#!/usr/bin/env node

/* eslint-disable no-console */

'use strict';

/*

* This script generates the template a changelog by comparing a current version

* with main. Run this, copy what's logged into the `CHANGELOG.md` and update

* the top section based on the changes listed in "Community Contributions"

*

* Usage:

*

* bin/changelog.js

*/

const { Octokit } = require('@octokit/rest');

const execSync = require('child_process').execSync;

const octokit = new Octokit({

auth: process.env.GITHUB_TOKEN,

});

const DEBUG = process.env.DEBUG === 'true';

const debug = (...args) => DEBUG && console.error('[DEBUG]', ...args);

const currentVersion = process.env.PRIOR_VERSION;

const head = (process.env.HEAD || execSync('git rev-parse HEAD', { encoding: 'UTF-8' })).trim();

debug('Current version:', currentVersion);

debug('Head:', head);

generateChangelog()

.then(console.log)

.catch((err) => console.error(err));

async function fetchAllChanges() {

debug('Fetching comparison:', `${currentVersion}...${head}`);

const comparison = await octokit.repos.compareCommitsWithBasehead({

owner: 'emberjs',

repo: 'ember.js',

basehead: `${currentVersion}...${head}`,

per_page: 100,

});

let commits = comparison.data.commits;

const totalCommits = comparison.data.total_commits;

debug('Total commits:', totalCommits, 'Fetched:', commits.length);

// If there are more commits than returned, fetch them page by page

if (totalCommits > commits.length) {

let page = 2;

while (commits.length < totalCommits) {

debug('Fetching page:', page);

const nextPage = await octokit.repos.compareCommitsWithBasehead({

owner: 'emberjs',

repo: 'ember.js',

basehead: `${currentVersion}...${head}`,

per_page: 100,

page: page,

});

commits = commits.concat(nextPage.data.commits);

debug('Now have', commits.length, 'commits');

page++;

// Safety check to prevent infinite loops

if (nextPage.data.commits.length === 0) break;

}

}

return commits;

}

async function generateChangelog() {

let commits = await fetchAllChanges();

debug('Processing', commits.length, 'commits');

let contributions = commits.filter(excludeDependabot).filter(isMergeOrCherryPick);

debug('Found', contributions.length, 'contributions after filtering');

let changes = await Promise.all(

contributions.map(async function (commitInfo) {

let message = await getCommitMessage(commitInfo);

let mergeFromBranchRegex = /#(\d+) from (.+)\//;

let mergePullRequestRegex = /Merge pull request #(\d+)/;

let mergeWithPrReferenceRegex = /\(#(\d+)\)$/m;

let result = {

sha: commitInfo.sha,

};

if (mergeFromBranchRegex.test(message)) {

let match = message.match(mergeFromBranchRegex);

result.number = match[1];

result.title = message.split('\n\n')[1];

} else if (mergePullRequestRegex.test(message)) {

let match = message.match(mergePullRequestRegex);

result.number = match[1];

result.title = message.split('\n\n')[1];

} else if (mergeWithPrReferenceRegex.test(message)) {

let match = message.match(mergeWithPrReferenceRegex);

result.number = match[1];

result.title = message.split('\n')[0];

} else {

result.title = message.split('\n\n')[0];

}

debug('Processed commit:', result.number || result.sha.slice(0, 8), '-', result.title);

return result;

})

);

debug('Sorting and deduplicating changes');

return changes

.sort(comparePrNumber)

.filter(uniqueByPrNumber)

.map((pr) => {

let title = pr.title;

let link;

if (pr.number) {

link =

'[#' + pr.number + ']' + '(https://github.com/emberjs/ember.js/pull/' + pr.number + ')';

} else {

link =

'[' + pr.sha.slice(0, 8) + '](https://github.com/emberjs/ember.js/commit/' + pr.sha + ')';

}

return '- ' + link + ' ' + title;

})

.join('\n');

}

async function getCommitMessage(commitInfo) {

let message = commitInfo.commit.message;

let matches;

if (message.indexOf('cherry picked from commit') > -1) {

debug('Processing cherry-pick commit:', commitInfo.sha.slice(0, 8));

let cherryPickRegex = /cherry picked from commit ([a-z0-9]+)/;

let originalCommit = cherryPickRegex.exec(message)[1];

try {

// command from http://stackoverflow.com/questions/8475448/find-merge-commit-which-include-a-specific-commit

message = execSync(

'commit=$((git rev-list ' +

originalCommit +

'..origin/main --ancestry-path | cat -n; git rev-list ' +

originalCommit +

'..origin/main --first-parent | cat -n) | sort -k2 | uniq -f1 -d | sort -n | tail -1 | cut -f2) && git show --format="%s\n\n%b" $commit',

{ encoding: 'utf8' }

);

debug('Found original merge commit for cherry-pick');

} catch {

debug('Could not find original merge commit for cherry-pick');

// ignored

}

}

if ((matches = message.match(/^Merge pull request #(\d+)/))) {

// if the commit was a merge from a PR and there's no additional content in

// the commit message (which is normally the title of the merged PR) then

// hit the Github API for the PR to get the title.

let prNumber = matches[1];

let lines = message.split(/\n\n/);

if (!lines[1]) {

debug('Fetching PR title for #' + prNumber);

let { data: pullRequest } = await octokit.pulls.get({

owner: 'emberjs',

repo: 'ember.js',

pull_number: prNumber,

});

return `Merge pull request #${prNumber}\n\n${pullRequest.title}`;

}

}

return message;

}

function excludeDependabot(commitInfo) {

let author = commitInfo.author && commitInfo.author.login;

return author !== 'dependabot-preview[bot]' && author !== 'dependabot[bot]';

}

function isMergeOrCherryPick(commitInfo) {

if (commitInfo.parents.length == 2) return true;

let message = commitInfo.commit.message;

return message.indexOf('Merge pull request #') > -1 || message.indexOf('cherry picked from') > -1;

}

function comparePrNumber(a, b) {

if (a.number && !b.number) return -1;

if (!a.number && b.number) return 1;

if (!a.number && !b.number) {

if (a.sha < b.sha) return -1;

if (a.sha > b.sha) return 1;

return 0;

}

if (a.number < b.number) return -1;

if (a.number > b.number) return 1;

return 0;

}

function uniqueByPrNumber(commitInfo, index, commits) {

const foundIndex = commits.findIndex(({ number }) => number === commitInfo.number);

// keep this item if it has a `number` that isn't elsewhere in the array, or doesn't have `number`

return foundIndex === index || foundIndex === -1;

}