Use --diff in CI, resolve #2816

fourjr · fourjr · commit 8efb4ba95015 · 2020-10-28T16:09:12.000+08:00
diff --git a/.github/workflows/lints.yml b/.github/workflows/lints.yml
@@ -31,4 +31,4 @@ jobs:
       continue-on-error: true
     - name: Black and flake8
       run: |
-        black . --check
+        black . --diff
