auto-merge-api-doc-updates.yaml

name: Auto-merge API doc updates

on:
  pull_request_target:
    types: [opened, synchronize, reopened]
  # Trigger when the main testing workflow completes
  workflow_run:
    workflows: ["Get PR URL, start dependent jobs"]
    types: [completed]

permissions:
  contents: write
  pull-requests: write

jobs:
  auto-merge:
    runs-on: ubuntu-latest
    steps:
      - name: Get PR details
        id: pr
        uses: actions/github-script@v7
        with:
          script: |
            let prNumber;

            // Determine PR number based on trigger type
            if (context.eventName === 'pull_request_target') {
              prNumber = context.payload.pull_request.number;
              console.log(`trigger type is pull_request_target and PR number is ${prNumber}`)
            } else if (context.eventName === 'workflow_run') {
              console.log('trigger type is workflow_run')
              const headBranch = context.payload.workflow_run.head_branch;
              console.log(`workflow run head branch: ${headBranch}`)

              // Check if workflow_run has pull_requests array
              if (context.payload.workflow_run.pull_requests && context.payload.workflow_run.pull_requests.length > 0) {
                console.log(`found ${context.payload.workflow_run.pull_requests.length} PR(s) in workflow_run payload`)

                // Match PR by head branch to ensure we get the correct one
                const matchingPr = context.payload.workflow_run.pull_requests.find(pr =>
                  pr.head.ref === headBranch
                );

                if (matchingPr) {
                  prNumber = matchingPr.number;
                  console.log(`matched PR #${prNumber} by head branch: ${headBranch}`)
                } else {
                  // Fallback to first PR if no branch match (shouldn't happen)
                  // @todo - after testing let's remove this.
                  prNumber = context.payload.workflow_run.pull_requests[0].number;
                  console.log(`No branch match found, using first PR #${prNumber}`)
                }
              } else {
                console.log('No pull_requests in workflow_run payload, attempting commit lookup')
                // Fallback: Get PR associated with the workflow run's head SHA
                const headSha = context.payload.workflow_run.head_sha;
                console.log(`Head SHA: ${headSha}`)

                const { data: prs } = await github.rest.repos.listPullRequestsAssociatedWithCommit({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  commit_sha: headSha
                });

                // Filter to open PRs with matching head branch
                const matchingPrs = prs.filter(pr =>
                  pr.state === 'open' && pr.head.ref === headBranch
                );

                if (matchingPrs.length === 0) {
                  console.log(`No open PR found with branch ${headBranch} for this workflow run`);
                  return null;
                }

                prNumber = matchingPrs[0].number;
                console.log(`Retrieved PR #${prNumber} from commit lookup matching branch ${headBranch}`)
              }
            } else {
              console.log(`Unexpected event type: ${context.eventName}`);
              return null;
            }

            // Get full PR details
            const { data: pr } = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: prNumber
            });

            console.log(`PR #${pr.number} details:`);
            console.log(`- Author: ${pr.user.login}`);
            console.log(`- Branch: ${pr.head.ref}`);
            console.log(`- From fork: ${pr.head.repo.fork}`);
            console.log(`- Head SHA: ${pr.head.sha}`);
            console.log(`- Triggered by: ${context.eventName}`);

            return {
              number: pr.number,
              author: pr.user.login,
              branch: pr.head.ref,
              is_fork: pr.head.repo.fork,
              head_sha: pr.head.sha
            };

      - name: Check all required checks have passed
        id: check_status
        if: steps.pr.outputs.result != 'null'
        uses: actions/github-script@v7
        with:
          script: |
            const prData = JSON.parse('${{ steps.pr.outputs.result }}');
            const headSha = prData.head_sha;

            // Get combined status for the commit
            const { data: status } = await github.rest.repos.getCombinedStatusForRef({
              owner: context.repo.owner,
              repo: context.repo.repo,
              ref: headSha
            });

            // Get check runs for the commit
            const { data: checkRuns } = await github.rest.checks.listForRef({
              owner: context.repo.owner,
              repo: context.repo.repo,
              ref: headSha
            });

            console.log(`Combined status state: ${status.state}`);
            console.log(`Total statuses: ${status.statuses.length}`);
            console.log(`Total check runs: ${checkRuns.total_count}`);

            // Check if all commit statuses are success
            const allStatusesSuccess = status.statuses.every(s => s.state === 'success');

            // Check if all check runs are success (filtering out skipped and this workflow)
            const relevantCheckRuns = checkRuns.check_runs.filter(run =>
              run.name !== 'auto-merge' &&
              run.conclusion !== 'skipped' &&
              run.conclusion !== null
            );

            const allCheckRunsSuccess = relevantCheckRuns.every(run =>
              run.conclusion === 'success' || run.conclusion === 'neutral'
            );

            console.log('Status check details:');
            status.statuses.forEach(s => {
              console.log(`  - ${s.context}: ${s.state}`);
            });

            console.log('Check run details:');
            relevantCheckRuns.forEach(run => {
              console.log(`  - ${run.name}: ${run.conclusion}`);
            });

            const allChecksPassed = allStatusesSuccess && allCheckRunsSuccess && status.state === 'success';
            console.log(`All checks passed: ${allChecksPassed}`);

            return allChecksPassed;

      - name: Check PR conditions and merge if all conditions are met and tests have passed
        id: check_pr_conditions
        if: steps.check_status.outputs.result == 'true'
        uses: actions/github-script@v7
        with:
          script: |
            let prCanBeMerged = false
            const prData = JSON.parse('${{ steps.pr.outputs.result }}');

            console.log(`Evaluating merge conditions for PR #${prData.number}:`);
            console.log(`- Author: ${prData.author} (expected: platformsh-devrel)`);
            console.log(`- Branch: ${prData.branch} (expected: update-api-doc)`);
            console.log(`- From fork: ${prData.is_fork} (expected: false)`);

            // Check if PR meets all conditions for auto-merge
            if (
              prData.author === 'platformsh-devrel' &&
              prData.branch === 'update-api-doc' &&
              !prData.is_fork
            ) {
              try {
                await github.rest.pulls.merge({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  pull_number: prData.number,
                  merge_method: 'merge',
                  commit_title: `Merge PR #${prData.number}: Update API documentation`,
                  commit_message: `Auto-merged after all checks passed.\n\nBranch: ${prData.branch}\nAuthor: ${prData.author}`
                });

                console.log('PR merged successfully');
                prCanBeMerged = true
              } catch (error) {
                console.error('Failed to auto merge PR:', error.message);
                core.setFailed(error.message);
              }
            } else {
              console.log('Skipping as PR does not meet auto-merge criteria:');
              if (prData.author !== 'platformsh-devrel') {
                console.log(`  - Author mismatch: ${prData.author}`);
              }
              if (prData.branch !== 'update-api-doc') {
                console.log(`  - Branch mismatch: ${prData.branch}`);
              }
              if (prData.is_fork) {
                console.log(`  - PR is from a fork`);
              }
            }

            return prCanBeMerged

      - name: Checks not passed yet
        if: steps.check_status.outputs.result == 'false'
        run: |
          echo "::notice::Not all required checks have passed yet. Auto-merge will not proceed."
          echo "This is normal for PRs that are still running checks. The workflow will run again when the PR is synchronized."

      - name: Pr conditions not met
        if: steps.check_pr_conditions.outputs.result == 'false'
        run: |
          echo "::notice::Conditions not met for a merge to occur. Skipping."