fix some bugs in new workflow (#2094)

Author: rachmari

.github/workflows/triage-unallowed-contributions.yml

@@ -2,6 +2,8 @@ name: Check unallowed file changes
 
 on:
   push:
+  pull_request:
+    types: [opened, reopened]
 
 jobs:
   triage:
@@ -20,8 +22,17 @@ jobs:
               ...context.repo,
               commit_sha: context.sha
             })
+            const pullNumber = pulls.data
+              .map(pull => pull.number)
+              .shift()
 
-            return pulls.data.map(pull => pull.number).shift()
+            if (pullNumber) {
+              console.log(`Pull request number: ${pullNumber}`)
+              return pullNumber
+            } else {
+              console.log(`When this workflow ran, the associated pull request was not yet created. Pushing a new commit after you've created a pull request will automatically re-run this workflow, or you can manually re-run the workflow.`)
+              process.exit(1)
+            }
       - name: Check for existing requested changes
         id: requested-change
         uses: actions/github-script@626af12fe9a53dc2972b48385e7fe7dec79145c9
@@ -34,10 +45,16 @@ jobs:
               pull_number: ${{steps.pull-number.outputs.result}}
             })
 
-            return pullReviews.data
+            const botReviews = pullReviews.data
               .filter(review => review.user.login === 'github-actions[bot]')
               .sort((a, b) => new Date(b.submitted_at) - new Date(a.submitted_at))
               .shift()
+
+            if (botReviews) {
+              console.log(`Pull request reviews authored by the github-action bot: ${botReviews}`)
+            }
+            return botReviews
+
       - name: Get files changed
         uses: dorny/paths-filter@eb75a1edc117d3756a18ef89958ee59f9500ba58
         id: filter
@@ -104,7 +121,9 @@ jobs:
       # When the most recent review was CHANGES_REQUESTED and the existing
       # PR no longer contains unallowed changes, dismiss the previous review
       - name: Dismiss pull request review
-        if: ${{ steps.filter.outputs.notAllowed == 'false' && fromJson(steps.requested-change.outputs.result).state == 'CHANGES_REQUESTED' }}
+        # Check that unallowed files aren't modified and that a
+        # CHANGES_REQUESTED review already exists
+        if: ${{ steps.filter.outputs.notAllowed == 'false' && steps.requested-change.outputs.result && fromJson(steps.requested-change.outputs.result).state == 'CHANGES_REQUESTED' }}
         uses: actions/github-script@626af12fe9a53dc2972b48385e7fe7dec79145c9
         with:
           github-token: ${{secrets.GITHUB_TOKEN}}