ci: add force merge automation

.github/workflows/force-merge.yml

@@ -0,0 +1,107 @@
+name: "Force merge automation"
+description: Merge a pull request when N committers post a comment with the command /force-merge
+
+on:
+  issue_comment:
+    types: [created, edited]
+
+permissions:
+  contents: write
+  pull-requests: write
+  issues: read
+
+env:
+  quorum: 3
+
+jobs:
+  force_merge:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check pull request
+        id: should-run
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const issue = await github.rest.issues.get({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo
+            })
+
+            const isPR = issue.data.pull_request != null
+            const isClosed = issue.data.closed_at != null
+            const isDraft = issue.data.draft
+
+            return isPR && !isClosed && !isDraft
+
+      - name: Count votes
+        id: count-votes
+        if: ${{ steps.should-run.outputs.result == 'true' }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const comments = await github.rest.issues.listComments({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo
+            })
+
+            const votes = new Map();
+            for(const comment of comments.data) {
+              const hasVotingRights = comment.author_association === 'MEMBER' || comment.author_association === 'OWNER'
+              const hasCastedVote = comment.body === '/force-merge'
+
+              if(hasVotingRights && hasCastedVote) {
+                votes.set(comment.user.login, comment.author_association);
+              }
+            }
+
+            // Display voters and role
+            console.table(votes)
+
+            return votes.size
+
+      - name: Set lables
+        if: ${{ steps.should-run.outputs.result == 'true' }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const labels = await github.rest.issues.listLabelsOnIssue({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo
+            })
+            const labelsToAdd = []
+            for(const label of labels.data) {
+              if(!label.name.startsWith('force-merge-votes-')) {
+                labelsToAdd.push(label.name)
+              }
+            }
+
+            const votes = ${{ steps.count-votes.outputs.result }}
+            if(votes >= 1 && votes < ${{env.quorum}}) {
+                labelsToAdd.push("force-merge-votes-" + votes)
+            }
+
+            console.log(labelsToAdd) // Debug
+            const result = github.rest.issues.setLabels({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              labels: labelsToAdd
+            })
+
+      - name: Perform merge
+        if: ${{ (steps.should-run.outputs.result == 'true') && (steps.count-votes.outputs.result >= env.quorum) }}
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ secrets.KURA_BOT_GITHUB_TOKEN }}
+          script: |
+            await github.rest.pulls.merge({
+              pull_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              merge_method: "squash"
+            });
+