renovate/lib/workers/pr/automerge.ts

import { getAdminConfig } from '../../config/admin';
import { logger } from '../../logger';
import { Pr, platform } from '../../platform';
import { BranchStatus } from '../../types';
import { isBranchModified } from '../../util/git';
import { BranchConfig } from '../types';

export async function checkAutoMerge(
  pr: Pr,
  config: BranchConfig
): Promise<boolean> {
  logger.trace({ config }, 'checkAutoMerge');
  const {
    branchName,
    automerge,
    automergeType,
    automergeComment,
    requiredStatusChecks,
    rebaseRequested,
  } = config;
  logger.debug(
    { automerge, automergeType, automergeComment },
    `Checking #${pr.number} for automerge`
  );
  if (automerge) {
    logger.debug('PR is configured for automerge');
    // Return if PR not ready for automerge
    if (pr.isConflicted) {
      logger.debug('PR is conflicted');
      logger.debug({ pr });
      return false;
    }
    if (requiredStatusChecks && pr.canMerge !== true) {
      logger.debug(
        { canMergeReason: pr.canMergeReason },
        'PR is not ready for merge'
      );
      return false;
    }
    const branchStatus = await platform.getBranchStatus(
      branchName,
      requiredStatusChecks
    );
    if (branchStatus !== BranchStatus.green) {
      logger.debug(
        `PR is not ready for merge (branch status is ${branchStatus})`
      );
      return false;
    }
    // Check if it's been touched
    if (await isBranchModified(branchName)) {
      logger.debug('PR is ready for automerge but has been modified');
      return false;
    }
    if (automergeType === 'pr-comment') {
      logger.debug(`Applying automerge comment: ${automergeComment}`);
      // istanbul ignore if
      if (getAdminConfig().dryRun) {
        logger.info(
          `DRY-RUN: Would add PR automerge comment to PR #${pr.number}`
        );
        return false;
      }
      if (rebaseRequested) {
        await platform.ensureCommentRemoval({
          number: pr.number,
          content: automergeComment,
        });
      }
      return platform.ensureComment({
        number: pr.number,
        topic: null,
        content: automergeComment,
      });
    }
    // Let's merge this
    logger.debug(`Automerging #${pr.number}`);
    // istanbul ignore if
    if (getAdminConfig().dryRun) {
      logger.info(`DRY-RUN: Would merge PR #${pr.number}`);
      return false;
    }
    const res = await platform.mergePr(pr.number, branchName);
    if (res) {
      logger.info({ pr: pr.number, prTitle: pr.title }, 'PR automerged');
    }
    return res;
  }
  logger.debug('No automerge');
  return false;
}