Git hook to prevent unformatted code from being committed

.gitignore

@@ -150,6 +150,9 @@ src/config
 # codespell dictionary
 scripts/dictionary/
 
+# time marker for pre-commit hook to check if staged files have been formatted
+scripts/.last_format_time
+
 # clangd for nvim lsp
 src/.clangd
 

environment_setup/setup_software.sh

@@ -18,6 +18,8 @@
 CURR_DIR=$(dirname -- "$(readlink -f -- "$BASH_SOURCE")")
 cd "$CURR_DIR" || exit
 
+git config core.hooksPath "$CURR_DIR/../scripts/githooks"
+
 source util.sh
 
 g_arch=$(uname -m)  # Global variable. No function should use this name.

scripts/githooks/pre-commit

@@ -0,0 +1,16 @@
+#!/bin/sh
+
+filter_formattable_files() {
+    grep -E '\.(h|cpp|c|cc|hpp|tpp|proto|py|md|yml)$|/BUILD$'
+}
+
+toplevel="$(git rev-parse --show-toplevel)"
+mtime=$(stat -c %Y "$toplevel/scripts/.last_format_time" 2> /dev/null || echo 0)
+
+git diff --staged --name-only | filter_formattable_files | while read -r file; do
+    if [ $mtime -lt "$(stat -c %Y "$toplevel/$file")" ]; then
+        # last format invocation was before staged changes
+        echo "Please run $toplevel/scripts/lint_and_format.sh before committing!" 1>&2
+        exit 1
+    fi
+done

scripts/lint_and_format.sh

@@ -149,4 +149,7 @@ run_eof_new_line
 run_git_diff_check
 run_ansible_lint
 
+# Update time marker so pre-commit git hook knows that code has been formatted
+touch "$CURR_DIR/.last_format_time"
+
 exit 0