From 1cdf60c9b0ab1a59c73833c19d462a92b0220d83 Mon Sep 17 00:00:00 2001
From: Samuel Tardieu <sam@rfc1149.net>
Date: Fri, 10 Jan 2025 11:04:08 +0100
Subject: [PATCH] CI: check the presence of the changelog line in each pull
 request

Checking it only in the merge queue leads to deferred failures once the
decision to merge has been taken already.
---
 .github/workflows/clippy_pr.yml | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/.github/workflows/clippy_pr.yml b/.github/workflows/clippy_pr.yml
index 80523d91f4fc..c24de1e57c79 100644
--- a/.github/workflows/clippy_pr.yml
+++ b/.github/workflows/clippy_pr.yml
@@ -17,8 +17,39 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  changelog:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        # Unsetting this would make so that any malicious package could get our Github Token
+        persist-credentials: false
+
+    # Run
+    - name: Check Changelog
+      run: |
+        set -x
+        body=$(curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" -s "https://api.github.com/repos/rust-lang/rust-clippy/pulls/$PR_NUMBER" | \
+          python -c "import sys, json; print(json.load(sys.stdin)['body'])")
+        cl_line=$(grep "^changelog:\s*\S" <<< "$body") || {
+          echo "ERROR: PR body must contain 'changelog: ...'. Please modify the PR " \
+               "message and push (or force-push) the PR commits to trigger a new check."
+          exit 1
+        }
+        output=$(sed "s/^changelog:\s*//" <<< "$cl_line")
+        if [[ "$output" = "none" ]]; then
+          echo "WARNING: changelog is 'none'"
+        else
+          echo "changelog: $output"
+        fi
+      env:
+        PYTHONIOENCODING: 'utf-8'
+        PR_NUMBER: '${{ github.event.number }}'
   base:
     # NOTE: If you modify this job, make sure you copy the changes to clippy_mq.yml
+    needs: changelog
     runs-on: ubuntu-latest
 
     steps: