.ctx
> 	done
> 
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---

> diff --git a/t/t4018/bash.sh b/t/t4018/bash.sh
> new file mode 100755
> index 0000000000..69144d9144
> --- /dev/null
> +++ b/t/t4018/bash.sh
> @@ -0,0 +1,160 @@
> +#!/bin/sh
> +#
> +# See ../t4018-diff-funcname.sh's test_diff_funcname()
> +#
> +
> +test_diff_funcname 'bash: arithmetic function' \
> +	8<<\EOF_HUNK 9<<\EOF_TEST
> +RIGHT()
> +EOF_HUNK
> +RIGHT() ((
> +
> +    ChangeMe = "$x" + "$y"
> +))
> +EOF_TEST
> +
> +test_diff_funcname 'bash: bashism style compact' \
> +	8<<\EOF_HUNK 9<<\EOF_TEST
> +function RIGHT {
> +EOF_HUNK
> +function RIGHT {
> +    function InvalidSyntax{
> +        :
> +        echo 'ChangeMe'
> +    }
> +}
> +EOF_TEST
> +
> +test_diff_funcname 'bash: bashism style function' \
> +	8<<\EOF_HUNK 9<<\EOF_TEST
> +function RIGHT {
> +EOF_HUNK
> +function RIGHT {
> +    :
> +    echo 'ChangeMe'
> +}
> +EOF_TEST
> [...]