Actions workflow to format code on command (#5400)

* Add script to perform or check formatting

* Actions workflow to format code on command

Comment on a PR with /format

1 files changed, 81 insertions, 0 deletions

diff --git a/extras/formatting.sh b/extras/formatting.sh
new file mode 100755
index 000000000..dc3bbc7ca
--- /dev/null
+++ b/extras/formatting.sh
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
+cd "$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel)" || exit 1
+
+check_only=0
+
+while [[ "$#" -gt 0 ]]; do
+  case $1 in
+  -h | --help) help=1 ;;
+  --check-only) check_only=1 ;;
+  esac
+  shift
+done
+
+if [ "$help" ]; then
+  me=$(basename "$0")
+  cat <<EOF
+$me: Format or check formatting of files in this repo
+
+Usage: $me [--check-only]
+
+Options:
+    --check-only     Check formatting without modifying files
+EOF
+  exit 0
+fi
+
+require_bin() {
+  local name="$1"
+  local required="$2"
+  local version
+
+  if ! command -v "$name" &>/dev/null; then
+    echo "This script needs $name, but it isn't in \$PATH"
+    missing_bin=1
+    return
+  fi
+
+  version=$("$name" --version | grep -oP "$name(?:\s+version)?\s+\K\d+\.\d+\.?\d*")
+  if ! printf '%s\n%s\n' "$required" "$version" | sort -V -C; then
+    echo "$name version $version is too old. Version $required or newer is required."
+    missing_bin=1
+  fi
+}
+
+require_bin "git" "1.8"
+require_bin "gersemi" "0.16.2"
+
+if [ "${missing_bin:-}" = "1" ]; then
+  exit 1
+fi
+
+if [ "$missing_bin" ]; then
+  exit 1
+fi
+
+exit_code=0
+
+cmake_formatting() {
+  readarray -t files < <(git ls-files '*.cmake' 'CMakeLists.txt' '**/CMakeLists.txt')
+
+  common_args=(
+    # turn on warning when this is fixed https://github.com/BlankSpruce/gersemi/issues/39
+    --no-warn-about-unknown-commands
+    --definitions "${files[@]}"
+  )
+
+  if [ "$check_only" -eq 1 ]; then
+    gersemi "${common_args[@]}" --diff --color "${files[@]}"
+    gersemi "${common_args[@]}" --check "${files[@]}" || exit_code=1
+  else
+    gersemi "${common_args[@]}" --in-place "${files[@]}"
+  fi
+}
+
+cmake_formatting
+
+exit $exit_code