sync-main-to-next.yml

name: Sync Main to Next

on:
  push:
    branches:
      - main
  workflow_dispatch:
    # Manual trigger to run the same sync logic (main -> next)
    {}

permissions:
  contents: write
  issues: write
  pull-requests: write

jobs:
  sync-branches:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          # Fetch all history for all branches
          fetch-depth: 0
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Configure Git
        run: |
          git config --global user.name "github-actions[bot]"
          git config --global user.email "github-actions[bot]@users.noreply.github.com"

      - name: Create sync branch and PR
        id: create-sync-pr
        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        with:
          script: |
            const { owner, repo } = context.repo;
            const syncBranchName = `sync-main-to-next-${Date.now()}`;

            try {
              // Get the latest commit from main branch
              const mainBranch = await github.rest.repos.getBranch({
                owner,
                repo,
                branch: 'main'
              });

              // Get the next branch reference
              const nextBranch = await github.rest.repos.getBranch({
                owner,
                repo,
                branch: 'next'
              });

              console.log(`Main branch SHA: ${mainBranch.data.commit.sha}`);
              console.log(`Next branch SHA: ${nextBranch.data.commit.sha}`);

              // Check if main and next are already in sync
              if (mainBranch.data.commit.sha === nextBranch.data.commit.sha) {
                console.log('✅ Branches are already in sync, no PR needed');
                core.setOutput('sync_needed', 'false');
                return;
              }

              // Create a new branch from next
              await github.rest.git.createRef({
                owner,
                repo,
                ref: `refs/heads/${syncBranchName}`,
                sha: nextBranch.data.commit.sha
              });

              console.log(`✅ Created sync branch: ${syncBranchName}`);

              // Try to merge main into the sync branch using Git API
              try {
                const mergeResult = await github.rest.repos.merge({
                  owner,
                  repo,
                  base: syncBranchName,
                  head: 'main',
                  commit_message: [
                    "Sync main to next branch",
                    "",
                    "Automatically syncing changes from main branch to next branch.",
                    "",
                    `Source commit: ${mainBranch.data.commit.sha}`
                  ].join('\n')
                });

                console.log(`✅ Successfully merged main into ${syncBranchName}`);
                console.log(`Merge commit SHA: ${mergeResult.data.sha}`);

                // Create pull request
                const pr = await github.rest.pulls.create({
                  owner,
                  repo,
                  title: `🔄 Sync main to next branch`,
                  head: syncBranchName,
                  base: 'next',
                  body: [
                    "## Automatic Branch Sync",
                    "",
                    "This PR automatically syncs changes from `main` to `next` branch.",
                    "",
                    "### Details:",
                    `- **Source branch:** main (${mainBranch.data.commit.sha})`,
                    `- **Target branch:** next (${nextBranch.data.commit.sha})`,
                    "- **Trigger:** Push to main branch",
                    `- **Trigger commit:** ${context.sha}`,
                    "",
                    "### Changes:",
                    "This PR includes all commits from main that are not yet in the next branch.",
                    "",
                    "---",
                    "*This PR was automatically created by the [Sync Main to Next](.github/workflows/sync-main-to-next.yml) workflow.*"
                  ].join('\n'),
                  draft: false
                });

                console.log(`✅ Created PR #${pr.data.number}: ${pr.data.html_url}`);

                // Request review from team (tolerate errors)
                try {
                  await github.rest.pulls.requestReviewers({
                    owner,
                    repo,
                    pull_number: pr.data.number,
                    team_reviewers: ["bugsnag-dev"]
                  });
                } catch (e) {
                  console.log('Reviewer request skipped or failed:', e.message);
                }

                // Enable auto-merge (requires GraphQL)
                const enableAutoMergeQuery = `
                  mutation EnableAutoMerge($pullRequestId: ID!) {
                    enablePullRequestAutoMerge(input: {
                      pullRequestId: $pullRequestId,
                      mergeMethod: MERGE
                    }) {
                      pullRequest {
                        autoMergeRequest {
                          enabledAt
                        }
                      }
                    }
                  }
                `;

                try {
                  await github.graphql(enableAutoMergeQuery, {
                    pullRequestId: pr.data.node_id
                  });
                  console.log('✅ Enabled auto-merge for the PR');
                } catch (autoMergeError) {
                  console.log('⚠️ Could not enable auto-merge:', autoMergeError.message);
                  console.log('Auto-merge may need to be enabled manually or repository settings may not allow it');
                }

                core.setOutput('pr_number', pr.data.number);
                core.setOutput('pr_url', pr.data.html_url);
                core.setOutput('sync_needed', 'true');
                core.setOutput('sync_status', 'success');

              } catch (mergeError) {
                console.log('❌ Merge conflict detected!');
                console.log('Error:', mergeError.message);

                // Delete the sync branch since merge failed
                await github.rest.git.deleteRef({
                  owner,
                  repo,
                  ref: `heads/${syncBranchName}`
                });

                core.setOutput('sync_needed', 'true');
                core.setOutput('sync_status', 'conflict');
                throw mergeError;
              }

            } catch (error) {
              console.error('Error in sync process:', error);
              core.setFailed(error.message);
              throw error;
            }

      - name: Create summary
        if: always()
        run: |
          {
            if [ "${{ steps.create-sync-pr.outputs.sync_needed }}" = "false" ]; then
              echo "## Branches Already in Sync ✅"
              echo ""
              echo "No sync needed - \`main\` and \`next\` branches are already in sync."
            elif [ "${{ steps.create-sync-pr.outputs.sync_status }}" = "success" ]; then
              echo "## Sync PR Created ✅"
              echo ""
              echo "Successfully created a pull request to sync changes from \`main\` to \`next\` branch."
              echo ""
              echo "### Details:"
              echo "- **Pull Request:** [#${{ steps.create-sync-pr.outputs.pr_number }}](${{ steps.create-sync-pr.outputs.pr_url }})"
              echo "- **Source branch:** main"
              echo "- **Target branch:** next"
              echo "- **Auto-merge:** Enabled (will merge after review approval)"
              echo "- **Trigger commit:** ${{ github.sha }}"
            elif [ "${{ steps.create-sync-pr.outputs.sync_status }}" = "conflict" ]; then
              echo "## Sync Failed - Conflicts Detected ❌"
              echo ""
              echo "**Merge conflict detected!** Manual intervention required."
              echo ""
              echo "### What happened:"
              echo "- Attempted to merge \`main\` into \`next\` branch"
              echo "- Conflicts were detected that require manual resolution"
              echo "- No PR was created due to conflicts"
              echo ""
              echo "### Next steps:"
              echo "1. Manually create a branch from \`next\`"
              echo "2. Merge \`main\` and resolve conflicts"
              echo "3. Create a PR to merge the resolved changes into \`next\`"
              echo ""
              echo "### Trigger Details:"
              echo "- **Source branch:** main"
              echo "- **Target branch:** next"
              echo "- **Trigger commit:** ${{ github.sha }}"
            else
              echo "## Sync Status Unknown ⚠️"
              echo ""
              echo "The sync process completed with an unknown status."
            fi
          } >> "$GITHUB_STEP_SUMMARY"

      - name: Create Issue on Conflict
        if: failure() && steps.create-sync-pr.outputs.sync_status == 'conflict'
        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        with:
          script: |
            const issue = await github.rest.issues.create({
              owner: context.repo.owner,
              repo: context.repo.repo,
              title: '🚨 Branch Sync Conflict: main → next',
              body: [
                "## Automatic Branch Sync Failed",
                "",
                "A merge conflict was detected when attempting to sync changes from `main` to `next` branch.",
                "",
                `**Trigger Commit:** ${context.sha}`,
                `**Workflow Run:** [${context.runId}](${context.payload.repository.html_url}/actions/runs/${context.runId})`,
                "",
                "### Manual Resolution Required",
                "",
                "Please follow these steps to resolve the conflict:",
                "",
                "1. **Create a new branch from next:**",
                "   ```bash",
                "   git checkout next",
                "   git pull origin next",
                "   git checkout -b sync-main-to-next-manual",
                "   ```",
                "",
                "2. **Merge main and resolve conflicts:**",
                "   ```bash",
                "   git merge main",
                "   # Resolve any conflicts in your editor",
                "   git add .",
                "   git commit",
                "   ```",
                "",
                "3. **Create a Pull Request:**",
                "   ```bash",
                "   git push origin sync-main-to-next-manual",
                "   # Then create a PR from sync-main-to-next-manual to next",
                "   ```",
                "",
                "4. **Close this issue** once the sync PR is merged.",
                "",
                "### Files Likely to Have Conflicts",
                "",
                "Check these common conflict areas:",
                "- `package.json` (version numbers)",
                "- `CHANGELOG.md` (release notes)",
                "- Configuration files",
                "- Documentation updates",
                "",
                "---",
                "*This issue was automatically created by the [Sync Main to Next](.github/workflows/sync-main-to-next.yml) workflow.*"
              ].join('\n'),
              labels: ['bug', 'automation', 'merge-conflict']
            });

            console.log('Created issue:', issue.data.html_url);