CI: add slash dispatch workflow to trigger pre-commit checks with comment (#38444)

Author: MarcoGorelli

.github/workflows/autoupdate-pre-commit-config.yml

@@ -23,7 +23,7 @@ jobs:
       - name: Update pre-commit config packages
         uses: technote-space/create-pr-action@v2
         with:
-          GITHUB_TOKEN: ${{ secrets.ACTION_TRIGGER_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           EXECUTE_COMMANDS: |
             pip install pre-commit
             pre-commit autoupdate || (exit 0);

.github/workflows/comment_bot.yml

@@ -0,0 +1,40 @@
+name: Comment-bot
+
+on:
+  issue_comment:
+    types:
+      - created
+      - edited
+
+jobs:
+  autotune:
+    name: "Fixup pre-commit formatting"
+    if: startsWith(github.event.comment.body, '@github-actions pre-commit')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: r-lib/actions/pr-fetch@master
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Cache multiple paths
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cache/pre-commit
+            ~/.cache/pip
+          key: pre-commit-dispatched-${{ runner.os }}-build
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Install-pre-commit
+        run: python -m pip install --upgrade pre-commit
+      - name: Run pre-commit
+        run: pre-commit run --all-files || (exit 0)
+      - name: Commit results
+        run: |
+          git config user.name "$(git log -1 --pretty=format:%an)"
+          git config user.email "$(git log -1 --pretty=format:%ae)"
+          git commit -a -m 'Fixes from pre-commit [automated commit]' || echo "No changes to commit"
+      - uses: r-lib/actions/pr-push@master
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}