git.js

/**
 * Copyright 2018 The AMP HTML Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
'use strict';

/**
 * @fileoverview Provides functions for executing various git commands.
 */

const colors = require('ansi-colors');
const {
  isTravisBuild,
  isTravisPullRequestBuild,
  travisPullRequestBranch,
  travisPullRequestSha,
} = require('./travis');
const {getStdout} = require('./exec');

const commitLogMaxCount = 100;

/**
 * Returns the merge base of the current branch off of master, regardless of
 * the running environment.
 * @return {string}
 */
exports.gitMergeBaseMaster = function() {
  if (isTravisBuild()) {
    const traviPrSha = travisPullRequestSha();
    return getStdout(`git merge-base master ${traviPrSha}`).trim();
  }
  return gitMergeBaseLocalMaster();
};

/**
 * Returns the `master` parent of the merge commit (current HEAD) on Travis.
 * @return {string}
 */
exports.gitTravisMasterBaseline = function() {
  return getStdout('git rev-parse origin/master').trim();
};

/**
 * Shortens a commit SHA to 7 characters for human readability.
 * @param {string} sha 40 characters SHA.
 * @return {string} 7 characters SHA.
 */
exports.shortSha = function(sha) {
  return sha.substr(0, 7);
};

/**
 * Returns the list of files changed relative to the branch point off of master,
 * one on each line.
 * @return {!Array<string>}
 */
exports.gitDiffNameOnlyMaster = function() {
  const masterBaseline = gitMasterBaseline();
  return getStdout(`git diff --name-only ${masterBaseline}`).trim().split('\n');
};

/**
 * Returns the list of files changed relative to the branch point off of master,
 * in diffstat format.
 * @return {string}
 */
exports.gitDiffStatMaster = function() {
  const masterBaseline = gitMasterBaseline();
  return getStdout(`git -c color.ui=always diff --stat ${masterBaseline}`);
};

/**
 * Returns a detailed log of commits included in a PR check, starting with (and
 * including) the branch point off of master. Limited to at most 100 commits to
 * keep the output sane.
 *
 * @return {string}
 */
exports.gitDiffCommitLog = function() {
  const branchPoint = exports.gitMergeBaseMaster();
  let commitLog = getStdout(`git -c color.ui=always log --graph \
--pretty=format:"%C(red)%h%C(reset) %C(bold cyan)%an%C(reset) \
-%C(yellow)%d%C(reset) %C(reset)%s%C(reset) %C(green)(%cr)%C(reset)" \
--abbrev-commit ${branchPoint}^...HEAD \
--max-count=${commitLogMaxCount}`).trim();
  if (commitLog.split('\n').length >= commitLogMaxCount) {
    commitLog += `\n${colors.yellow('WARNING:')} Commit log is longer than \
${colors.cyan(commitLogMaxCount)} commits. \
Branch ${colors.cyan(exports.gitBranchName())} may not have been forked from \
${colors.cyan('master')}.`;
    commitLog += `\n${colors.yellow('WARNING:')} See \
${colors.cyan('https://github.com/ampproject/amphtml/blob/master/contributing/getting-started-quick.md')} \
for how to fix this.`;
  }
  return commitLog;
};

/**
 * Returns the list of files added by the local branch relative to the branch
 * point off of master, one on each line.
 * @return {!Array<string>}
 */
exports.gitDiffAddedNameOnlyMaster = function() {
  const branchPoint = gitMergeBaseLocalMaster();
  return getStdout(`git diff --name-only --diff-filter=ARC ${branchPoint}`)
      .trim().split('\n');
};

/**
 * Returns the full color diff of the uncommited changes on the local branch.
 * @return {string}
 */
exports.gitDiffColor = function() {
  return getStdout('git -c color.ui=always diff').trim();
};

/**
 * Returns the name of the branch from which the PR originated.
 * @return {string}
 */
exports.gitBranchName = function() {
  return isTravisPullRequestBuild() ?
    travisPullRequestBranch() :
    getStdout('git rev-parse --abbrev-ref HEAD').trim();
};

/**
 * Returns the commit hash of the latest commit.
 * @return {string}
 */
exports.gitCommitHash = function() {
  if (isTravisPullRequestBuild()) {
    return travisPullRequestSha();
  }
  return getStdout('git rev-parse --verify HEAD').trim();
};

/**
 * Returns the email of the author of the latest commit on the local branch.
 * @return {string}
 */
exports.gitCommitterEmail = function() {
  return getStdout('git log -1 --pretty=format:"%ae"').trim();
};

/**
 * Returns the timestamp of the latest commit on the local branch.
 * @return {number}
 */
exports.gitCommitFormattedTime = function() {
  return getStdout(
      'TZ=UTC git log -1 --pretty="%cd" --date=format-local:%y%m%d%H%M%S')
      .trim();
};

/**
 * Returns machine parsable list of uncommitted changed files, or an empty
 * string if no files were changed.
 * @return {string}
 */
exports.gitStatusPorcelain = function() {
  return getStdout('git status --porcelain').trim();
};

/**
 * Returns the merge base of the current branch off of master when running on
 * a local workspace.
 * @return {string}
 */
function gitMergeBaseLocalMaster() {
  return getStdout('git merge-base master HEAD').trim();
}

/**
 * Returns the master baseline commit, regardless of running environment.
 * @return {string}
 */
function gitMasterBaseline() {
  if (isTravisBuild()) {
    return exports.gitTravisMasterBaseline();
  }
  return gitMergeBaseLocalMaster();
}