nlm/lib/git/commits.js

Lifecycle manager for node projects

/*
 * Copyright (c) 2015, Groupon, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * Neither the name of GROUPON nor the names of its contributors may be
 * used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

'use strict';

const commitParser = require('conventional-commits-parser');

const debug = require('debug')('nlm:git:commits');

const run = require('../run');

const SEPARATOR = '---nlm-split---';
const GIT_LOG_FORMAT = `--format=%H %P\n%B${SEPARATOR}`;
const PR_MERGE_PATTERN = /^Merge pull request #(\d+) from ([^\/]+)\/([\S]+)/;

function parseCommit(commit) {
  const metaEndIdx = commit.indexOf('\n');
  const meta = commit.slice(0, metaEndIdx).trim().split(' ');
  const message = commit.slice(metaEndIdx + 1);
  const sha = meta.shift();
  const parentSha = meta.shift() || null;
  const data = commitParser.sync(message, {
    issuePrefixes: ['#', 'https?://[\\w\\.-/]*[-/]+'],
    revertPattern: /^revert:?\s"([\s\S]*)"/i,
    revertCorrespondence: ['message'],
  });
  const prMatch = message.match(PR_MERGE_PATTERN);

  if (data.revert) {
    data.type = 'pr';
    data.subject = data.revert.message;
    data.header = data.header.replace(/^Revert /, 'revert: ');
  }

  if (prMatch) {
    const prId = prMatch[1];
    data.type = 'pr';
    data.pullId = prId;
    const mergeRef = data.references.find(ref => {
      return ref.issue === prId;
    });

    if (!mergeRef) {
      throw new Error(`Couldn't find reference to merge of PR #${prId}`);
    }

    Object.assign(mergeRef, {
      action: 'Merges',
      owner: prMatch[2],
    });

    if (!mergeRef.repository) {
      mergeRef.repository = null;
    }
  }

  return { ...data, sha: sha || data.sha, parentSha };
}

function isNotRandomMerge(commit) {
  // DotCI adds these :(
  return commit.type || `${commit.header}`.indexOf('Merge ') !== 0;
}

function parseLogOutput(stdout) {
  return stdout
    .split(SEPARATOR)
    .map(s => s.trim())
    .filter(s => !!s)
    .map(parseCommit)
    .filter(isNotRandomMerge);
}

const EMPTY_STATE_MESSAGE =
  /bad default revision 'HEAD'|does not have any commits yet/;

function gracefulEmptyState(error) {
  if (EMPTY_STATE_MESSAGE.test(error.message)) {
    debug('Assuming this was executed before the first commit was made');
    return [];
  }

  throw error;
}

function createRange(fromRevision) {
  if (fromRevision && fromRevision !== 'v0.0.0') {
    return `${fromRevision}..HEAD`;
  }

  return [];
}

function getCommits(directory, fromRevision) {
  return run(
    'git',
    ['log', '--reverse', '--topo-order', GIT_LOG_FORMAT].concat(
      createRange(fromRevision)
    ),
    {
      cwd: directory,
    }
  ).then(parseLogOutput, gracefulEmptyState);
}

module.exports = getCommits;