plugin: add CI with lint

Author: LeoKle

.github/actions/plugin/lint/action.yml

@@ -0,0 +1,22 @@
+name: clang-format check
+description: Checks formatting using clang-format
+
+inputs:
+  source-dir:
+    description: 'Root directory of the cpp project'
+    required: false
+    default: '.'
+
+runs:
+  using: composite
+  steps:
+    - name: Install clang-format
+      shell: bash
+      run: sudo apt-get install -y clang-format
+
+    - name: Run clang-format
+      shell: bash
+      run: |
+        find ${{ inputs.source-dir }}/src ${{ inputs.source-dir }}/tests \
+          -name '*.cpp' -o -name '*.h' | \
+        xargs clang-format --dry-run --Werror

.github/workflows/plugin-ci.yml

@@ -0,0 +1,24 @@
+name: Plugin CI
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'plugin/**'
+      - '.github/**'
+  pull_request:
+    paths:
+      - 'plugin/**'
+      - '.github/**'
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Check formatting
+        uses: ./.github/actions/plugin/lint
+        with:
+          source-dir: plugin

plugin/.clang-format

@@ -1,3 +1,4 @@
 BasedOnStyle: Google
 IndentWidth: 4
-ColumnLimit: 120
+ColumnLimit: 120
+Standard: c++20