add reviewers as assignees on PRs

Signed-off-by: Siddhartha Ganguly <gangulysiddhartha22@gmail.com>

Author: gangulysiddhartha22-cmyk

.github/scripts/bot-pr-add-reviewers-as-assignees.js

@@ -0,0 +1,165 @@
+// =============================================================================
+// Add Reviewers as Assignees Bot
+// =============================================================================
+//
+// This script automatically adds requested reviewers (individuals + expanded 
+// team members) as assignees on a PR. Makes it easier for reviewers to find
+// their PRs via the "Assigned to me" filter.
+//
+// Triggered by:
+//   - pull_request review_requested event
+//   - workflow_dispatch (for manual testing)
+//
+// Key behavior:
+//   - Only adds users who aren't already assignees
+//   - Expands teams with graceful fallback on permission/visibility issues
+//   - Supports dry-run mode
+//   - Batches assignee updates (GitHub limit = 10 per call)
+//   - Comprehensive logging for debugging
+//
+// Called by: .github/workflows/bot-pr-add-reviewers-as-assignees.yml
+
+/**
+ * Checks if the script is running in dry-run mode.
+ *
+ * Returns true if DRY_RUN env var is set to "true" (case-insensitive).
+ */
+function isDryRun() {
+  return /^true$/i.test(process.env.DRY_RUN || '');
+}
+
+/**
+ * Main handler that adds requested reviewers (individuals + expanded team members)
+ * as assignees on a Pull Request.
+ *
+ * @param {Object} params
+ * @param {Object} params.github - GitHub Octokit client from actions/github-script
+ * @param {Object} params.context - GitHub Actions context
+ * @returns {Promise<void>}
+ */
+module.exports = async ({ github, context }) => {
+  const dryRun = isDryRun();
+  if (dryRun) {
+    console.log('[reviewers-assignee] Running in DRY-RUN mode - no changes will be made');
+  }
+
+  try {
+    let prNumber = context.payload.pull_request?.number;
+    let owner = context.repo.owner;
+    let repo = context.repo.repo;
+
+    // Support workflow_dispatch with manual PR number
+    if (context.eventName === 'workflow_dispatch' && context.payload.inputs?.pr_number !== undefined) {
+      const manualPrNumber = Number(context.payload.inputs.pr_number);
+      if (!Number.isInteger(manualPrNumber) || manualPrNumber <= 0) {
+        console.log('[reviewers-assignee] Invalid PR number supplied. Skipping.');
+        return;
+      }
+      prNumber = manualPrNumber;
+    }
+    if (!Number.isInteger(prNumber) || prNumber <= 0) {
+      console.log('[reviewers-assignee] No PR number found. Skipping.');
+      return;
+    }
+
+    console.log(`[reviewers-assignee] Processing PR #${prNumber} in ${owner}/${repo}`);
+
+    // Fetch fresh PR data
+    const { data: pr } = await github.rest.pulls.get({
+      owner,
+      repo,
+      pull_number: prNumber
+    });
+
+    const requestedReviewers = pr.requested_reviewers || [];
+    const requestedTeams = pr.requested_teams || [];
+    const currentAssignees = new Set(pr.assignees?.map(a => a.login) || []);
+
+    console.log(`[reviewers-assignee] Requested reviewers: ${requestedReviewers.length}, teams: ${requestedTeams.length}`);
+
+    const usersToAssign = new Set();
+
+    // Add individual reviewers
+    for (const reviewer of requestedReviewers) {
+      if (reviewer?.login && !currentAssignees.has(reviewer.login)) {
+        usersToAssign.add(reviewer.login);
+      }
+    }
+
+    // Expand teams with pagination
+    for (const team of requestedTeams) {
+      if (!team?.slug) continue;
+      try {
+        const members = await github.paginate(github.rest.teams.listMembersInOrg, {
+          org: owner,
+          team_slug: team.slug,
+          per_page: 100
+        });
+
+        for (const member of members) {
+          if (member?.login && !currentAssignees.has(member.login)) {
+            usersToAssign.add(member.login);
+          }
+        }
+        console.log(`[reviewers-assignee] Expanded team ${team.slug} → ${members.length} members`);
+      } catch (error) {
+        if (error?.status === 403 || error?.status === 404) {
+          console.log(`[reviewers-assignee] Could not expand team ${team.slug} due to permissions/visibility: ${error.message}`);
+          continue;
+        }
+        console.error(`[reviewers-assignee] Failed to expand team ${team.slug}: ${error.message}`);
+        throw error;
+      }
+    }
+
+    if (usersToAssign.size === 0) {
+      console.log('[reviewers-assignee] No new users to assign. Done.');
+      return;
+    }
+
+    const assigneesList = Array.from(usersToAssign);
+    console.log(`[reviewers-assignee] Will assign: ${assigneesList.join(', ')}`);
+
+    if (dryRun) {
+      console.log('[reviewers-assignee] DRY-RUN: Would have added the above users as assignees');
+      return;
+    }
+
+    // Add up to 10 assignees at a time
+    const ASSIGNEE_BATCH_SIZE = 10;
+    let addedCount = 0;
+    let permissionDenied = false;
+    for (let i = 0; i < assigneesList.length; i += ASSIGNEE_BATCH_SIZE) {
+      const batch = assigneesList.slice(i, i + ASSIGNEE_BATCH_SIZE);
+      try {
+        await github.rest.issues.addAssignees({
+          owner,
+          repo,
+          issue_number: prNumber,
+          assignees: batch
+        });
+        addedCount += batch.length;
+        console.log(`[reviewers-assignee] Added batch of ${batch.length} assignees`);
+      } catch (error) {
+        if (error?.status === 403) {
+          permissionDenied = true;
+          console.log('[reviewers-assignee] Skipping remaining assignment due to insufficient permissions');
+          break;
+        }
+        console.error(`[reviewers-assignee] Failed to add assignees batch: ${error.message}`);
+        throw error;   // Re-throw other errors
+      }
+    }
+
+    console.log(
+      permissionDenied
+        ? `[reviewers-assignee] Added ${addedCount} reviewer(s) before permissions blocked further assignment on PR #${prNumber}`
+        : `[reviewers-assignee] Successfully added ${addedCount} reviewer(s) as assignee(s) on PR #${prNumber}`
+    );
+
+  } catch (error) {
+    console.error('[reviewers-assignee] Error:', error.message);
+    if (error.status) console.error('Status:', error.status);
+    throw error;
+  }
+};