[githooks] Refactor/rename check-style; NFC

It sounds like we want to start using check-style as part of a test
runner. Refactoring check-style a bit allows us to trivially do that
cleanly in parallel with code style/lint checks.

No functional change is intended.

BUG=None
TEST=repo upload

Change-Id: I1fea43922dd37e571b7d2695656f480d5b458460
Reviewed-on: https://chromium-review.googlesource.com/1516417
Commit-Ready: George Burgess <gbiv@chromium.org>
Tested-by: George Burgess <gbiv@chromium.org>
Reviewed-by: Luis Lozano <llozano@chromium.org>

1 files changed, 25 insertions, 24 deletions

diff --git a/toolchain_utils_githooks/check-style b/toolchain_utils_githooks/check-style
index 0ce11877..fa06fa3e 100755
--- a/toolchain_utils_githooks/check-style
+++ b/toolchain_utils_githooks/check-style
@@ -3,8 +3,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
-# Convenient wrapper to run format and lint checks in parallel without
-# interleaving output/etc.
+# Convenient wrapper to run presubmit checks in parallel without interleaving
+# output/etc.
 
 if [[ $# -eq 0 ]]; then
   echo "No files were given to check the style of. Exiting." >&2
@@ -13,31 +13,32 @@ fi
 
 mydir="$(dirname "$(readlink -m "$0")")"
 
-tempfile="$(mktemp)"
-rm_tempfile() {
-  rm -f "${tempfile}"
+tempfiles=()
+rm_tempfiles() {
+  rm -f "${tempfiles[@]}"
 }
 
-trap rm_tempfile EXIT
+trap rm_tempfiles EXIT
 
-success=true
+child_pids=()
+spawn_child() {
+  local tempfile
+  tempfile="$(mktemp)"
+  tempfiles+=( "${tempfile}" )
+  "$@" >"${tempfile}" 2>&1 &
+  child_pids+=( "$!" )
+}
 
-# Since we only have two things to do in parallel, we just output the
-# stdout/stderr of this to a temp file. When the other check is done, we `cat`
-# the temp file, and we're good.
-#
-# It appears that check-lint will emit colorful output regardless of whether or
-# not it's writing to a tty, so we don't lose the nice red "ERROR" text from
-# it.
-"${mydir}/check-lint" "$@" >"${tempfile}" 2>&1 &
-pid="$!"
-
-"${mydir}/check-format" "$@" || success=false
-wait "${pid}" || success=false
-
-lint_output="$(cat "${tempfile}")"
-if [[ -n "${lint_output}" ]]; then
-  echo "${lint_output}"
-fi
+# We have a few things to do in parallel here. To avoid interleaving their
+# output, we pipe them all to tempfiles, then cat those tempfiles.
+
+spawn_child "${mydir}/check-lint" "$@"
+spawn_child "${mydir}/check-format" "$@"
+
+success=true
+for i in "${!child_pids[@]}"; do
+  wait "${child_pids[$i]}" || success=false
+  cat "${tempfiles[$i]}"
+done
 
 "${success}"