ci: remove ref option from prettier workflow checkout

.github/workflows/prettify_code.yml

@@ -1,5 +1,4 @@
 name: Prettify Code
-# This action works with pull requests and pushes
 on:
   pull_request:
   push:
@@ -9,19 +8,42 @@ on:
 jobs:
   prettier:
     runs-on: ubuntu-latest
-
     steps:
       - name: Checkout
         uses: actions/checkout@v4
         with:
-          ref: ${{ github.head_ref }}
           fetch-depth: 0
 
-      - name: Prettify code
+      - name: Fetch base branch
+        if: github.event_name == 'pull_request'
+        run: git fetch origin ${{ github.event.pull_request.base.ref }}
+
+      - name: Get changed files
+        id: changed-files
+        run: |
+          if [ "${{ github.event_name }}" == "pull_request" ]; then
+            BASE_SHA="origin/${{ github.event.pull_request.base.ref }}"
+          else
+            BASE_SHA="${{ github.event.before }}"
+          fi
+
+          # Get files and store as space-separated string
+          CHANGED_FILES=$(git diff --name-only --diff-filter=ACMR -z $BASE_SHA HEAD | \
+            grep -zE '\.(js|md)$' | \
+            xargs -0 -r)
+
+          if [ -n "$CHANGED_FILES" ]; then
+            echo "files=$CHANGED_FILES" >> $GITHUB_OUTPUT
+            echo "has_files=true" >> $GITHUB_OUTPUT
+            echo "Changed files: $CHANGED_FILES"
+          else
+            echo "has_files=false" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Check code formatting
+        if: steps.changed-files.outputs.has_files == 'true'
         uses: creyD/[email protected]
         with:
-          # This part is also where you can pass other options, for example:
           prettier_version: 2.8.8
-          prettier_options: --write **/*.{js,md}
-          same_commit: true
-
+          prettier_options: --check ${{ steps.changed-files.outputs.files }}
+          dry: true