From 2cdf09eab897cfaa3c483d3337e5cfdb68bfd858 Mon Sep 17 00:00:00 2001
From: Rod Vagg <rod@vagg.org>
Date: Fri, 3 Dec 2021 17:38:34 +1100
Subject: [PATCH 1/3] feat!: switch to ESM, fix output colourising, dedupe more
 code w/ branch-diff

* upgrade all deps, including ESM-only deps
* --simple is now default output, including colourising, with
  --markdown being an opt-in output format.
* move process + print logic to separate module for exporting
  for simplifying branch-diff
* add --sha and --reverse options from branch-diff to dedupe some
  processing code

Fixes: https://github.com/nodejs/changelog-maker/issues/120
Closes: https://github.com/nodejs/changelog-maker/pull/107
Closes: https://github.com/nodejs/changelog-maker/pull/119
---
 README.md                |   7 +-
 changelog-maker.js       | 169 ++++++++++++---------------------------
 collect-commit-labels.js |  80 +++++++++---------
 commit-to-output.js      |  29 +++----
 format.mjs => format.js  |   4 +-
 group-commits.js         |   8 +-
 groups.js                |  29 ++++---
 package.json             |  28 ++++---
 process-commits.js       |  75 +++++++++++++++++
 reverts.js               |   9 +--
 test.js                  |  31 +++----
 11 files changed, 230 insertions(+), 239 deletions(-)
 rename format.mjs => format.js (85%)
 create mode 100644 process-commits.js

diff --git a/README.md b/README.md
index e004449..a129f36 100644
--- a/README.md
+++ b/README.md
@@ -44,12 +44,15 @@ npm i changelog-maker -g
 
 ## Usage
 
-**`changelog-maker [--simple] [--group] [--commit-url=<url/with/{ref}>] [--start-ref=<ref>] [--end-ref=<ref>] [github-user[, github-project]]`**
+**`changelog-maker [--plaintext|p] [--markdown|md] [--sha] [--group|-g] [--reverse] [--commit-url=<url/with/{ref}>] [--start-ref=<ref>] [--end-ref=<ref>] [github-user[, github-project]]`**
 
 `github-user` and `github-project` should point to the GitHub repository that can be used to find the `PR-URL` data if just an issue number is provided and will also impact how the PR-URL issue numbers are displayed
 
-* `--simple`:          print a simple form, without additional Markdown cruft
+* `--plaintext`:       print a very simple form, without commit details, implies `--group`
+* `--markdown`:        print a Markdown formatted from, with links and proper escaping
+* `--sha`:             print only the list of short-form commit hashes
 * `--group`:           reorder commits so that they are listed in groups where the `xyz:` prefix of the commit message defines the group. Commits are listed in original order _within_ group.
+* `--reverse`:         reverse the order of commits when printed, does not work with `--reverse`
 * `--commit-url`:      pass in a url template which will be used to generate commit URLs for a repository not hosted in Github. `{ref}` is the placeholder that will be replaced with the commit, i.e. `--commit-url=https://gitlab.com/myUser/myRepo/commit/{ref}`
 * `--start-ref=<ref>`: use the given git `<ref>` as a starting point rather than the _last tag_. The `<ref>` can be anything commit-ish including a commit sha, tag, branch name. If you specify a `--start-ref` argument the commit log will not be pruned so that version commits and `working on <version>` commits are left in the list.
 * `--end-ref=<ref>`:   use the given git `<ref>` as a end-point rather than the _now_. The `<ref>` can be anything commit-ish including a commit sha, tag, branch name.
diff --git a/changelog-maker.js b/changelog-maker.js
index af6af73..f5336d6 100755
--- a/changelog-maker.js
+++ b/changelog-maker.js
@@ -1,42 +1,26 @@
 #!/usr/bin/env node
 
-'use strict'
-
-const fs = require('fs')
-const path = require('path')
-const split2 = require('split2')
-const list = require('list-stream')
-const stripAnsi = require('strip-ansi')
-const pkgtoId = require('pkg-to-id')
-const commitStream = require('commit-stream')
-const gitexec = require('gitexec')
-const { commitToOutput, formatType } = require('./commit-to-output')
-const groupCommits = require('./group-commits')
-const collectCommitLabels = require('./collect-commit-labels')
-const { isReleaseCommit, toGroups } = require('./groups')
-const pkg = require('./package.json')
-const debug = require('debug')(pkg.name)
-const argv = require('minimist')(process.argv.slice(2))
-
-// Skip on formatting on Node.js 10.
-const formatMarkdown = process.versions.node.startsWith('10.') ? false : import('./format.mjs')
-
-const quiet = argv.quiet || argv.q
+import { existsSync, readFileSync } from 'fs'
+import { join } from 'path'
+import process from 'process'
+import stream from 'stream'
+import split2 from 'split2'
+import pkgtoId from 'pkg-to-id'
+import commitStream from 'commit-stream'
+import gitexec from 'gitexec'
+import _debug from 'debug'
+import minimist from 'minimist'
+import { processCommits } from './process-commits.js'
+import { isReleaseCommit } from './groups.js'
+
+const { pipeline } = stream.promises
+const debug = _debug('changelog-maker')
+const argv = minimist(process.argv.slice(2))
 const help = argv.h || argv.help
-const commitUrl = argv['commit-url'] || 'https://github.com/{ghUser}/{ghRepo}/commit/{ref}'
-const pkgFile = path.join(process.cwd(), 'package.json')
-const pkgData = fs.existsSync(pkgFile) ? require(pkgFile) : {}
+const pkgFile = join(process.cwd(), 'package.json')
+const pkgData = existsSync(pkgFile) ? JSON.parse(readFileSync(pkgFile)) : {}
 const pkgId = pkgtoId(pkgData)
 
-const getFormat = () => {
-  if (argv.simple || argv.s) {
-    return formatType.SIMPLE
-  } else if (argv.plaintext || argv.p) {
-    return formatType.PLAINTEXT
-  }
-  return formatType.MARKDOWN
-}
-
 const ghId = {
   user: argv._[0] || pkgId.user || 'nodejs',
   repo: argv._[1] || (pkgId.name && stripScope(pkgId.name)) || 'node'
@@ -58,14 +42,11 @@ if (help) {
 }
 
 function showUsage () {
-  let usage = fs.readFileSync(path.join(__dirname, 'README.md'), 'utf8')
+  const usage = readFileSync(new URL('README.md', import.meta.url), 'utf8')
     .replace(/[\s\S]+(## Usage\n[\s\S]*)\n## [\s\S]+/m, '$1')
-  if (process.stdout.isTTY) {
-    usage = usage
-      .replace(/## Usage\n[\s]*/m, '')
-      .replace(/\*\*/g, '')
-      .replace(/`/g, '')
-  }
+    .replace(/## Usage\n[\s]*/m, 'Usage: ')
+    .replace(/\*\*/g, '')
+    .replace(/`/g, '')
 
   process.stdout.write(usage)
 }
@@ -81,6 +62,18 @@ function replace (s, m) {
   return s
 }
 
+const _startrefcmd = replace(refcmd, { ref: argv['start-ref'] || defaultRef })
+const _endrefcmd = argv['end-ref'] && replace(refcmd, { ref: argv['end-ref'] })
+const _sincecmd = replace(commitdatecmd, { refcmd: _startrefcmd })
+const _untilcmd = argv['end-ref'] ? replace(commitdatecmd, { refcmd: _endrefcmd }) : untilcmd
+const _gitcmd = replace(gitcmd, { sincecmd: _sincecmd, untilcmd: _untilcmd })
+
+debug('%s', _startrefcmd)
+debug('%s', _endrefcmd)
+debug('%s', _sincecmd)
+debug('%s', _untilcmd)
+debug('%s', _gitcmd)
+
 function organiseCommits (list) {
   if (argv['start-ref'] || argv.a || argv.all) {
     if (argv['filter-release']) {
@@ -105,86 +98,22 @@ function organiseCommits (list) {
   })
 }
 
-async function printCommits (list) {
-  for await (let commit of list) {
-    if (!process.stdout.isTTY) {
-      commit = stripAnsi(commit)
-    }
-    process.stdout.write(commit)
-  }
-}
-
-function onCommitList (err, list) {
-  if (err) {
-    return fatal(err)
-  }
-
-  list = organiseCommits(list)
-
-  collectCommitLabels(list, (err) => {
-    if (err) {
-      return fatal(err)
-    }
-
-    if (argv.group) {
-      list = groupCommits(list)
-    }
-
-    const format = getFormat()
-    if (format === formatType.PLAINTEXT) {
-      const formatted = []
-
-      let currentGroup
-      for (const commit of list) {
-        const commitGroup = toGroups(commit.summary)
-        if (currentGroup !== commitGroup) {
-          formatted.push(`${commitGroup}:`)
-          currentGroup = commitGroup
-        }
-        formatted.push(commitToOutput(commit, formatType.PLAINTEXT, ghId, commitUrl))
+async function run () {
+  let commitList = []
+  await pipeline(
+    gitexec.exec(process.cwd(), _gitcmd),
+    split2(),
+    commitStream(ghId.user, ghId.repo),
+    async function * (source) {
+      for await (const commit of source) {
+        commitList.push(commit)
       }
-
-      list = formatted.map((line) => `${line}\n`)
-    } else {
-      list = list.map(async (commit) => {
-        let output = commitToOutput(commit, format, ghId, commitUrl)
-        if (format === formatType.MARKDOWN) {
-          if (!process.stdout.isTTY) {
-            output = stripAnsi(output)
-          }
-          if (process.versions.node.startsWith('10.')) {
-            return `${output}\n`
-          }
-          return formatMarkdown.then((module) => module.default(output))
-        }
-        return `${output}\n`
-      })
-    }
-
-    if (!quiet) {
-      printCommits(list)
-    }
-  })
+    })
+  commitList = organiseCommits(commitList)
+  await processCommits(argv, ghId, commitList)
 }
 
-function fatal (err) {
-  console.error(`Fatal error: ${err.message}`)
+run().catch((err) => {
+  console.error(err)
   process.exit(1)
-}
-
-const _startrefcmd = replace(refcmd, { ref: argv['start-ref'] || defaultRef })
-const _endrefcmd = argv['end-ref'] && replace(refcmd, { ref: argv['end-ref'] })
-const _sincecmd = replace(commitdatecmd, { refcmd: _startrefcmd })
-const _untilcmd = argv['end-ref'] ? replace(commitdatecmd, { refcmd: _endrefcmd }) : untilcmd
-const _gitcmd = replace(gitcmd, { sincecmd: _sincecmd, untilcmd: _untilcmd })
-
-debug('%s', _startrefcmd)
-debug('%s', _endrefcmd)
-debug('%s', _sincecmd)
-debug('%s', _untilcmd)
-debug('%s', _gitcmd)
-
-gitexec.exec(process.cwd(), _gitcmd)
-  .pipe(split2())
-  .pipe(commitStream(ghId.user, ghId.repo))
-  .pipe(list.obj(onCommitList))
+})
diff --git a/collect-commit-labels.js b/collect-commit-labels.js
index 17e322a..4c6da41 100644
--- a/collect-commit-labels.js
+++ b/collect-commit-labels.js
@@ -1,8 +1,9 @@
 'use strict'
 
-const ghauth = require('ghauth')
-const ghissues = require('ghissues')
-const async = require('async')
+import { promisify } from 'util'
+import ghauth from 'ghauth'
+import ghissues from 'ghissues'
+import async from 'async'
 
 const authOptions = {
   configName: 'changelog-maker',
@@ -10,58 +11,53 @@ const authOptions = {
   noDeviceFlow: true
 }
 
-function collectCommitLabels (list, callback) {
+export async function collectCommitLabels (list) {
   const sublist = list.filter((commit) => {
     return typeof commit.ghIssue === 'number' && commit.ghUser && commit.ghProject
   })
 
   if (!sublist.length) {
-    return setImmediate(callback)
+    return
   }
 
-  ghauth(authOptions, (err, authData) => {
-    if (err) {
-      return callback(err)
-    }
-
-    const cache = {}
-
-    const q = async.queue((commit, next) => {
-      function onFetch (err, issue) {
-        if (err) {
-          console.error('Error fetching issue #%s: %s', commit.ghIssue, err.message)
-          return next()
-        }
+  const authData = await promisify(ghauth)(authOptions)
 
-        if (issue.labels) {
-          commit.labels = issue.labels.map((label) => label.name)
-        }
+  const cache = {}
 
-        next()
+  const q = async.queue((commit, next) => {
+    function onFetch (err, issue) {
+      if (err) {
+        console.error('Error fetching issue #%s: %s', commit.ghIssue, err.message)
+        return next()
       }
 
-      if (commit.ghUser === 'iojs') {
-        commit.ghUser = 'nodejs' // forcibly rewrite as the GH API doesn't do it for us
+      if (issue.labels) {
+        commit.labels = issue.labels.map((label) => label.name)
       }
 
-      // To prevent multiple simultaneous requests for the same issue
-      // from hitting the network at the same time, immediately assign a Promise
-      // to the cache that all commits with the same ghIssue value will use.
-      const key = `${commit.ghUser}/${commit.ghProject}#${commit.ghIssue}`
-      cache[key] = cache[key] || new Promise((resolve, reject) => {
-        ghissues.get(authData, commit.ghUser, commit.ghProject, commit.ghIssue, (err, issue) => {
-          if (err) {
-            return reject(err)
-          }
+      next()
+    }
 
-          resolve(issue)
-        })
+    if (commit.ghUser === 'iojs') {
+      commit.ghUser = 'nodejs' // forcibly rewrite as the GH API doesn't do it for us
+    }
+
+    // To prevent multiple simultaneous requests for the same issue
+    // from hitting the network at the same time, immediately assign a Promise
+    // to the cache that all commits with the same ghIssue value will use.
+    const key = `${commit.ghUser}/${commit.ghProject}#${commit.ghIssue}`
+    cache[key] = cache[key] || new Promise((resolve, reject) => {
+      ghissues.get(authData, commit.ghUser, commit.ghProject, commit.ghIssue, (err, issue) => {
+        if (err) {
+          return reject(err)
+        }
+
+        resolve(issue)
       })
-      cache[key].then((val) => onFetch(null, val), (err) => onFetch(err))
-    }, 15)
-    q.drain(callback)
-    q.push(sublist)
-  })
-}
+    })
+    cache[key].then((val) => onFetch(null, val), (err) => onFetch(err))
+  }, 15)
 
-module.exports = collectCommitLabels
+  q.push(sublist)
+  await q.drain()
+}
diff --git a/commit-to-output.js b/commit-to-output.js
index 9be9fd3..8acd536 100644
--- a/commit-to-output.js
+++ b/commit-to-output.js
@@ -1,13 +1,12 @@
-'use strict'
-
-const chalk = require('chalk')
-const reverts = require('./reverts')
-const groups = require('./groups')
+import chalk from 'chalk'
+import { isRevert, cleanSummary as cleanRevertSummary } from './reverts.js'
+import { toGroups, cleanSummary as cleanGroupSummary } from './groups.js'
 
 function cleanUnsupportedMarkdown (txt) {
   // escape _~*\[]<>`
   return txt.replace(/([_~*\\[\]<>`])/g, '\\$1')
 }
+
 function cleanMarkdown (txt) {
   // Escape backticks for edge case scenarii (no code span support).
   if (txt.includes('``') || txt.includes('\\`')) {
@@ -30,7 +29,8 @@ function cleanMarkdown (txt) {
   return cleanMdString
 }
 
-const formatType = {
+export const formatType = {
+  SHA: 'sha',
   PLAINTEXT: 'plaintext',
   MARKDOWN: 'markdown',
   SIMPLE: 'simple'
@@ -65,7 +65,7 @@ function toStringSimple (data) {
   s = s.trim()
 
   return (data.semver && data.semver.length)
-    ? chalk.green(chalk.bold(s))
+    ? chalk.green.bold(s)
     : (data.group === 'doc'
         ? chalk.grey(s)
         : s)
@@ -84,13 +84,13 @@ function toStringMarkdown (data) {
   s = s.trim()
 
   return (data.semver && data.semver.length)
-    ? chalk.green(chalk.bold(s))
+    ? chalk.green.bold(s)
     : (data.group === 'doc'
         ? chalk.grey(s)
         : s)
 }
 
-function commitToOutput (commit, format, ghId, commitUrl) {
+export function commitToOutput (commit, format, ghId, commitUrl) {
   const data = {}
   const prUrlMatch = commit.prUrl && commit.prUrl.match(/^https?:\/\/.+\/([^/]+\/[^/]+)\/\w+\/\d+$/i)
   const urlHash = `#${commit.ghIssue}` || commit.prUrl
@@ -99,9 +99,9 @@ function commitToOutput (commit, format, ghId, commitUrl) {
   data.sha = commit.sha
   data.shaUrl = commitUrl.replace(/\{ghUser\}/g, ghId.user).replace(/\{ghRepo\}/g, ghId.repo).replace(/\{ref\}/g, ref)
   data.semver = commit.labels && commit.labels.filter((l) => l.includes('semver'))
-  data.revert = reverts.isRevert(commit.summary)
-  data.group = groups.toGroups(commit.summary)
-  data.summary = groups.cleanSummary(reverts.cleanSummary(commit.summary))
+  data.revert = isRevert(commit.summary)
+  data.group = toGroups(commit.summary)
+  data.summary = cleanGroupSummary(cleanRevertSummary(commit.summary))
   data.author = (commit.author && commit.author.name) || ''
   data.pr = prUrlMatch && ((prUrlMatch[1] !== `${ghId.user}/${ghId.repo}` ? prUrlMatch[1] : '') + urlHash)
   data.prUrl = prUrlMatch && commit.prUrl
@@ -114,8 +114,3 @@ function commitToOutput (commit, format, ghId, commitUrl) {
 
   return toStringMarkdown(data)
 }
-
-module.exports = {
-  commitToOutput,
-  formatType
-}
diff --git a/format.mjs b/format.js
similarity index 85%
rename from format.mjs
rename to format.js
index f9f83a1..056d253 100644
--- a/format.mjs
+++ b/format.js
@@ -8,9 +8,7 @@ const formatter = remark()
   .use(presetLintNode)
   .use(remarkStringify)
 
-const format = async (markdown) => {
+export async function formatMarkdown (markdown) {
   const result = await formatter.process(markdown)
   return result.toString()
 }
-
-export default format
diff --git a/group-commits.js b/group-commits.js
index 6e6f86b..1066654 100644
--- a/group-commits.js
+++ b/group-commits.js
@@ -1,8 +1,6 @@
-'use strict'
+import { toGroups } from './groups.js'
 
-const { toGroups } = require('./groups')
-
-function groupCommits (list) {
+export function groupCommits (list) {
   const groupList = list.reduce((groupList, commit) => {
     const group = toGroups(commit.summary) || '*'
 
@@ -18,5 +16,3 @@ function groupCommits (list) {
     return p.concat(groupList[group])
   }, [])
 }
-
-module.exports = groupCommits
diff --git a/groups.js b/groups.js
index 9797114..794dbde 100644
--- a/groups.js
+++ b/groups.js
@@ -1,45 +1,44 @@
+import { fileURLToPath } from 'url'
+import process from 'process'
+import { readFileSync } from 'fs'
+import { cleanSummary as cleanRevertsSummary } from './reverts.js'
+
 const groupRe = /^((:?\w|-|,|, )+):\s*/i
-const reverts = require('./reverts')
 
-function toGroups (summary) {
-  summary = reverts.cleanSummary(summary)
+export function toGroups (summary) {
+  summary = cleanRevertsSummary(summary)
   const m = summary.match(groupRe)
   return (m && m[1]) || ''
 }
 
-function cleanSummary (summary) {
+export function cleanSummary (summary) {
   return (summary || '').replace(groupRe, '')
 }
 
 /*
-
-to test this, run on the commandline:
+To test this, run on the command line in a nodejs/node clone:
 
 for br in v4.x v5.x v6.x v7.x; do git log $br --format='%s' | grep -E '^\d+.*elease$' >> /tmp/release-commits-all.txt; done
 sort /tmp/release-commits-all.txt | uniq > /tmp/release-commits.txt
 rm /tmp/release-commits-all.txt
 
-then in this directory:
+Then in this directory:
 
 node groups.js /tmp/release-commits.txt
 
-doesn't cover false positives though
+It doesn't cover false positives though.
 */
 
-function isReleaseCommit (summary) {
+export function isReleaseCommit (summary) {
   return /^Working on v?\d{1,2}\.\d{1,3}\.\d{1,3}$/.test(summary) ||
     /^\d{4}-\d{2}-\d{2},? (Node\.js|Version) v?\d{1,2}\.\d{1,3}\.\d{1,3} (["'][A-Za-z ]+["'] )?\((Current|Stable|LTS|Maintenance)\)/.test(summary) ||
     /^\d{4}-\d{2}-\d{2},? io.js v\d{1,2}\.\d{1,3}\.\d{1,3} Release/.test(summary) ||
     /^\d+\.\d+\.\d+$/.test(summary) // `npm version X` style commit
 }
 
-module.exports.toGroups = toGroups
-module.exports.cleanSummary = cleanSummary
-module.exports.isReleaseCommit = isReleaseCommit
-
-if (require.main === module) {
+if (process.argv[1] === fileURLToPath(import.meta.url)) {
   console.log(`Running tests on lines in ${process.argv[2]}...`)
-  const failures = require('fs').readFileSync(process.argv[2], 'utf8').split('\n').filter(Boolean).filter((summary) => {
+  const failures = readFileSync(process.argv[2], 'utf8').split('\n').filter(Boolean).filter((summary) => {
     return !isReleaseCommit(summary)
   })
   if (!failures.length) {
diff --git a/package.json b/package.json
index 27c1fc4..f7f53b5 100644
--- a/package.json
+++ b/package.json
@@ -3,9 +3,14 @@
   "version": "2.8.0",
   "description": "A git log to CHANGELOG.md tool",
   "main": "changelog-maker.js",
+  "type": "module",
   "bin": {
     "changelog-maker": "./changelog-maker.js"
   },
+  "exports": {
+    "./groups": "./groups.js",
+    "./process-commits": "./process-commits.js"
+  },
   "author": "Rod <rod@vagg.org> (https://r.va.gg/)",
   "license": "MIT",
   "repository": {
@@ -19,26 +24,25 @@
   "keywords": [],
   "preferGlobal": true,
   "dependencies": {
-    "async": "^3.2.0",
-    "chalk": "^4.1.0",
+    "async": "^3.2.2",
+    "chalk": "^5.0.0",
     "commit-stream": "^1.1.0",
-    "debug": "^4.3.1",
+    "debug": "^4.3.3",
     "ghauth": "^5.0.1",
     "ghissues": "^1.1.4",
     "gitexec": "^2.0.1",
-    "list-stream": "^2.0.0",
     "minimist": "^1.2.5",
-    "pkg-to-id": "0.0.3",
-    "remark": "^14.0.1",
-    "remark-parse": "^10.0.0",
-    "remark-preset-lint-node": "^3.2.0",
-    "remark-stringify": "^10.0.0",
-    "split2": "^4.0.0",
-    "strip-ansi": "^6.0.0"
+    "pkg-to-id": "^0.0.3",
+    "remark": "^14.0.2",
+    "remark-parse": "^10.0.1",
+    "remark-preset-lint-node": "^3.3.0",
+    "remark-stringify": "^10.0.2",
+    "split2": "^4.1.0",
+    "strip-ansi": "^7.0.1"
   },
   "devDependencies": {
     "standard": "^16.0.4",
-    "tap": "^15.0.1"
+    "tap": "^15.1.5"
   },
   "scripts": {
     "lint": "standard",
diff --git a/process-commits.js b/process-commits.js
new file mode 100644
index 0000000..0ee0312
--- /dev/null
+++ b/process-commits.js
@@ -0,0 +1,75 @@
+import stripAnsi from 'strip-ansi'
+import { commitToOutput, formatType } from './commit-to-output.js'
+import { groupCommits } from './group-commits.js'
+import { toGroups } from './groups.js'
+import { formatMarkdown } from './format.js'
+import { supportsColor } from 'chalk'
+import { collectCommitLabels } from './collect-commit-labels.js'
+
+function getFormat (argv) {
+  if (argv.sha) {
+    return formatType.SHA
+  } else if (argv.plaintext || argv.p) {
+    return formatType.PLAINTEXT
+  } else if (argv.markdown || argv.md) {
+    return formatType.MARKDOWN
+  }
+  return formatType.SIMPLE
+}
+
+async function printCommits (list) {
+  for (let commit of list) {
+    if (!supportsColor) {
+      commit = stripAnsi(commit)
+    }
+    process.stdout.write(`${commit}\n`)
+  }
+}
+
+export async function processCommits (argv, ghId, list) {
+  const quiet = argv.quiet || argv.q
+  const reverse = argv.reverse
+  const commitUrl = argv['commit-url'] || 'https://github.com/{ghUser}/{ghRepo}/commit/{ref}'
+
+  await collectCommitLabels(list)
+
+  const format = getFormat(argv)
+
+  if (argv.group || argv.g || format === formatType.PLAINTEXT) {
+    list = groupCommits(list)
+  }
+
+  if (format === formatType.SHA) {
+    list = list.map((commit) => `${commit.sha.substr(0, 10)}`)
+  } else if (format === formatType.PLAINTEXT) {
+    const formatted = []
+
+    let currentGroup
+    for (const commit of list) {
+      const commitGroup = toGroups(commit.summary)
+      if (currentGroup !== commitGroup) {
+        formatted.push(`${commitGroup}:`)
+        currentGroup = commitGroup
+      }
+      formatted.push(commitToOutput(commit, formatType.PLAINTEXT, ghId, commitUrl))
+    }
+    list = formatted
+  } else {
+    list = await Promise.all(list.map(async (commit) => {
+      let output = commitToOutput(commit, format, ghId, commitUrl)
+      if (format === formatType.MARKDOWN) {
+        output = stripAnsi(output)
+        return (await formatMarkdown(output)).replace(/\n$/, '')
+      }
+      return output
+    }))
+  }
+
+  if (format !== formatType.PLAINTEXT && reverse) {
+    list = list.reverse()
+  }
+
+  if (!quiet) {
+    printCommits(list)
+  }
+}
diff --git a/reverts.js b/reverts.js
index 6ce99e3..069c987 100644
--- a/reverts.js
+++ b/reverts.js
@@ -1,18 +1,13 @@
-'use strict'
-
 const revertRe = /^revert\s+"?/i
 
-function isRevert (summary) {
+export function isRevert (summary) {
   return summary && revertRe.test(summary)
 }
 
-function cleanSummary (summary = '') {
+export function cleanSummary (summary = '') {
   if (!isRevert(summary)) {
     return summary
   }
 
   return summary.replace(revertRe, '').replace(/"$/, '')
 }
-
-module.exports.isRevert = isRevert
-module.exports.cleanSummary = cleanSummary
diff --git a/test.js b/test.js
index 0aa1e18..2053aaf 100644
--- a/test.js
+++ b/test.js
@@ -1,20 +1,21 @@
 // NOTE: to run this you will probably need to be authorized with GitHub.
 // Run `./changelog-maker.js` by itself to set this up.
 
-'use strict'
+import { dirname, join } from 'path'
+import { execSync } from 'child_process'
+import { test } from 'tap'
+import chalk from 'chalk'
 
-const path = require('path')
-const { execSync } = require('child_process')
-const { test } = require('tap')
+const __dirname = dirname(new URL(import.meta.url).pathname)
 
 function exec (args) {
-  const stdout = execSync(`"${process.execPath}" ${path.join(__dirname, 'changelog-maker.js')} ${args}`).toString()
+  const stdout = execSync(`"${process.execPath}" ${join(__dirname, 'changelog-maker.js')} ${args}`).toString()
 
   return stdout
 }
 
 test('test basic commit block', (t) => {
-  t.equal(exec('--start-ref=v1.3.9 --end-ref=v1.3.10'),
+  t.equal(exec('--md --start-ref=v1.3.9 --end-ref=v1.3.10'),
     `* \\[[\`e28b3f2813\`](https://github.com/nodejs/changelog-maker/commit/e28b3f2813)] - 1.3.10 (Rod Vagg)
 * \\[[\`ace3af943e\`](https://github.com/nodejs/changelog-maker/commit/ace3af943e)] - Merge pull request #13 from jamsyoung/private-repo-support (Rod Vagg)
 * \\[[\`25ec5428bc\`](https://github.com/nodejs/changelog-maker/commit/25ec5428bc)] - default to repo scope always - revert previous changes (James Young)
@@ -25,7 +26,7 @@ test('test basic commit block', (t) => {
 })
 
 test('test filter-release', (t) => {
-  t.equal(exec('--start-ref=v1.3.9 --end-ref=v1.3.10 --filter-release'),
+  t.equal(exec('--md --start-ref=v1.3.9 --end-ref=v1.3.10 --filter-release'),
     `* \\[[\`ace3af943e\`](https://github.com/nodejs/changelog-maker/commit/ace3af943e)] - Merge pull request #13 from jamsyoung/private-repo-support (Rod Vagg)
 * \\[[\`25ec5428bc\`](https://github.com/nodejs/changelog-maker/commit/25ec5428bc)] - default to repo scope always - revert previous changes (James Young)
 * \\[[\`424d6c22c1\`](https://github.com/nodejs/changelog-maker/commit/424d6c22c1)] - add --private arg to set repo scope, update readme (James Young)
@@ -34,7 +35,7 @@ test('test filter-release', (t) => {
 })
 
 test('test simple', (t) => {
-  t.equal(exec('--start-ref=v1.3.9 --end-ref=v1.3.10 --simple'),
+  t.equal(exec('--start-ref=v1.3.9 --end-ref=v1.3.10'),
     `* [e28b3f2813] - 1.3.10 (Rod Vagg)
 * [ace3af943e] - Merge pull request #13 from jamsyoung/private-repo-support (Rod Vagg)
 * [25ec5428bc] - default to repo scope always - revert previous changes (James Young)
@@ -55,8 +56,8 @@ test:
 })
 
 test('test group, semver labels, PR-URL', (t) => {
-  t.equal(exec('--start-ref=v2.2.7 --end-ref=9c700d29 --group --filter-release --simple'),
-    `* [cc442b6534] - (SEMVER-MINOR) minor nit (Rod Vagg) https://github.com/nodejs/node/pull/23715
+  t.equal(exec('--start-ref=v2.2.7 --end-ref=9c700d29 --group --filter-release'),
+  `${chalk.green.bold('* [cc442b6534] - (SEMVER-MINOR) minor nit (Rod Vagg) https://github.com/nodejs/node/pull/23715')}
 * [4f2b7f8136] - deps: use strip-ansi instead of chalk.stripColor (Rod Vagg)
 * [6898501e18] - deps: update deps, introduce test & lint deps (Rod Vagg)
 * [9c700d2910] - feature: refactor and improve --commit-url (Rod Vagg)
@@ -68,7 +69,7 @@ test('test group, semver labels, PR-URL', (t) => {
 })
 
 test('test simple group, semver labels, PR-URL', (t) => {
-  t.equal(exec('--start-ref=v2.2.7 --end-ref=9c700d29 --group --filter-release'),
+  t.equal(exec('--md --start-ref=v2.2.7 --end-ref=9c700d29 --group --filter-release'),
     `* \\[[\`cc442b6534\`](https://github.com/nodejs/changelog-maker/commit/cc442b6534)] - **(SEMVER-MINOR)** minor nit (Rod Vagg) [nodejs/node#23715](https://github.com/nodejs/node/pull/23715)
 * \\[[\`4f2b7f8136\`](https://github.com/nodejs/changelog-maker/commit/4f2b7f8136)] - **deps**: use strip-ansi instead of chalk.stripColor (Rod Vagg)
 * \\[[\`6898501e18\`](https://github.com/nodejs/changelog-maker/commit/6898501e18)] - **deps**: update deps, introduce test & lint deps (Rod Vagg)
@@ -81,7 +82,7 @@ test('test simple group, semver labels, PR-URL', (t) => {
 })
 
 test('test blank commit-url', (t) => {
-  let actual = exec('--start-ref=v2.2.7 --end-ref=9c700d29 --filter-release --commit-url=http://foo.bar/').split('\n')
+  let actual = exec('--md --start-ref=v2.2.7 --end-ref=9c700d29 --filter-release --commit-url=http://foo.bar/').split('\n')
   actual.splice(0, actual.length - 3)
   actual = actual.join('\n')
   t.equal(actual,
@@ -92,7 +93,7 @@ test('test blank commit-url', (t) => {
 })
 
 test('test blank commit-url', (t) => {
-  let actual = exec('--start-ref=v2.2.7 --end-ref=9c700d29 --filter-release --commit-url=https://yeehaw.com/{ref}/{ref}/{ghUser}/{ghRepo}/').split('\n')
+  let actual = exec('--md --start-ref=v2.2.7 --end-ref=9c700d29 --filter-release --commit-url=https://yeehaw.com/{ref}/{ref}/{ghUser}/{ghRepo}/').split('\n')
   actual.splice(0, actual.length - 3)
   actual = actual.join('\n')
   t.equal(actual,
@@ -104,7 +105,7 @@ test('test blank commit-url', (t) => {
 
 test('test backtick strings in commit messages', (t) => {
   t.equal(
-    exec('--start-ref=ce886b5130 --end-ref=0717fdc946 --filter-release --commit-url=https://yeehaw.com/{ref}/{ref}/{ghUser}/{ghRepo}/'),
+    exec('--md --start-ref=ce886b5130 --end-ref=0717fdc946 --filter-release --commit-url=https://yeehaw.com/{ref}/{ref}/{ghUser}/{ghRepo}/'),
     `* \\[[\`0717fdc946\`](https://yeehaw.com/0717fdc946/0717fdc946/nodejs/changelog-maker/)] - **test**: \\\`commit\\_msg\\\` with an unescaped \\\` backtick char (Antoine du Hamel)
 * \\[[\`9f1d897c88\`](https://yeehaw.com/9f1d897c88/9f1d897c88/nodejs/changelog-maker/)] - **test**: \\\`commit\\_msg\\\` with an escaped \\\\\\\` backtick char (Antoine du Hamel)
 * \\[[\`4a3154bde0\`](https://yeehaw.com/4a3154bde0/4a3154bde0/nodejs/changelog-maker/)] - **test**: \`commit_msg\` starting with a backtick string (Antoine du Hamel)
@@ -118,7 +119,7 @@ test('test backtick strings in commit messages', (t) => {
 
 test('test markdown punctuation chars in commit message and author name', (t) => {
   t.equal(
-    exec('--start-ref=f12fe589c4 --end-ref=f12fe589c4 --filter-release --commit-url=https://yeehaw.com/{ref}/{ref}/{ghUser}/{ghRepo}/'),
+    exec('--md --start-ref=f12fe589c4 --end-ref=f12fe589c4 --filter-release --commit-url=https://yeehaw.com/{ref}/{ref}/{ghUser}/{ghRepo}/'),
     `* \\[[\`f12fe589c4\`](https://yeehaw.com/f12fe589c4/f12fe589c4/nodejs/changelog-maker/)] - **group\\_with\\_underscore**: test commit message (Author\\_name\\_with\\_underscore)
 `)
   t.end()

From 3eba26695819a012200eddf211f68a20fb2e7a49 Mon Sep 17 00:00:00 2001
From: Rod Vagg <rod@vagg.org>
Date: Fri, 3 Dec 2021 18:49:35 +1100
Subject: [PATCH 2/3] chore: remove Node.js v12 support

---
 .github/workflows/test-and-release.yml | 2 +-
 changelog-maker.js                     | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/test-and-release.yml b/.github/workflows/test-and-release.yml
index 4e2baba..ba99aaf 100644
--- a/.github/workflows/test-and-release.yml
+++ b/.github/workflows/test-and-release.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node: [12, 14, 16]
+        node: [14, 16]
         # windows support not quite ready: os: [ubuntu-latest, windows-latest]
         os: [ubuntu-latest]
 
diff --git a/changelog-maker.js b/changelog-maker.js
index f5336d6..ad1f1f3 100755
--- a/changelog-maker.js
+++ b/changelog-maker.js
@@ -3,7 +3,8 @@
 import { existsSync, readFileSync } from 'fs'
 import { join } from 'path'
 import process from 'process'
-import stream from 'stream'
+import { pipeline as _pipeline } from 'stream'
+import { promisify } from 'util'
 import split2 from 'split2'
 import pkgtoId from 'pkg-to-id'
 import commitStream from 'commit-stream'
@@ -13,7 +14,7 @@ import minimist from 'minimist'
 import { processCommits } from './process-commits.js'
 import { isReleaseCommit } from './groups.js'
 
-const { pipeline } = stream.promises
+const pipeline = promisify(_pipeline)
 const debug = _debug('changelog-maker')
 const argv = minimist(process.argv.slice(2))
 const help = argv.h || argv.help

From 61d2293823feee3ea9e1bcd85b939ec8e78e2439 Mon Sep 17 00:00:00 2001
From: Rod Vagg <rod@vagg.org>
Date: Fri, 3 Dec 2021 18:58:55 +1100
Subject: [PATCH 3/3] fix: add back --format=x arg option

---
 README.md          | 11 ++++++++---
 process-commits.js |  4 +++-
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index a129f36..ae013bc 100644
--- a/README.md
+++ b/README.md
@@ -48,9 +48,14 @@ npm i changelog-maker -g
 
 `github-user` and `github-project` should point to the GitHub repository that can be used to find the `PR-URL` data if just an issue number is provided and will also impact how the PR-URL issue numbers are displayed
 
-* `--plaintext`:       print a very simple form, without commit details, implies `--group`
-* `--markdown`:        print a Markdown formatted from, with links and proper escaping
-* `--sha`:             print only the list of short-form commit hashes
+* `--format`:          dictates what formatting the output will have. Possible options are: `simple`, `markdown`, `plaintext`, and `sha`. The default is to print a `simple` output suitable for stdout.
+  - `simple`:            don't print full markdown output, good for console printing without the additional fluff.
+  - `sha`:               print only the 10-character truncated commit hashes.
+  - `plaintext`:         a very simple form, without commit details, implies `--group`.
+  - `markdown`:          a Markdown formatted from, with links and proper escaping.
+* `--sha`:             same as `--format=sha`.
+* `--plaintext`:       same as `--format=plaintext`.
+* `--markdown`:        same as `--format=markdown`.
 * `--group`:           reorder commits so that they are listed in groups where the `xyz:` prefix of the commit message defines the group. Commits are listed in original order _within_ group.
 * `--reverse`:         reverse the order of commits when printed, does not work with `--reverse`
 * `--commit-url`:      pass in a url template which will be used to generate commit URLs for a repository not hosted in Github. `{ref}` is the placeholder that will be replaced with the commit, i.e. `--commit-url=https://gitlab.com/myUser/myRepo/commit/{ref}`
diff --git a/process-commits.js b/process-commits.js
index 0ee0312..0e405e1 100644
--- a/process-commits.js
+++ b/process-commits.js
@@ -7,7 +7,9 @@ import { supportsColor } from 'chalk'
 import { collectCommitLabels } from './collect-commit-labels.js'
 
 function getFormat (argv) {
-  if (argv.sha) {
+  if (argv.format && Object.values(formatType).includes(argv.format)) {
+    return argv.format
+  } else if (argv.sha) {
     return formatType.SHA
   } else if (argv.plaintext || argv.p) {
     return formatType.PLAINTEXT