From daf76c27c146598c2deba15694c6cd01b2cd82a6 Mon Sep 17 00:00:00 2001
From: Mike Bland <mbland@acm.org>
Date: Thu, 16 Mar 2017 12:25:17 -0400
Subject: [PATCH] bats: Convert abs_dirname to use `printf -v`

Under Bash 3.2.57(1)-release and 4.4.12(1)-release on a MacBook Pro with
a 2.9GHz Intel Core i5 CPU and 8GB 1867MHz DDR3 RAM, this shaves off
O(0.1s) from the current test suite.

Before the change:

  46 tests, 0 failures

  real    0m3.983s
  user    0m2.320s
  sys     0m1.241s

After the change:

  real    0m3.861s
  user    0m2.276s
  sys     0m1.174s
---
 libexec/bats | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/libexec/bats b/libexec/bats
index 8129050..5e90a9e 100755
--- a/libexec/bats
+++ b/libexec/bats
@@ -51,7 +51,7 @@ abs_dirname() {
     path="$(resolve_link "$name")"
   done
 
-  pwd
+  printf -v "$2" -- '%s' "$PWD"
   cd "$cwd"
 }
 
@@ -63,9 +63,12 @@ expand_path() {
   } || echo "$1"
 }
 
-BATS_LIBEXEC="$(abs_dirname "$0")"
-export BATS_PREFIX="$(abs_dirname "$BATS_LIBEXEC")"
-export BATS_CWD="$(abs_dirname .)"
+abs_dirname "$0" 'BATS_LIBEXEC'
+abs_dirname "$BATS_LIBEXEC" 'BATS_PREFIX'
+abs_dirname '.' 'BATS_CWD'
+
+export BATS_PREFIX
+export BATS_CWD
 export PATH="$BATS_LIBEXEC:$PATH"
 
 options=()