ci: show diffed size report on push event

.github/workflows/size-data.yml

@@ -35,6 +35,17 @@ jobs:
 
       - run: pnpm run size
 
+      - name: Download Previous Size Data
+        uses: dawidd6/action-download-artifact@v2
+        if: ${{ github.event_name == 'push' }}
+        with:
+          branch: main
+          workflow: size-data.yml
+          event: push
+          name: size-data
+          path: temp/size-prev
+          if_no_artifact_found: warn
+
       - name: Upload Size Data
         uses: actions/upload-artifact@v3
         with:
@@ -42,15 +53,14 @@ jobs:
           path: temp/size
 
       - name: Save PR number
-        if: ${{github.event_name == 'pull_request'}}
+        if: ${{ github.event_name == 'pull_request' }}
         run: echo ${{ github.event.number }} > ./pr.txt
 
       - uses: actions/upload-artifact@v3
-        if: ${{github.event_name == 'pull_request'}}
+        if: ${{ github.event_name == 'pull_request' }}
         with:
           name: pr-number
           path: pr.txt
-
       - name: Size report
-        if: ${{github.event_name == 'push'}}
+        if: ${{ github.event_name == 'push' }}
         run: pnpm tsx scripts/size-report.ts