Scheduled workflows fixes

- Ensure `spdx.yml` has same fixes as `tapioca.yml`.
- Don't `reset --hard` to ensure that `brew` commands used are those in
  the same branch rather than always from `origin/master`
- Don't check for an existing branch but instead force-push to it if
  there's any updates.
- Provide sample `brew typecheck` command that can be used.

.github/workflows/spdx.yml

@@ -25,16 +25,14 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          cd "$GITHUB_WORKSPACE/Library/Homebrew"
+          git fetch origin master
+          git reset origin/master
+          git checkout -B spdx-update
 
           if brew update-license-data --fail-if-not-changed; then
-            if ! git ls-remote --exit-code --heads origin spdx-update; then
-              git checkout -B spdx-update
-              git reset origin/master
-              git add data/spdx
-              git commit -m "spdx: update license data." -m "Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/spdx.yml)."
-              echo "::set-output name=committed::true"
-            fi
+            git add "$GITHUB_WORKSPACE/Library/Homebrew/data/spdx"
+            git commit -m "spdx: update license data." -m "Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/spdx.yml)."
+            echo "::set-output name=committed::true"
           fi
 
       - name: Push commits
@@ -43,11 +41,10 @@ jobs:
         with:
           token: ${{ secrets.HOMEBREW_GITHUB_API_TOKEN }}
           branch: spdx-update
+          force: true
 
       - name: Open a pull request
         if: steps.update.outputs.committed == 'true'
-        run: |
-          cd "$GITHUB_WORKSPACE/Library/Homebrew"
-          hub pull-request --no-edit
+        run: hub pull-request --no-edit
         env:
           GITHUB_TOKEN: ${{ secrets.HOMEBREW_GITHUB_API_TOKEN }}

.github/workflows/tapioca.yml

@@ -33,22 +33,20 @@ jobs:
       - name: Update Tapioca definitions
         id: update
         run: |
-          cd "$GITHUB_WORKSPACE/Library/Homebrew"
-
           git fetch origin master
-          git reset --hard origin/master
+          git reset origin/master
           git checkout -B tapioca-update
 
           # TODO: replace with `brew typecheck`
+          cd "$GITHUB_WORKSPACE/Library/Homebrew"
           bundle exec tapioca sync --exclude json
           bundle exec srb rbi hidden-definitions
-
           if ! git diff --no-patch --exit-code -- sorbet; then
-            if ! git ls-remote --exit-code --heads origin tapioca-update >/dev/null; then
-              git add sorbet
-              git commit -m "sorbet: update RBI files using Tapioca." -m "Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/tapioca.yml)."
-              echo "::set-output name=committed::true"
-            fi
+
+          # if brew typecheck --update --fail-if-not-changed; then
+            git add "$GITHUB_WORKSPACE/Library/Homebrew/sorbet"
+            git commit -m "sorbet: update RBI files using Tapioca." -m "Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/tapioca.yml)."
+            echo "::set-output name=committed::true"
           fi
 
       - name: Push commits
@@ -57,6 +55,7 @@ jobs:
         with:
           token: ${{ secrets.HOMEBREW_GITHUB_API_TOKEN }}
           branch: tapioca-update
+          force: true
 
       - name: Open a pull request
         if: steps.update.outputs.committed == 'true'