Enforce code formatting in PR via git-clang-client (#1383)

In #946 the
codebase was reformatted for consistency, but as this was not enforced
the codebase has drifted since then.

To avoid this happening again, enforce this at the PR stage.

Testing:
- [example
failure](https://github.com/hazelcast/hazelcast-cpp-client/actions/runs/20455944532/job/58777930370)
- [example success

](https://github.com/hazelcast/hazelcast-cpp-client/actions/runs/20455961135/job/58777982668)

This is alternative implementation addressing feedback from
#1342 (comment)

Closes #1342

---------

Co-authored-by: ihsan demir <[email protected]>

Author: JackPGreen

.github/workflows/build-pr.yml

@@ -73,6 +73,7 @@ jobs:
     outputs:
       ref: ${{ steps.get-refs.outputs.ref }}
       merged-ref: ${{ steps.get-refs.outputs.merged-ref }}
+      base-sha: ${{ steps.get-refs.outputs.base-sha }}
 
     steps:
       - name: Get Refs
@@ -85,11 +86,15 @@ jobs:
             echo "PR_COMMIT: ${{ inputs.pr_commit }}"
             echo "ref=refs/pull/${{ inputs.pr_number }}/merge" >> $GITHUB_OUTPUT
             echo "merged-ref=${{ inputs.pr_commit }}" >> $GITHUB_OUTPUT
+            echo "base-sha=$(gh api repos/${GITHUB_REPOSITORY}/pulls/${{ inputs.pr_number }} --jq '.base.sha')" >> "$GITHUB_OUTPUT"
           else
             echo "PR_NUMBER: ${{ github.event.pull_request.number }}"
             echo "ref=refs/pull/${{ github.event.pull_request.number }}/merge" >> $GITHUB_OUTPUT
             echo "merged-ref=''" >> $GITHUB_OUTPUT
+            echo "base-sha=${{ github.event.pull_request.base.sha }}" >> "$GITHUB_OUTPUT"
           fi
+        env:
+          GH_TOKEN: ${{ secrets.GH_TOKEN }}
 
   # run for code-coverage and upload the result as an artifact.
   code-coverage:
@@ -231,3 +236,33 @@ jobs:
           AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
           HZ_TEST_AWS_INSTANCE_PRIVATE_IP: ${{ secrets.HZ_TEST_AWS_INSTANCE_PRIVATE_IP }}
+
+  enforce-code-formatting:
+    runs-on: ubuntu-latest
+    needs: get-refs
+    
+    steps:
+      - name: Install Necessary Packages
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang-format
+
+      - uses: actions/checkout@v5
+        with:
+          ref: ${{ needs.get-refs.outputs.ref }}
+          token: ${{ secrets.GH_TOKEN }}
+          fetch-depth: 0          
+
+      - name: Check formatting
+        run: |
+          source /dev/stdin <<< "$(curl --silent https://raw.githubusercontent.com/hazelcast/github-actions-common-scripts/main/logging.functions.sh)"
+
+          git-clang-format \
+            ${{ needs.get-refs.outputs.base-sha }} \
+            -- \
+            hazelcast
+
+          if ! git --no-pager diff; then
+            echoerr "Code not formatted as expected"
+            exit 1
+          fi