From 187ed5f3ddd067c08a16650d83d02f55a020e660 Mon Sep 17 00:00:00 2001
From: Joe Wallwork <jw2423@cam.ac.uk>
Date: Mon, 18 Nov 2024 13:22:29 +0000
Subject: [PATCH 1/2] Compare git diff before and after formatting loop

---
 .pre-commit | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.pre-commit b/.pre-commit
index 551a1d9e3..f47b71507 100644
--- a/.pre-commit
+++ b/.pre-commit
@@ -2,6 +2,8 @@
 
 # An example pre-commit file for nextSIM-DG development
 
+git diff >nextsim_precommit_before.patch
+
 for FILE in $(git diff --cached --name-only | grep -iE '\.(cpp|cc|h|hpp)$'); do
   # Apply clang-format for linting
   clang-format -i ${FILE} --verbose
@@ -11,3 +13,10 @@ for FILE in $(git diff --cached --name-only | grep -iE '\.(cpp|cc|h|hpp)$'); do
   NEWLINE=$(printf "%s%$((SPACES))s%s\n" " @date" " " "$(date '+%d %b %Y')")
   sed -i~ "s/${LINE}/${NEWLINE}/" ${FILE}
 done
+
+# Abort commit if formatting was applied
+git diff >nextsim_precommit_after.patch
+if [ "$(diff nextsim_precommit_before.patch nextsim_precommit_after.patch)" ]; then
+  echo "Aborting git commit because the pre-commit hook made changes."
+  exit 1
+fi

From 68569459df372e61db68d5a3b8649417ba880d0c Mon Sep 17 00:00:00 2001
From: Joe Wallwork <22053413+jwallwork23@users.noreply.github.com>
Date: Fri, 22 Nov 2024 13:40:23 +0000
Subject: [PATCH 2/2] Apply suggestions from @einola
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Einar Örn Ólason <einar.olason@nersc.no>
---
 .pre-commit | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/.pre-commit b/.pre-commit
index f47b71507..55bdc4b1f 100644
--- a/.pre-commit
+++ b/.pre-commit
@@ -2,7 +2,8 @@
 
 # An example pre-commit file for nextSIM-DG development
 
-git diff >nextsim_precommit_before.patch
+BEFORE=$(mktemp)
+git diff > ${BEFORE}
 
 for FILE in $(git diff --cached --name-only | grep -iE '\.(cpp|cc|h|hpp)$'); do
   # Apply clang-format for linting
@@ -15,8 +16,10 @@ for FILE in $(git diff --cached --name-only | grep -iE '\.(cpp|cc|h|hpp)$'); do
 done
 
 # Abort commit if formatting was applied
-git diff >nextsim_precommit_after.patch
+AFTER=$(mktemp)
+git diff > ${AFTER}
 if [ "$(diff nextsim_precommit_before.patch nextsim_precommit_after.patch)" ]; then
   echo "Aborting git commit because the pre-commit hook made changes."
+  rm ${BEFORE} ${AFTER}
   exit 1
 fi