feat: add auto-formatting step with rustfmt to CI/CD pipeline

Author: AdamLBS

.github/workflows/rust.yml

@@ -11,9 +11,44 @@ env:
   RUST_BACKTRACE: 1
 
 jobs:
+  format:
+    name: Auto-format Code
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Setup Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt
+
+      - name: Run cargo fmt
+        run: cargo fmt --all
+
+      - name: Check for changes
+        id: git-check
+        run: |
+          git diff --exit-code || echo "has_changes=true" >> $GITHUB_OUTPUT
+
+      - name: Commit and push if changed
+        if: steps.git-check.outputs.has_changes == 'true'
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add -A
+          git commit -m "style: auto-format code with rustfmt [skip ci]"
+          git push
+
   test:
     name: Test
     runs-on: ubuntu-latest
+    needs: format
+    if: always()
 
     services:
       postgres:
@@ -68,9 +103,6 @@ jobs:
         run: |
           psql -h localhost -U postgres -d e2ee -f sql_models/seed.sql
 
-      - name: Check formatting
-        run: cargo fmt --all -- --check
-
       - name: Clippy
         run: cargo clippy --all-targets --all-features -- -D warnings