sstephensonGH-184: Fix link resolution for bats

This rewrites the old logic a bit by using `type -p`, `readlink -m`  and
on boxes where we don't have coreutils like `readlink` we use `realpath`
to figure out the correct installation directory of bats.

Also fixes GH#182

Signed-off-by: Wesley Schwengle <wesley@schwengle.net>

bin/bats

@@ -3,42 +3,71 @@
 set -e
 
 BATS_READLINK='true'
+BATS_REALPATH=''
 if command -v 'greadlink' >/dev/null; then
   BATS_READLINK='greadlink'
 elif command -v 'readlink' >/dev/null; then
   BATS_READLINK='readlink'
 fi
 
-bats_resolve_absolute_root_dir() {
-  local cwd="$PWD"
-  local path="$1"
-  local result="$2"
-  local target_dir
-  local target_name
-  local original_shell_options="$-"
-
-  # Resolve the parent directory, e.g. /bin => /usr/bin on CentOS (#113).
-  set -P
+set +e
+if ! $BATS_READLINK -m $0 &>/dev/null; then
+  BATS_REALPATH='realpath'
+fi
+set -e
 
-  while true; do
-    target_dir="${path%/*}"
-    target_name="${path##*/}"
+resolve_path() {
+  local path_to_bats=$1
+  local target_path;
 
-    if [[ "$target_dir" != "$path" ]]; then
-      cd "$target_dir"
+  if [[ -L "$path_to_bats" ]]; then
+    # Busybox has no readlink from coreutils
+    if [[ ! -z "$BATS_REALPATH" ]]; then
+      target_path="$("$BATS_REALPATH" "$path_to_bats")"
+      # we need to traverse the paths
+      target_path="$(dirname "$target_path")" # strip bats
+      target_path="$(dirname "$target_path")" # strip bin
+    else
+      target_path="$("$BATS_READLINK" -m "$path_to_bats/../../")"
     fi
-
-    if [[ -L "$target_name" ]]; then
-      path="$("$BATS_READLINK" "$target_name")"
+  elif [[ -f "$path_to_bats" ]]; then
+    target_path=$(dirname "$path_to_bats");
+    if [[ ! -z "$BATS_REALPATH" ]]; then
+      target_path="$("$BATS_REALPATH" "$target_path")"
+    else
+      target_path="$("$BATS_READLINK" -m "$target_path")"
+    fi
+    target_path="$(dirname "$target_path")" # strip bin
+  elif [[ -d $path_to_bats ]]; then
+    if [[ ! -z "$BATS_REALPATH" ]]; then
+      target_path="$("$BATS_REALPATH" "$path_to_bats")"
+      target_path="$(dirname "$target_path")"
     else
-      printf -v "$result" -- '%s' "${PWD%/*}"
-      set +P "-$original_shell_options"
-      cd "$cwd"
-      return
+      target_path="$("$BATS_READLINK" -m "$path_to_bats/../")"
     fi
-  done
+  fi
+
+  echo "$target_path";
+}
+
+bats_resolve_absolute_root_dir() {
+  local cwd="$PWD"
+  local path_to_bats="$1"
+  local result="$2"
+  local target_path
+
+  if [[ "$path_to_bats" = $(basename $1) ]] ; then
+    path_to_bats=$(type -p "$path_to_bats")
+  fi
+
+  target_path="$(resolve_path $path_to_bats)"
+  if [[ "$target_path" == '.' ]];
+  then
+    target_path="$(resolve_path "$target_path")"
+  fi
+  printf -v "$result" -- '%s' "$target_path"
 }
 
 export BATS_ROOT
 bats_resolve_absolute_root_dir "$0" 'BATS_ROOT'
-exec "$BATS_ROOT/libexec/bats-core/bats" "$@"
+exec env BATS_ROOT="$BATS_ROOT" "$BATS_ROOT/libexec/bats-core/bats" "$@"

test/root.bats

@@ -40,28 +40,52 @@ setup() {
 
 # The resolution scheme here is:
 #
+# Set in setup
 # - /bin => /usr/bin (relative directory)
-# - /usr/bin/foo => /usr/bin/bar (relative executable)
-# - /usr/bin/bar => /opt/bats/bin0/bar (absolute executable)
-# - /opt/bats/bin0 => /opt/bats/bin1 (relative directory)
-# - /opt/bats/bin1 => /opt/bats/bin2 (absolute directory)
-# - /opt/bats/bin2/bar => /opt/bats-core/bin/bar (absolute executable)
-# - /opt/bats-core/bin/bar => /opt/bats-core/bin/baz (relative executable)
-# - /opt/bats-core/bin/baz => /opt/bats-core/bin/bats (relative executable)
 @test "set BATS_ROOT with extreme symlink resolution" {
   cd "$BATS_TEST_SUITE_TMPDIR"
   mkdir -p "opt/bats/bin2"
 
+# - /usr/bin/foo => /usr/bin/bar (relative executable)
   ln -s bar usr/bin/foo
+# - /usr/bin/bar => /opt/bats/bin0/bar (absolute executable)
   ln -s "$BATS_TEST_SUITE_TMPDIR/opt/bats/bin0/bar" usr/bin/bar
+# - /opt/bats/bin0 => /opt/bats/bin1 (relative directory)
   ln -s bin1 opt/bats/bin0
+# - /opt/bats/bin1 => /opt/bats/bin2 (absolute directory)
   ln -s "$BATS_TEST_SUITE_TMPDIR/opt/bats/bin2" opt/bats/bin1
+# - /opt/bats/bin2/bar => /opt/bats-core/bin/bar (absolute executable)
   ln -s "$BATS_TEST_SUITE_TMPDIR/opt/bats-core/bin/bar" opt/bats/bin2/bar
+# - /opt/bats-core/bin/bar => /opt/bats-core/bin/baz (relative executable)
   ln -s baz opt/bats-core/bin/bar
+# - /opt/bats-core/bin/baz => /opt/bats-core/bin/bats (relative executable)
   ln -s bats opt/bats-core/bin/baz
 
   cd - >/dev/null
   run "$BATS_TEST_SUITE_TMPDIR/bin/foo" -v
   [ "$status" -eq 0 ]
   [ "${output%% *}" == 'Bats' ]
 }
+
+@test "set BATS_ROOT when calling from same dir" {
+  cd "$BATS_TEST_SUITE_TMPDIR"
+  run ./bin/bats -v
+  [ "$status" -eq 0 ]
+  [ "${output%% *}" == 'Bats' ]
+}
+
+@test "set BATS_ROOT from PATH" {
+  cd /tmp
+  PATH="$PATH:$BATS_TEST_SUITE_TMPDIR/bin"
+  run bats -v
+  [ "$status" -eq 0 ]
+  [ "${output%% *}" == 'Bats' ]
+}
+
+@test "#182 and probably #184 as well" {
+  cd /tmp
+  PATH="$PATH:$BATS_TEST_SUITE_TMPDIR/bin"
+  run bash bats -v
+  [ "$status" -eq 0 ]
+  [ "${output%% *}" == 'Bats' ]
+}