use native terminal-drawing character

Author: lamchau

diff-so-fancy

@@ -62,7 +62,11 @@ strip_first_column () {
 }
 
 print_horizontal_rule () {
-  printf "%$(tput cols)s\n"| $SED 's/ /─/g'
+  let width="$(tput cols)"
+
+  # echo -n '─' | hexdump -C
+  local -r dash=$( printf "%b" "\xe2\x94\x80" )
+  printf "%*s\n" "$width" | $SED "s/ /${dash}/g"
 }
 
 print_header_clean () {

test/diff-so-fancy.bats

@@ -43,3 +43,11 @@ if begin"
   output=$( load_fixture "noprefix" | $diff_so_fancy )
   refute_output --partial "diff --git setup-a-new-machine.sh"
 }
+
+@test "header format uses a native line-drawing character" {
+  header=$( printf "%s" "$output" | head -n3 )
+  run printf "%s" "$header"
+  assert_line --index 0 --partial "─────"
+  assert_line --index 1 --partial "modified: fish/functions/ls.fish"
+  assert_line --index 2 --partial "─────"
+}