Adjust pre-commit script to readd files after formatting

Author: xFrednet

util/etc/pre-commit.sh

@@ -1,3 +1,21 @@
 #!/bin/sh
 
-cargo dev fmt
+# hide output
+set -e
+
+# Update lints
+cargo dev update_lints
+git add clippy_lints/src/lib.rs
+
+# Formatting:
+#     Git will not automatically add the formatted code to the staged changes once
+#     fmt was executed. This collects all staged files rs files that are currently staged.
+#     They will later be added back.
+#
+#     This was proudly stolen and adjusted from here:
+#     https://medium.com/@harshitbangar/automatic-code-formatting-with-git-66c3c5c26798
+files=$( (git diff --cached --name-only --diff-filter=ACMR | grep -Ei "\.rs$") || true)
+if [ ! -z "${files}" ]; then
+    cargo dev fmt
+    git add $(echo "$files" | paste -s -d " " -)
+fi