pretty: test --expand-tabs

The test prepares a simple commit with HT on its log message lines,
and makes sure that

- formats that should or should not expand tabs by default do or do
not expand tabs respectively,

- with explicit --expand-tabs=<N> and short-hands --expand-tabs
(equivalent to --expand-tabs=8) and --no-expand-tabs (equivalent
to --expand-tabs=0) before or after the explicit --pretty=$fmt,
the tabs are expanded (or not expanded) accordingly.

The tests use the second line of the log message for formats other
than --pretty=short, primarily because the first line of the email
format is handled specially to add the [PATCH] prefix, etc. in a
separate codepath (--pretty=short uses the first line because there
is no other line to test).

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t4213-log-tabexpand.sh b/t/t4213-log-tabexpand.sh
new file mode 100755 (executable)
index 0000000..e01a8f6
--- /dev/null
+++ b/t/t4213-log-tabexpand.sh
@@ -0,0 +1,105 @@
+#!/bin/sh
+
+test_description='log/show --expand-tabs'
+
+. ./test-lib.sh
+
+HT="   "
+title='tab indent at the beginning of the title line'
+body='tab indent on a line in the body'
+
+# usage: count_expand $indent $numSP $numHT @format_args
+count_expand ()
+{
+       expect=
+       count=$(( $1 + $2 )) ;# expected spaces
+       while test $count -gt 0
+       do
+               expect="$expect "
+               count=$(( $count - 1 ))
+       done
+       shift 2
+       count=$1 ;# expected tabs
+       while test $count -gt 0
+       do
+               expect="$expect$HT"
+               count=$(( $count - 1 ))
+       done
+       shift
+
+       # The remainder of the command line is "git show -s" options
+       case " $* " in
+       *' --pretty=short '*)
+               line=$title ;;
+       *)
+               line=$body ;;
+       esac
+
+       # Prefix the output with the command line arguments, and
+       # replace SP with a dot both in the expecte and actual output
+       # so that test_cmp would show the differene together with the
+       # breakage in a way easier to consume by the debugging user.
+       {
+               echo "git show -s $*"
+               echo "$expect$line"
+       } | sed -e 's/ /./g' >expect
+
+       {
+               echo "git show -s $*"
+               git show -s "$@" |
+               sed -n -e "/$line\$/p"
+       } | sed -e 's/ /./g' >actual
+
+       test_cmp expect actual
+}
+
+test_expand ()
+{
+       fmt=$1
+       case "$fmt" in
+       *=raw | *=short | *=email)
+               default="0 1" ;;
+       *)
+               default="8 0" ;;
+       esac
+       case "$fmt" in
+       *=email)
+               in=0 ;;
+       *)
+               in=4 ;;
+       esac
+       test_expect_success "expand/no-expand${fmt:+ for $fmt}" '
+               count_expand $in $default $fmt &&
+               count_expand $in 8 0 $fmt --expand-tabs &&
+               count_expand $in 8 0 --expand-tabs $fmt &&
+               count_expand $in 8 0 $fmt --expand-tabs=8 &&
+               count_expand $in 8 0 --expand-tabs=8 $fmt &&
+               count_expand $in 0 1 $fmt --no-expand-tabs &&
+               count_expand $in 0 1 --no-expand-tabs $fmt &&
+               count_expand $in 0 1 $fmt --expand-tabs=0 &&
+               count_expand $in 0 1 --expand-tabs=0 $fmt &&
+               count_expand $in 4 0 $fmt --expand-tabs=4 &&
+               count_expand $in 4 0 --expand-tabs=4 $fmt
+       '
+}
+
+test_expect_success 'setup' '
+       test_tick &&
+       sed -e "s/Q/$HT/g" <<-EOF >msg &&
+       Q$title
+
+       Q$body
+       EOF
+       git commit --allow-empty -F msg
+'
+
+test_expand ""
+test_expand --pretty
+test_expand --pretty=short
+test_expand --pretty=medium
+test_expand --pretty=full
+test_expand --pretty=fuller
+test_expand --pretty=raw
+test_expand --pretty=email
+
+test_done