switch to pre-commit

.github/scripts/clang-format-hook

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+# Thin wrapper around clang-format for easier to parse output from the
+# pre-commit hook.
+#
+# Needs to work with multiple input files as pre-commit passes multiple files to
+# the "executables"
+
+# Make sure that diff is actually recent enough (diffutils >= 3.4) to support
+# colored output
+COLOR_OUTPUT=$(diff --color=always <(echo) <(echo) > /dev/null 2>&1 && echo "--color=always")
+
+success=0
+for file in ${@}; do
+    if ! $(clang-format --style=file --Werror --dry-run ${file} > /dev/null 2>&1); then
+        echo "Necessary changes for: '${file}' (run 'clang-format --style=file -i ${file}' to fix it)"
+        diff ${COLOR_OUTPUT} -u ${file} <(clang-format --style=file ${file}) | tail -n +3
+        success=1
+    fi
+done
+exit ${success}

.github/templates/apache-2.tmpl

@@ -0,0 +1,16 @@
+Copyright (c) ${years} ${owner}.
+
+This file is part of ${projectname}.
+See ${projecturl} for further info.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

.github/workflows/pre-commit.yml

@@ -0,0 +1,23 @@
+name: pre-commit
+
+on: [push, pull_request]
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: cvmfs-contrib/[email protected]
+    - uses: aidasoft/run-lcg-view@v4
+      with:
+        release-platform: LCG_101/x86_64-centos7-clang12-opt
+        run: |
+          export PYTHONPATH=$(python -m site --user-site):$PYTHONPATH
+          export PATH=/root/.local/bin:$PATH
+          pip install --upgrade --user pip
+          pip install pre-commit --user
+          # Use virtualenv from the LCG release
+          pip uninstall --yes virtualenv
+          pre-commit run --show-diff-on-failure \
+            --color=always \
+            --all-files

.pre-commit-config.yaml

@@ -0,0 +1,25 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v3.4.0
+    hooks:
+      - id: mixed-line-ending
+      - id: trailing-whitespace
+        exclude: (doc/ReleaseNotes.md)
+  - repo: local
+    hooks:
+      - id: clang-format
+        name: clang-format
+        entry: .github/scripts/clang-format-hook
+        types: [c++]
+        language: system
+  - repo: https://github.com/johann-petrak/licenseheaders.git
+    rev: 'v0.8.8'
+    hooks:
+      - id: licenseheaders
+        args: ["-t", ".github/templates/apache-2.tmpl", "-y2014-2023",
+        "-o", "Key4hep-Project",
+        "-n", "Key4hep",
+        "-u", "https://key4hep.github.io/key4hep-doc/",
+        "-x", ".github/*", ".pre-commit-config.yaml", "README.md",
+              "doc/ReleaseNotes.md",
+        "-f"]