From cb4037acc6f184045e9c258e194a16782ad4f4a3 Mon Sep 17 00:00:00 2001
From: Edoardo Zoni <ezoni@lbl.gov>
Date: Mon, 18 Nov 2024 13:38:52 -0800
Subject: [PATCH] Add workflow to check files changed

---
 .github/workflows/check_diff.yml | 49 ++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 .github/workflows/check_diff.yml

diff --git a/.github/workflows/check_diff.yml b/.github/workflows/check_diff.yml
new file mode 100644
index 00000000000..c4ef1c08fe8
--- /dev/null
+++ b/.github/workflows/check_diff.yml
@@ -0,0 +1,49 @@
+name: PR analysis
+
+on:
+  pull_request:
+
+concurrency:
+  group: ${{ github.ref }}-${{ github.head_ref }}-checkdiff
+  cancel-in-progress: true
+
+jobs:
+  check_diff:
+    name: Check files changed
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Define base and head refs
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.ref }}
+          HEAD_REF: ${{ github.event.pull_request.head.ref }}
+        run: |
+          echo "Base ref: ${BASE_REF}"
+          echo "Head ref: ${HEAD_REF}"
+      - name: Add forked repository as remote
+        run: |
+          git remote add fork ${{ github.event.pull_request.head.repo.clone_url }}
+      - name: Fetch base branch from main repository
+        run: |
+          git fetch origin ${BASE_REF}
+      - name: Fetch head branch from forked repository
+        run: |
+          git fetch fork ${HEAD_REF}
+      - name: Get files changed
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.ref }}
+          HEAD_REF: ${{ github.event.pull_request.head.ref }}
+        run: |
+          git diff --name-only --diff-filter=ACMRTUXB origin/${BASE_REF}..fork/${HEAD_REF} > check_diff.txt
+      - name: Check files changed
+        run: |
+          if grep -v -E "^(docs|\.github)/|\.azure-pipelines\.yml$" check_diff.txt; then
+            echo "skip=false" >> ${GITHUB_OUTPUT}
+          else
+            echo "skip=true" >> ${GITHUB_OUTPUT}
+          fi
+    outputs:
+      skip: ${{ steps.check.outputs.skip }}